13. Bedside Procedures

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Procedure Basics

Universal Precautions

Universal precautions should be used whenever an invasive procedure exposes the operator to potentially infectious body fluids. Not all patients infected with transmissible pathogens can be reliably identified. Because pathogens transmitted by blood and body fluids pose a hazard to personnel caring for such patients, particularly during invasive procedures, precautions are required for routine care of all patients whether or not they have been placed on isolation precautions of any type. The CDC calls these universal precautions.

1. Wash hands before and after all patient contact.

2. Wash hands before and after all invasive procedures.

3. Wear gloves in every instance in which contact with blood or body fluid is certain or likely. For example, wear gloves for all venipunctures, for all IV starts, for IV manipulation, and for wound care.

4. Wear gloves once and discard. Do not wear the same pair to perform tasks on two different patients or to perform two different tasks at different sites on the same patient.

5. Wear gloves in every instance in which contact with any body fluid is likely, including urine, feces, wound secretions, and fluid encountered in respiratory tract care, thoracentesis, paracentesis.

6. Wear gown when splatter of blood or body fluids on clothing seems likely.

7. Use additional barrier precautions for invasive procedures in which considerable splatter or aerosol generation is likely. Such splatter does not occur during most routine patient care activities but can occur in the OR, ER, and ICU, during invasive bedside procedures, and during CPR. Always wear a mask when goggles are called for, and always wear goggles when a mask is called for.

Accidental Needlesticks

The FDA has recommended safer needle devices, including devices that place a barrier between hands and needle after use. Needlestick injury is an occupational injury among health care workers in the United States. OSHA estimates that 600,000 800,000 needlestick injuries occur on the job each year. Health care workers are at risk of transmission of more than 20 blood-borne pathogens (eg, HIV, hepatitis B and C viruses). Although it is not possible to completely eliminate the risk of needlestick injury, it has been estimated that 62 88% of sharps injuries can be reduced through the use of devices and procedures designed to protect health care workers from exposed needles. A variety of self-shielding needle devices are on the market (see Heelstick and Fingerstick [Capillary Blood Sampling], IV Techniques, and Venipuncture for examples).

Informed Consent

Before any procedure, counsel the patient about the reasons for the procedure, alternatives, and the risks and benefits. Explaining the various steps is likely to help gain the patient's cooperation and make the procedure easier on both parties. In general, procedures such as bladder catheterization, NG intubation, and venipuncture do not require written informed consent beyond normal hospital sign-in protocols. More invasive procedures, such as thoracentesis or lumbar puncture, require written consent, which must be obtained by a licensed physician.

Preprocedure Patient Assessment

Conduct a complete pre-procedure assessment with every patient undergoing an invasive procedure that may require sedation or conscious sedation should undergo. Assess the patient's airway (ie, how difficult it would be to intubate the patient in an emergency), past medical history including previous complications with anesthetics, history of bleeding problems, and a complete history of allergies to medications or latex. Be aware of the patient's current medications with emphasis on blood thinners (eg, heparin, warfarin [Coumadin]) and be aware of the most recent coagulation parameters. Review any relevant, recent studies directly associated with the anticipated procedure.

Time Out

Most institutions are following JCAHO regulations that require a time out before surgical intervention. During this time the members of the team (nurses, anesthesiologists, surgeons, and others) review the procedure to be performed, make sure that informed consent has been obtained, and check that the procedure will be performed on the correct patient and on the correct part of the body (eg, right or left side of the chest). Although not mandated for bedside procedures, time out appears to be a reasonable safety measure.

Latex Allergy

People with certain medical conditions or in occupations that are heavily exposed to products containing natural rubber latex (NRL) may became sensitized and develop allergic reactions to NRL. It is estimated that 7% of health care workers have allergic reactions; persons with spina bifida have an 18 40% incidence. Any group of patients frequently and intensely exposed to latex, such as those undergoing repeated surgical procedures and treatments such as intermittent catheterization, are at increased risk. Local and systemic allergic reactions can often be dramatic and occasionally are life-threatening. The treatment is the same as for any allergic reaction (remove exposure, administer epinephrine and steroids; see Chapter 21).

If a patient has a latex allergy, it should be noted on prominently displayed signs and on the patient's chart, and the patient should wear an alert bracelet. Latex is found in medical equipment in addition to gloves (eg, anesthesia masks, catheters, ETs, hemodialysis components, NG tubes, drains, and syringes) and in consumer products (eg, balloons, rubber bands, scuba diving equipment, underwear). Most hospitals have an inventory of latex-free products and ORs have latex allergy procedures in place. Nitrile gloves are becoming common in hospitals because of this growing problem.

Basic Equipment

Table 13 1 lists useful collections of instruments and supplies, often packaged together, that aid in completion of the procedures described in this chapter. Local anesthesia is discussed in Chapter 17.

Table 13 1 Instruments and Supplies Used in the Completion of Common Bedside Procedures

Minor Procedure Tray 

Sterile gloves

Sterile towels/drapes

4x4 gauze sponges

Povidone iodine (Betadine) prep solution

Syringes: 5-, 10-, 20-mL

Needles: 18-, 20-, 22-, 25-gauge

1% Lidocaine (with or without epinephrine)

Adhesive tape

Instrument Tray 

Scissors

Needle holder

Hemostat

Scalpel and blade (no. 10 for adult, no. 15 for children or delicate work)

Suture of choice (2-0 or 3-0 silk or nylon on cutting needle; cutting needle best for suturing to skin)

The size of various catheters, tubes, and needles is often designated by French unit (1 Fr = 1/3 mm in diameter) or by needle gauge. Reference listings for these designations are in Figure 13 1A. Designations of surgical scalpels used in the performance of many basic bedside procedures and in the OR are shown in Figure 13 1B.

Figure 13 1.

A. French catheter guide and needle gauge reference. (Courtesy Cook Urological.) B. Commonly used scalpel blades. Left to right: no. 10, 11, 12, 15, and 20. No. 10 is the standard surgical blade; no. 11 is useful for incisions into abscesses or to open the skin for placement of large IV devices; no. 12 is designed to open tubular structures; no. 15 is widely used for bedside procedures and for more delicate work; no. 20 is used to make large incisions.

Amniotic Fluid Fern Test

Indication

• Assessment for rupture of membranes

Materials

• Sterile speculum and swab
• Glass slide and microscope
• Phenaphthazine (Nitrazine) paper (optional)

Procedure

1. Using a sterile speculum, swab a sample of fluid "pooled" in the vaginal vault onto a glass slide and let it air dry.

2. Amniotic fluid yields an arborization, or "fern," pattern seen under 10x magnification. False-positive: cervical mucus collection; however, the ferning pattern of mucus is coarser. Test is unaffected by meconium, vaginal pH, and blood to amniotic fluid ratios > 1:10. Samples heavily contaminated with blood may not fern.

3. Another test for ruptured membranes is performed with Nitrazine paper, which has a pH turning point of 6.0. Normal vaginal pH in pregnancy is 4.5 6.0; amniotic fluid pH is 7.0 7.5. Positive Nitrazine test: color change in the paper from yellow to blue. False-positive: more common with the Nitrazine test; blood, meconium, semen, alkalotic urine, cervical mucus, and vaginal infections can raise the pH.

Complication

• Infection

Arterial Line Placement

Indications

• Continuous BP readings (eg, critically ill patient)
• Facilitation of frequent ABG measurements (eg, patients who need ventilatory support)

Contraindications

• Arterial insufficiency with poor collateral circulation (see Allen test)
• Thrombolytic therapy or coagulopathy (relative)
• Planned cardiac surgery if the radial artery has to be preserved for harvest for CABG (relative)

Materials

• Minor procedure and instrument tray
• Heparin flush solution (1:1000 dilution)
• Arterial line set-up according to local ICU routine (transducer, tubing, and pressure bag with preheparinized saline, monitor)
• Arterial line catheter kit or 20-gauge catheter over needle, 1 2 in (4 5 cm). (Insyte Autoguard shielded IV catheter, Angiocath Autoguard Shielded IV catheter) with 0.025-in (0.6 mm) guidewire (optional)

Procedure

See Figure 13 2.

1. The radial artery is most frequently used and is described here. Other sites, in decreasing preference: ulnar, dorsalis pedis, femoral, brachial, and axillary arteries. Never puncture the radial and ulnar arteries in the same hand; doing so can compromise the blood supply to the hand and fingers.

2. Using the Allen test or Doppler ultrasonography, verify collateral circulation between the radial and ulnar arteries. Prepare the flush bag, tubing, and transducer, paying particular attention to removing air bubbles.

3. Place the forearm on an armboard with a roll of gauze behind the wrist to hyperextend the joint. Prep with povidone iodine, and drape with sterile towels. Wear gloves and mask.

4. Palpate the artery, and choose the puncture site where the artery appears most superficial. Using a 25-gauge needle and 1% lidocaine, raise a very small skin wheal at the puncture site. Draw back on the syringe before injecting lidocaine so as not to inadvertently inject into the artery.

5. a. Standard technique: (See Figure 13 2). While palpating the path of the artery with your nondominant hand, advance the 20-gauge (preferably 1 in [4 cm] long) catheter-over-needle assembly into the artery at a low (< 30-degree) angle. Once "flash" of blood is seen in the hub, advance the entire unit 1 2 mm, so that the needle and catheter are in the artery. If blood flow in the hub stops, carefully pull the entire unit back until flow is reestablished. When flow is established, position the hub of the catheter downward (decreasing the angle between catheter and skin), allowing catheter advancement in a more straight-line direction. Hold the needle steady, and advance the catheter over the needle into the artery. The catheter should slide smoothly into the artery. Activate the safety button on the catheter to automatically shield the needle. Withdraw the shielded needle completely and check for arterial blood flow from the catheter. A catheter that does not spurt blood is not in position. Briefly occlude the artery with manual pressure while the pressure tubing is being connected. Note: The pressure tubing system must be preflushed to clear all air bubbles before connection.

b. Prepackaged kit technique: Kits, sometimes called "quick catheters," with a needle and guidewire can be used for the Seldinger technique (described in step 8). Place the entry needle at a 30-degree angle to the skin site, and insert until a flash of blood rises in the catheter. The catheter does not have to be advanced, but advance both the guidewire portion (orange handle in some kits) and the catheter into the vessel. Remove the wire and connect it to the pressure tubing.

6. If placement is not successful, apply pressure to the site for 5 min and reattempt one or two more times. If still not successful, move to another site, because the artery may undergo spasm, making cannulation more difficult.

7. Suture the catheter in place with 3-0 silk, and apply a sterile dressing. Splint the dorsum of the wrist to limit mobility and stabilize the catheter.

8. If a larger vessel such as the femoral artery is used, consider the Seldinger technique of cannulation: Locate the vessel lumen with a small-gauge, thin-walled needle; pass a 0.035 floppy-tipped J ("J" describes the configuration of the end of the floppy wire) guidewire into the lumen; and use the guidewire to pass a larger catheter into the vessel. Use a 16-gauge catheter assembly at least 6 in (15 cm) long for the femoral artery. Note: If a dilator is used with the kit, take care to dilate only skin and subcutaneous tissue; inadvertent dilation of an artery causes excessive bleeding.

9. Any amount of heparin can make coagulation studies (PTT) inaccurate. If an arterial line sample is obtained and unexpectedly high results are seen, repeat the test and consider conventional venipuncture. Even with use of a 5- to 10-mL discard sample from the line, some heparin can contaminate the line.

10. Always compare the arterial line pressure with a standard cuff pressure. An occasional difference of 10 20 mm Hg is normal and should be considered when monitoring the BP.

Figure 13 2.

Technique of arterial line placement. (Reprinted, with permission, from: Gomella TL [ed] Neonatology: Basic Management, On-Call Problems, Diseases, Drugs, 5th ed. McGraw-Hill, 2004.)

Complications

Thrombosis, hematoma, arterial embolism, arterial spasm, arterial insufficiency with tissue loss, infection, hemorrhage, and pseudoaneurysm formation.

Arterial Puncture

Indications

• Blood gas determinations and acquisition of arterial blood for chemistry determinations (eg, ammonia levels)

Materials

• Cup of ice
• Blood gas sampling kit

or

• 3- to 5-mL syringe
• 23- to 25-gauge needle (radial artery); 20- to 22-gauge (femoral artery)
• Heparin (1000 U/mL), 1 mL
• Alcohol or povidone iodine swabs

Procedure

1. Use heparinized syringe for blood gas and nonheparinized syringe for chemistry determinations. If a blood gas kit is not available, heparinize a 3- to 5-mL syringe by drawing up 1 mL of 1:1000 solution of heparin through a small-gauge needle (23 25 gauge) into the syringe, pulling the plunger all the way back. The heparin is then expelled, leaving only a small coating.

2. In order of preference, use the radial, femoral, or brachial artery. For the radial artery, perform an Allen test to verify patency of the ulnar artery. You do not want to damage the radial artery if there is no flow in the ulnar artery. To perform the Allen test, have the patient make a tight fist. Occlude both the radial and ulnar arteries at the wrist and have the patient open the hand. While maintaining pressure on the radial artery, release the ulnar artery. If the ulnar artery is patent, the hand flushes red within 6 s, and radial puncture can be safely performed. If flushing is delayed or part of the hand remains pale, do not perform the radial puncture because collateral flow is inadequate. Choose an alternative site. Doppler ultrasonography can also be used to determine patency of the ulnar artery.

3. For the femoral artery, use the mnemonic NAVEL to locate groin structures. Palpate the femoral artery just below the inguinal ligament. From lateral to medial the structures are Nerve, Artery, Vein, Empty space, Lymphatic.

4. Prep the area with either chlorhexidine solution or alcohol swab.

5. With sterile gloves, palpate the chosen artery carefully; lidocaine SQ can be used (small needle such as a 25 27 gauge), but this often turns a one-stick procedure into a two-stick procedure. Palpate the artery proximally and distally with two fingers, or trap the artery between two fingers placed on either side of the vessel. Hyperextension of the joint brings the radial and brachial arteries closer to the surface.

6. Hold the syringe like a pencil with the needle bevel up, and enter the skin at a 60- to 90-degree angle. Often you can feel the arterial pulsations as you approach the artery.

7. Maintaining a slight negative pressure on the syringe, obtain blood on the downstroke or on slow withdrawal (after both sides of the artery have been punctured). Aspirate very slowly. A good arterial sample requires only minimal back pressure. If a glass syringe or special blood gas syringe is used, the barrel usually fills spontaneously, and it is not necessary to pull on the plunger.

8. If the vessel is not encountered, withdraw the needle without coming out of the skin, and redirect.

9. After obtaining the sample, withdraw the needle quickly and apply firm pressure at the site for at least 5 min (longer if the patient is receiving anticoagulants. To prevent compartment syndrome from extravasated blood, apply pressure even if a sample was not obtained. Activate the needle reshielding mechanism.

10. If the sample is for a blood gas determination, expel any air from the syringe, mix the contents thoroughly by twirling the syringe between your fingers, remove and dispose of the needle assembly, and make the syringe airtight with a cap. Place the syringe in an ice bath if more than a few minutes will elapse before the sample is processed. Note the inspired oxygen concentration and time of day on the lab slip.

Arthrocentesis (Diagnostic and Therapeutic)

Indications

• Diagnostic. Evaluation of new-onset arthritis; ruling out infection in acute or chronic, unremitting joint effusion
• Therapeutic. Instillation of steroids, drainage of septic arthritis; relief of tense hemarthrosis or effusion

Contraindications

Cellulitis at injection site. Relative contraindication: bleeding disorder; caution if coagulopathy or thrombocytopenia is present or if the patient is receiving anticoagulants.

Materials

• Minor procedure tray; 18- or 20-gauge needle (smaller for finger or toe)
• Ethyl chloride spray can be substituted for lidocaine.
• Two heparinized tubes for cell count and crystal examination
• Microbiology lab's preferred supplies for transporting fluid for bacterial, fungal, AFB culture, and Gram stain; Thayer Martin plate for Neisseria gonorrhoeae (GC)
• Syringe containing a long-acting corticosteroid such as methylprednisolone (Depo-Medrol) or triamcinolone (see Chapter 22) optional for therapeutic arthrocentesis

General Procedures

1. Obtain consent after describing the procedure and complications.

2. Determine the optimal site for aspiration knee, wrist, or ankle (see below); identify landmarks and mark site with indentation or sterile marking pen. Avoid injecting into tendons.

3. If aspiration is followed by corticosteroid injection, maintain a sterile field with sterile implements to minimize risk of infection.

4. Clean the area with chlorhexidine. Let the area dry, and wipe the aspiration site with alcohol, because chlorhexidine can render cultures negative. Let the alcohol dry before beginning the procedure.

5. Using a 25-gauge needle, anesthetize the puncture site with lidocaine; do not inject into the joint space, because lidocaine is bactericidal. Avoid lidocaine preparations with epinephrine, especially in a digit. Alternatively, spray the area with ethyl chloride ("freeze spray") just before needle aspiration.

6. Insert the aspirating needle (18- or 20-gauge, smaller for finger or toe), applying a small amount of vacuum to the syringe. When the capsule is entered, fluid usually flows easily. Remove as much fluid as possible, repositioning the syringe if necessary.

7. If corticosteroid is to be injected, remove the aspirating syringe from the needle (using a hemostat to hold the needle in place may aid when exchanging syringes), which is still in the joint space. (Note: Ensure that the syringe can easily be removed from the needle before step 6). Attach the syringe containing corticosteroid, pull back on the plunger to ensure the needle is not in a vein, and inject contents. Never inject steroids when there is any possibility that the joint is infected. Remove the needle, and apply pressure to the area (leakage of SQ steroids can cause localized atrophy of the skin). In general, the equivalent of 40 mg of methylprednisolone is injected into large joints such as the knee and 20 mg into medium-size joints such as the ankle and wrist. Warn the patient that a postinjection "flare" (pain several hours later) is treated with ice and NSAIDs.

8. Note volume aspirated from the joint. The knee typically contains 3.5 mL of synovial fluid; in inflammatory, septic, or hemorrhagic arthritis, volumes can be higher. A bedside test for viscosity is to allow a drop of fluid to fall from the tip of the needle. Normal synovial fluid is highly viscous and forms a several-inch-long string; viscosity is decreased in infection. A mucin clot test (clot normally forms in < 1 min; delayed result suggests inflammation) once a standard test for RA, is no longer routinely performed.

9. Joint fluid is usually sent for:

• Cell count and diff (purple or green top tube)
• Microscopic crystal exam with polarized light microscopy (purple or green top tube); normally no debris, crystals, or bacteria; urate crystals present with gout; calcium pyrophosphate in pseudogout.
• Glucose (red top tube) (Table 13 2)
• Gram stain and cultures for bacteria, fungi, and AFB as indicated (check with your lab or deliver immediately in a sterile tube with no additives)
• Cytology if malignant effusion is suspected

Table 13 2 Synovial Fluid Analysis and Categories for Differential Diagnosis^a

Parameter	Normal	Noninflammatory	Inflammatory	Septic	Hemorrhagic
Viscosity	High	High	Decreased	Decreased	Variable
Clarity	Transparent	Transparent	Translucent-opaque	Opaque	Cloudy
Color	Clear	Yellow	Yellow to opalescent	Yellow to green	Pink to red
WBC (per mL)	<200	<3000	3000 50,000	>50,000b	Usually <2000
Polymorphonuclear leukocytes (%)	<25%	<25%	50% or more	75% or more	30%
Culture	Negative	Negative	Negative	Usually positive	Negative
Glucose (mg/dL)	Approx. serum	Approx. serum	>25, but < serum	<25, < serum	>25

^aSee Synovial Fluid Interpretation for additional information.

^bMay be lower if antibiotics initiated.

WBC = white blood cells.

Arthrocentesis of the Knee

1. Fully extend the knee with the patient supine. Wait until the patient has a relaxed quadriceps muscle, because its contraction approximates the patella against the femur, making aspiration painful.

2. Insert the needle posterior to the lateral portion of the patella into the patellar femoral groove. Direct the advancing needle slightly posteriorly and inferiorly (Figure 13 3).

3. To inject the knee joint, have the patient sitting down with the leg flexed and enter the knee anteriorly over the medial joint line.

Figure 13 3.

Arthrocentesis of the knee. (Reprinted, with permission, from: Internal Medicine on Call, 4th ed. Haist SA, Robbins JB [eds]. McGraw-Hill, New York, 2005.)

Arthrocentesis of the Wrist

1. The easiest site for aspiration is between the navicular bone and radius on the dorsal wrist. Locate the distal radius between the tendons of the extensor pollicis longus and the extensor carpi radialis longus to the second finger. This site is just ulnar to the anatomic snuff box. Direct the needle perpendicular to the mark (Figure 13 4). The wrist space also can be approached from the ulnar side by placement of the needle just distal to the ulnar bone.

Figure 13 4.

Arthrocentesis of the wrist. (Reprinted, with permission, from: Internal Medicine on Call, 4th ed. Haist SA, Robbins JB [eds]. McGraw-Hill, New York, 2005.)

Arthrocentesis of the Ankle

1. The most accessible site is between the tibia and the talus. Position the angle of foot to leg at 90 degrees. Make a mark lateral and anterior to the medial malleolus and medial and posterior to the tibialis anterior tendon. Direct the advancing needle posteriorly toward the heel (Figure 13 5).

2. The subtalar ankle joint does not communicate with the ankle joint and is difficult to aspirate even for an expert. Be aware that "ankle pain" can originate in the subtalar joint rather than in the ankle.

Figure 13 5.

Arthrocentesis of the ankle. (Reprinted, with permission, from: Internal Medicine on Call, 4th ed. Haist SA, Robbins JB [eds]. McGraw-Hill, New York, 2005.)

Synovial Fluid Interpretation

Normal synovial fluid values and values in disease states are in Table 13 2.

Noninflammatory Arthritis:

Osteoarthritis, traumatic, aseptic necrosis, osteochondritis desiccans

Inflammatory Arthritis:

Gout (usually associated with elevated serum uric acid), pseudogout, RA, rheumatic fever, collagen vascular disease

Septic Arthritis:

Pyogenic bacterial (Staphylococcus aureus, GC, and Staphylococcus epidermidis most common), TB

Hemorrhagic:

Hemophilia or other bleeding diathesis, trauma with or without fracture

Complications

Infection, bleeding, pain. Postinjection flare of joint pain and swelling can occur after steroid injection and persist for as long as 24 h. This complication is believed to be crystal-induced synovitis caused by the crystalline suspension used in long-acting steroids.

Bone Marrow Aspiration and Biopsy

Indications

• Evaluation of unexplained anemia, thrombocytopenia, leukopenia
• Evaluation of unexplained leukocytosis, thrombocytosis; search for malignancy primary to the marrow (leukemia, myeloma) or metastatic to the marrow (small-cell lung cancer, breast cancer)
• Evaluation of iron stores; evaluation of possible disseminated infection (tuberculosis, fungal disease)
• Bone marrow donor harvesting (aspiration)

Contraindications

• Infection, osteomyelitis near the puncture site
• Relative contraindications include severe coagulopathy and thrombocytopenia (may be corrected by platelet transfusion); previous radiation to the region

Materials

• Kits contain all the materials necessary. A technician from the hematology lab or BMT facility must be present to ensure delivery and processing of specimens.

Procedure

1. Explain the procedure to the patient and/or the legally responsible surrogate in detail and obtain informed consent.

2. Local anesthesia usually is all that is needed; if a patient is extremely anxious, premedication with an anxiolytic or sedative such as diazepam (Valium) or midazolam (Versed) or an analgesic is reasonable.

3. Bone marrow can be obtained from numerous sites, such as the sternum and anterior or posterior iliac crest. The posterior iliac crest is the safest and the site of choice (described here). Position the patient on either the abdomen or on the side opposite the side from which the biopsy specimen is to be taken.

4. Identify the posterior iliac crest by palpation and mark the desired biopsy site with indelible ink.

5. Use sterile gloves, mask, and gown, and follow strict aseptic technique.

6. Prep the site with povidone iodine solution and allow it to dry. Use alcohol to wipe the site free of povidone iodine. Drape the surrounding areas.

7. Administer 1% lidocaine intradermally to raise a skin wheal with a 25- or 26-gauge needle; then use a 22-gauge needle to infiltrate the deeper tissues until the periosteum is reached. Advance the needle just through the periosteum and infiltrate lidocaine subperiosteally. Infiltrate an area approximately 2 cm in diameter, using repeated periosteal punctures.

8. Use a no. 11 scalpel blade to make a 2- to 3-mm skin incision over the biopsy site.

9. Insert the bone marrow biopsy needle through the skin incision and advance it with a rotating motion and gentle pressure until the periosteum is reached. Once the needle is firmly seated on the periosteum, advance it through the outer table of bone into the marrow cavity with the same rotating motion and gentle pressure. In general, a slight change in resistance to needle advancement signals entry into the marrow cavity. At this point, advance the needle 2 3 mm.

10. Remove the stylet from the biopsy needle, and attach a 10-mL syringe to the hub of the biopsy needle. Withdraw the plunger on the syringe briskly, and aspirate 1 2 mL of marrow into the syringe. This step can cause severe, instantaneous pain, but slow withdrawal of the plunger or collection of more than 1 2 mL of marrow with each aspiration results in excessive contamination of the specimen with peripheral blood.

11. Use the specimen to prepare coverslips for viewing under the microscope or send it for special studies (cytogenetics, cell markers, culture). Repeated aspiration may be needed to obtain enough marrow for all studies. Certain studies may require heparin or EDTA for collection. Contact the lab before the procedure to confirm specimen collection procedures.

12. For biopsy, replace the stylet and withdraw the needle. Reinsert the needle at a slightly different angle and location (within the area of periosteum anesthetized). Once the marrow cavity has been reentered, remove the stylet and advance 5 10 mm, using the same rotating motion with gentle pressure. Withdraw the needle several millimeters (but not outside the marrow cavity), and redirect it at a slightly different angle and advance again. Repeating several times results in 2 3 cm of core material entering the needle. Rotate the needle rapidly on its long axis in a clockwise and then a counterclockwise manner to sever the specimen from the marrow cavity. Withdraw the needle completely without replacing the stylet. Some physicians prefer to hold a thumb over the open end of the needle to create negative pressure in the needle as it is withdrawn; this step may help prevent loss of the biopsy specimen.

13. Remove the sample by inserting a probe (provided with the biopsy needle) into the distal end of the needle and gently push the specimen the full length of the needle and out the hub end. Attempting to push the specimen out the distal end may damage the specimen. Most biopsy needles are tapered at the distal end, presumably allowing the specimen to expand once in the needle and preventing it from being lost when the needle is withdrawn from the patient.

14. The core biopsy specimen is usually placed in formalin. (Confirm with lab before procedure.)

15. Observe for excess bleeding and apply local pressure for several minutes. Clean the area with alcohol and apply an adhesive bandage or gauze patch. Recommend (not required unless coagulopathic) that the patient assume a supine position and place a pressure pack between the bed or examining table and the biopsy site and apply pressure for 10 15 min. A patient who is stable at this point may resume normal activities.

Complications

Local bleeding and hematoma, retroperitoneal hematoma, pain, bone fracture, infection

Central Venous Catheterization

Indications

• Administration of fluids and medications (peripheral access preferred)
• Administration of hyperalimentation solutions or other hypertonic fluids (eg, amphotericin B) that damage peripheral veins
• Measurement of CVP (see Chapter 20, Central Venous Pressure)
• Acute dialysis or plasmapheresis (Shiley or Quinton catheter)
• Insertion of pulmonary artery catheter or transvenous pacemaker

Contraindications

• Coagulopathy dictates the use of the femoral or median basilic vein approach to minimize complications.

Background

A central venous catheter (or "deep line") is a catheter introduced into the superior or inferior vena cava or one of the main branches of these vessels. One technique (Seldinger technique) involves puncturing the vein with a small needle through which a thin guidewire is placed. The needle is withdrawn, and the intravascular appliance or a sheath through which a smaller catheter will be placed is introduced into the vein over the guidewire. Another technique involves puncturing the vein with a larger bore needle through which the intravascular catheter will fit. This section focuses on the more common Seldinger technique and placement of either a triple-lumen catheter or a sheath through which a smaller catheter (eg, a pulmonary artery catheter) can be placed. The internal jugular and subclavian approaches are commonly used; the femoral approach, although infrequently used, offers several advantages (see Femoral Vein Approach). The PICC line is designed for more long-term outpatient administration of medications and is described in Peripheral Insertion of Central Catheter. Before inserting these catheters, obtain a thorough history, asking about any bleeding diathesis, anticoagulant use, previous catheter placement, history of DVT, and presence of transvenous pacemaker. Note any abnormal laboratory values, especially elevated PT/PTT or low platelets. Correction of any such abnormalities with platelet transfusions, fresh frozen plasma transfusions, vitamin K, or discontinuation of anticoagulation may be required before placement of nonurgent central venous catheters.

Materials

Prepackaged trays contain all the necessary needles, wires, sheaths, dilators, suture materials, and anesthetics needed. If needles, guidewires, and sheaths are collected from different places, make sure that the needle will accept the guidewire, that the sheath and dilator will pass over the guidewire, and that the appliance to be passed through the sheath will fit the inside lumen of the sheath, because sizes are not standard. Supplies should include the following:

• Minor procedure and instrument tray (Table 13 1); 1% lidocaine (mixed 1:1 with sodium bicarbonate 1 mEq/L removes the sting)
• Guidewire (usually 0.035 floppy-tipped J wire)
• Vessel dilator
• Intravascular appliance (triple-lumen catheter or a sheath through which a pulmonary artery catheter can be placed)
• Heparinized flush solution 1 mL of 1:100 units heparin in 10 mL of NS (to fill lumens before placement to prevent clotting during placement)
• Mask, sterile gown, gloves

Subclavian Approach (Left or Right)

The left subclavian approach affords a gentle, sweeping curve to the apex of the right ventricle (preferred site for temporary transvenous pacemaker without fluoroscopy). Hemodynamic measurements are easier from the left subclavian approach; catheters do not have to negotiate an acute angle, as is the case at the junction of the right subclavian vein with the right brachiocephalic vein en route to the superior vena cava. This site is a common one for kinking of the line but is also has the lowest risk of infection. Caution: The thoracic duct is on the left side, and the dome of the pleura rises higher on the left.

Procedure

1. Use sterile technique (chlorhexidine prep, gloves, mask, gown, and a sterile field).

2. Place the patient flat or with head slightly down (Trendelenburg position) in the center or turned to the opposite side. (Note: The "ideal" position is controversial and based on operator preference.) Placing a towel roll along the patient's spine may help.

3. Administer 1% lidocaine and use a 25-gauge needle to make a small skin wheal 1 in (2 cm) below the midclavicle. Then use a larger needle (eg, 22-gauge) to anesthetize the deeper tissues and locate the vein.

4. Attach a large-bore, deep-line needle (a 14-gauge needle with a 16-gauge catheter at least 8 12 in [20 30 cm] long) to a 10 20 mL syringe, and introduce it into the site of the skin wheal.

5. Advance the needle under the clavicle, aiming for a location halfway between the suprasternal notch and the base of the thyroid cartilage. Place your index or middle finger in the sternal notch, and aim for just above your finger (Figure 13 6). The vein is encountered under the clavicle, just medial to the lateral border of the clavicular head of the sternocleidomastoid muscle. In most patients the site is roughly two finger breadths lateral to the sternal notch. Apply gentle pressure on the needle at the skin entrance site to assist in lowering the needle under the clavicle, aiming the tip of the needle toward the sternal notch. Do not aim the needle toward the floor; that is how the pleura can be hit, resulting in pneumothorax.

6. Apply back pressure while advancing the needle deep to the clavicle, but above the first rib, and watch for a "flash" of blood.

7. Free return of blood indicates entry into the subclavian vein. Remember that occasionally the vein is punctured through both walls, and a flash of blood may not appear as the needle is advanced. Therefore, if free return of blood does not occur on needle advancement, withdraw the needle slowly with intermittent pressure. Free return of blood heralds entry of the end of the needle into the lumen. Bright red blood that forcibly enters the syringe indicates that the subclavian artery has been entered. If arterial entry occurs, remove the needle. In most patients, the surrounding tissue will tamponade any bleeding from the arterial puncture. Note: The artery is under the clavicle; holding pressure has little effect on bleeding.

8. a. If you are using an Intracath device, remove the syringe, place a finger over the needle hub, and advance the catheter an appropriate distance through the needle. Withdraw the needle to just outside the skin and snap the protective cap over the tip of the needle.

b. For the Seldinger wire technique, advance the wire through the needle and withdraw the needle. Pulse or ECG should be monitored during wire passage because the wire can induce ventricular arrhythmias. Arrhythmias usually resolve when the wire is pulled out several centimeters. Nick the skin with a no. 11 blade, and advance the dilator approximately 2 in (5 cm); remove the dilator and advance the catheter in over the guidewire (use the brown port on the triple-lumen catheter). While advancing either the dilator or the catheter over the wire, periodically ensure that the wire moves freely in and out. When placing a Cordis (multiport catheter sheath) system, advance the catheter and dilator over the guidewire as one unit (see Chapter 20, Pulmonary Artery Catheters). If the wire does not move freely, it usually is kinked; remove the catheter or dilator and reposition it. Maintain a grip on the guidewire at all times. Remove the wire and attach the IV tubing. Note: The wire used to insert a single-lumen catheter is shorter than the wire supplied with the triple-lumen catheter. Knowledge of this difference is critical when a triple-lumen is exchanged for a single-lumen catheter; use the longer triple-lumen wire and insert the wire into the brown port. Use the Seldinger wire technique to place Shiley (hemodialysis) catheters.

9. Aspirate blood, remove all the air from each of the ports, and flush with saline solution. Attach the catheter to the appropriate IV solution.

10. Securely suture the assembly in place with 2-0 or 3-0 silk. Apply an occlusive dressing with povidone iodine ointment.

11. Obtain a CXR immediately to verify the location of the catheter tip and to rule out pneumothorax. Ideally, the catheter tip lies in the superior vena cava at its junction with the right atrium (about T5). Malpositioned catheters into the neck veins can be used only for saline infusion and not for monitoring or TPN infusion.

12. Catheters that cannot be manipulated into the chest at the bedside can usually be positioned properly during an interventional radiology procedure with fluoroscopy.

Figure 13 6.

Technique for the catheterization of the subclavian vein.

Right Internal Jugular Vein Approach

There are three sites of access to the right internal jugular vein: anterior (medial to the sternocleidomastoid muscle belly), middle (between the two heads of the sternocleidomastoid muscle belly), and posterior (lateral to the sternocleidomastoid muscle belly). The middle approach is most common and is made with well-defined landmarks. The major disadvantage of the internal jugular site is patient discomfort (difficult to dress, uncomfortable when turning the head). Most larger hospitals are equipped with portable ultrasound scanners and needle guides (Site-Rite Ultrasound by Bard) to facilitate accurate internal jugular cannulation, minimizing the incidence of inadvertent carotid artery puncture.

Procedure

1. Sterilize the site with chlorhexidine, and drape the area with sterile towels. Administer local anesthesia with lidocaine in the area to be explored, as noted in the previous section.

2. Place the patient in the Trendelenburg (head down) position.

3. If using a portable ultrasound scanner, pass the head of the scanner through the sterile sheath, and after applying ultrasound gel locate the internal jugular vein (it is larger and more compressible than the carotid artery). Advance the large bore, deep-line needle through the needle guide and watch it enter the vein on the ultrasound monitor. If not using ultrasonography, use a small-bore (21-gauge) needle with syringe to locate the internal jugular vein. It may help to have a small amount of anesthetic in the syringe to inject during exploration if the patient feels discomfort. Some clinicians prefer to leave this needle and syringe in the vein and place the large-bore needle directly over the smaller needle, into the vein. This method is commonly called the "seeker needle" technique.

4. Make sure the internal diameter of the needle used to locate the internal jugular vein is large enough to accommodate the passage of the guidewire (typically 22-gauge or larger).

5. Make the percutaneous entry at the apex of the triangle formed by the two heads of the sternocleidomastoid muscle and the clavicle (Figure 13 7).

6. Direct the needle slightly lateral toward the ipsilateral nipple and enter at a 45-degree angle to the skin.

7. A notch can sometimes be palpated on the posterior surface of the clavicle; this step can help locate the vein in the mediolateral plane because the vein lies deep to this shallow notch.

8. Vein puncture often is accomplished at an unnerving depth of needle insertion and is heralded by sudden aspiration of nonpulsatile venous blood. Bedside Doppler ultrasonography is available in most ORs or ICUs and can aid in localization of the internal jugular vein if the standard techniques fail.

9. Inadvertent carotid artery puncture is common if the needle is inserted medial to where it should be on the middle approach and is common with the anterior approach. With arterial puncture, the syringe fills without negative pressure because of arterial pressure, and bright red blood pulsates from the needle after the syringe is removed. In this case remove the needle and apply manual pressure for 10 15 min.

10. Follow steps 8 12 as for subclavian line to confirm position and end procedure.

Figure 13 7.

Technique for the catheterization of the right internal jugular vein.

Complications

Overall, a safe procedure when the small-bore needle is used to identify the vein.

• Pneumothorax may be detected when a sudden gush of air is aspirated instead of blood. Always obtain a postprocedure CXR to rule out pneumothorax and check line placement. Pneumothorax necessitates chest tube placement in almost all cases, especially when the patient is receiving mechanical ventilation or is a trauma patient. The left-sided approach is associated with higher pneumothorax risk (higher dome of the left pleura).
• Perforation of ET cuffs
• Hemothorax (vascular injury) or hydrothorax (administration of IV fluids into the pleural space)
• Deep venous thrombosis: Greatest risk factor for upper extremity DVT is a history of or the presence of a subclavian or an internal jugular deep line.
• Catheter tip embolus: Never withdraw the catheter through the needle (can shear off the tip).
• Air embolus: Always keep the open end of a deep line covered with a finger. As little as 50 100 mL of air in a vein can be fatal. For suspected air embolization, place the patient's head down, and turn the patient to his or her left side to keep the air in the right atrium. A stat portable CXR will show whether air is present in the heart.

Left Internal Jugular Vein Approach

The left internal jugular vein approach is not commonly used for central lines. Try one of the better options before using this approach. The procedure is similar to the right internal jugular vein approach. In addition to the usual complications, left internal jugular vein approach has unique complications, including inadvertent left brachiocephalic vein and superior vena caval puncture with intravascular wires, catheters, and sheaths and laceration of the thoracic duct with chylothorax.

External Jugular Vein Approach

The external jugular vein is a safe approach to central venous catheterization, but the method is technically demanding owing to difficulty threading the catheter into the central venous system. This site is uncomfortable for the patient because the dressing and IV tubing are on the neck. If the central venous system cannot be entered, the external jugular vein is also a site of last resort for placing a standard IV catheter ("peripheral") for administration of routine nonsclerosing IV fluids. The external jugular vein is usually visible with the patient in a 30-degree Trendelenburg position. The vein, located in the SQ tissues, crosses the sternocleidomastoid muscle arising from just behind the angle of the jaw inferiorly where it drains into the subclavian vein just lateral to the inferior aspect of the sternocleidomastoid muscle.

Procedure

1. Place the patient in the Trendelenburg position with the head turned away from the side of insertion. Prep and drape the neck from the ear to the subclavicular area.

2. Have the patient perform the Valsalva maneuver or gently occlude the vein near its insertion into the subclavian vein to help engorge the vein.

3. At the midpoint of the vein, make a skin wheal with a 25-gauge needle and lidocaine solution. Use a 21-gauge needle to anesthetize the deeper SQ tissue and to locate the vein.

4. Remove the syringe from the needle and insert a floppy-tipped J wire into the needle. Use the guidewire with gentle pressure to negotiate the turns into the intrathoracic portion of the venous system. With difficult wire passage, have the patient turn his or her head slightly to help direct the wire. Never forcibly push the wire. As a last resort, use fluoroscopy to direct the wire into the superior vena cava.

5. Once a sufficient length of guidewire is passed, remove the needle.

6. Nick the skin with a no. 11 blade to accommodate the catheter; advance the catheter over the guidewire, and remove the guidewire. Aspirate blood from the end of the catheter to confirm venous placement.

7. Follow steps 8 12 as for placement through the subclavian vein.

Complications

See Right Internal Jugular Vein Approach.

Femoral Vein Approach

The femoral vein approach is safe (arterial and venous sites are easily compressible), and pneumothorax is not possible. Placement can be accomplished without interrupting CPR. This site can be used to place a variety of intravascular appliances, including temporary pacemakers, pulmonary artery catheters (expertise with fluoroscopy may be needed), and triple-lumen catheters. The main disadvantages are high risk of sepsis, the immobilization it causes, and the need for fluoroscopy to ensure proper placement of pulmonary artery catheters and transvenous pacemakers.

Procedure

1. Place the patient in the supine position.

2. Use sterile preparation and appropriate draping. Administer local anesthesia in the area to be explored.

3. Palpate the femoral artery. Use the NAVEL technique to locate the vein. If the arterial pulse is difficult to palpate, Doppler ultrasonography may aid in locating the artery.

4. Guard the artery with the fingers of one hand.

5. Explore for the vein just medial to your fingers with a needle and syringe as described previously.

6. It may be helpful to have a small amount of anesthetic in the syringe to inject with exploration.

7. Direct the needle cephalad at about a 30-degree angle and insert it below the femoral crease.

8. Puncture is heralded by the return of venous, nonpulsatile blood on application of negative pressure to the syringe.

9. Advance the guidewire through the needle.

10. The guidewire should pass with ease into the vein to a depth at which the distal tip of the guidewire is always under your control, even when the sheath dilator or catheter is placed over the guidewire.

11. Remove the needle once the guidewire has advanced into the femoral vein.

12. For catheter size > 6 Fr, make a skin incision with a no. 11 scalpel blade and use a vessel dilator. Advance the catheter along with the guidewire into the femoral vein. Maintain control on the distal end of the guidewire.

13. Follow steps 8 12 as for the subclavian line.

Complications

The femoral site has the highest risk of contamination and sepsis. If an occlusive dressing can remain in place and free from contamination, this option is safe.

DVT has occurred after femoral vein catheterization. The risk of DVT increases if the catheter remains in place for a prolonged period.

Uncontrolled retroperitoneal bleeding can occur if the iliac or common femoral artery is inadvertently punctured above the inguinal ligament.

Removal of a Central Venous Catheter (Any Site)

1. Turn off the IV flow.

2. Place the patient lying down in slight Trendelenburg position. Cut the retention sutures, and gently withdraw the catheter. Visually inspect the catheter to ensure it is intact.

3. Apply pressure for at least 2 3 min, and apply a sterile dressing. Undo the Trendelenburg positioning, and place the patient in reverse Trendelenburg to decrease venous engorgement.

Removal of Tunneled Catheters

Permacath (or Hickman or Broviac) catheters are tunneled catheters placed in the OR or interventional radiology suite. These catheters pass through from the internal jugular or the subclavian vein, and are then tunneled subcutaneously and emerge from the chest wall. They also have an antibiotic-impregnated cuff near the skin exit site to prevent infection and promote tissue growth.

1. Wearing sterile gloves, gown, and mask, prep the patient as if placing a central line. Be sure to prep the catheter outside of the skin as well.

2. Cut skin sutures holding catheter in place.

3. Infiltrate field with 1% lidocaine using 25-gauge needle. Use caution to not inject directly into catheter (infiltrate only surrounding tissue). Palpate the antibiotic cuff through the skin. It should be a few centimeters from skin exit site, although this distance varies by catheter type and length of catheter outside the skin.

4. If it has been placed within the past 2 4 wk, the catheter may slide out with gentle traction, much like other central lines. More commonly, however, the antibiotic disk causes an inflammatory response that creates a tissue cuff around the cuff and catheter track. Begin by using a hemostat or scissors placed through the exit site to bluntly separate the surrounding connective tissue from the cuff. You may have to use a scissors to sharply cut some of this soft tissue. Take great care not to cut the catheter itself.

5. Once the cuff is free, gently attempt to pull out the catheter. If it does not release with gentle traction, do not pull harder because the catheter can snap, part of it being drawn into right atrium.

6. If the catheter is still not free, continue to cut tissue immediately surrounding it down to the catheter itself. Once you see the white color of the catheter, gently pull again and slide it out.

7. Once the catheter is removed, hold pressure for at least 5 min both at the site of entry into the vein (the internal jugular or subclavian) and at the exit site from the skin. Undo the Trendelenburg positioning.

8. If the cuff is very far from the skin exit site of the catheter, make a counterincision through the skin higher on the chest wall to aid in freeing the cuff from surrounding tissue at that location.

Chest Tube Placement (Closed Thoracostomy, Tube Thoracostomy)

Indications

• Pneumothorax (simple or tension)
• Hemothorax, hydrothorax, chylothorax, or empyema evacuation
• Pleurodesis for chronic recurring pneumothorax or effusion refractory to standard management (eg, malignant effusion)

Materials

• Chest tube (Adult, 16 24 Fr for pneumothorax, 28 36 Fr for hemothorax or pleural effusion; newborn, 12 18 Fr; 1 2 y, 14 24 Fr; 5 y, 20 32; > 5 y, as for adult)
• Water-seal drainage system (eg, Pleur-Evac) with connecting tubing to wall suction
• Minor procedure tray and instrument tray (see Table 13 1)
• Silk or nylon suture (0 to 2-0)
• Petrolatum gauze (Vaseline) (optional)
• 4 x 4 gauze dressing and cloth tape
• Pulse oximeter monitoring (recommended)

Background

A chest tube is usually placed to manage an ongoing intrathoracic process that cannot be managed with simple thoracentesis. The traditional methods of chest tube placement are described. Use of percutaneous tube thoracostomy kits for the Seldinger technique (used for small pneumothoraces when there is no risk of ongoing air leak) is contraindicated in severe conditions (eg, empyema, major pneumothorax > 20%, tension pneumothorax, chronic effusion). This procedure can be painful and may require conscious sedation.

Procedure

1. Before placing the tube, review the CXR unless an emergency does not allow time. For pneumothorax, choose a high anterior site (2nd or 3rd ICS, midclavicular line, or subaxillary position). Subaxillary placement leaves the best appearance. Place a low lateral chest tube in the 5th or 6th ICS in the midaxillary line and direct it posteriorly for fluid removal (usually corresponds to the inframammary crease.) In traumatic pneumothorax, use a low lateral site because it is usually associated with bleeding. In rare instances loculated apical pneumothorax or effusion may necessitate placement of an anterior tube in the 2nd ICS at the midclavicular line. When a tube is placed on the right side, the right hemidiaphragm may be slightly elevated because of the anatomic position of the liver. Insert the tube above the diaphragm in the pleural space.

2. Choose the appropriate chest tube. Use a 16- to 24-Fr tube for pneumothorax and 28 36 Fr for fluid removal. A "thoracic catheter" has multiple holes and works best for nearly all purposes.

3. Position the patient in an appropriate manner. If the patient is supine, have him or her raise the ipsilateral arm over the head to expose the rib space. If the patient is in the lateral decubitus position, have him or her place the ipsilateral arm on a bedside tray table.

4. Wear mask, hat, gown, and sterile gloves. Prep the area with chlorhexidine solution and drape it with sterile towels. Use lidocaine (with or without epinephrine) to anesthetize the skin, intercostal muscle, and periosteum of the rib; start at the center of the rib and gently work over the top. Remember, the neurovascular bundle runs under the rib (Figure 13 8). The needle then can be gently "popped" through the pleura, and the aspiration of air or fluid confirms the correct location for the chest tube. Back out the needle slowly until no fluid or air is aspirated just outside the parietal pleura, and inject lidocaine. There is no benefit in injecting lidocaine inside the pleural space. If the procedure is elective, the patient is extremely anxious, and the patient's respiratory status is not compromised, sedation occasionally is helpful. When the procedure is performed under conscious sedation with anxiolytics and IV narcotics, place the patient in a monitored setting.

5. Make a 2- to 3-cm transverse incision over the center of the rib with a no. 15 or no. 11 scalpel blade. Use a blunt-tipped clamp to dissect over the top of the rib and make a SQ tunnel (see Figure 13 8).

6. Puncture the parietal pleura with the hemostat, and spread the opening. Be careful not to injure the lung parenchyma with the hemostat tips. If the tube is inserted for a pneumothorax, a rush of air usually is heard on entry into the pleural cavity. If the tube is placed for effusion, fluid under pressure may be released at this time. Insert a gloved finger into the pleural cavity to gently clear any clots or adhesions and to make certain the lung is not accidentally punctured by the tube.

7. Carefully insert the tube into the desired position with a hemostat or gloved finger as a guide. Make sure all the holes in the tube are in the chest cavity. Attach the end of the tube to a water-seal or Pleur-Evac suction system. One indication of proper placement in the pleural place is fogging on the inner tubing of the chest tube that varies with respiration. To guarantee intrapleural position, make sure you observe respiratory variation within the tube or suction system to guarantee intrapleural position. Some chest tubes have sharp trocars that are used to pierce the chest wall and place the chest tube simultaneously with minimal amounts of dissection. These instruments are extremely dangerous and are usually placed in the anterior high position (ie, 2nd, 3rd, or 4th ICS).

8. Suture the tube in place. Place a heavy silk or polypropylene (0 or 2-0) suture through the incision next to the tube. Tie the incision together, then tie the ends around the chest tube. Make sure to wrap the suture around the tube several times. Tie the suture around the tube tightly enough that the tubing dimples slightly but not so tightly as to occlude the lumen. This step prevents the tube from slipping through the suture. As an alternative, place a purse-string suture (or "U stitch") around the insertion site. Make sure all of the suction holes are in the chest cavity before the tube is secured.

9. Cover the insertion site with plain gauze. Make the dressing as airtight as possible with tape, and secure all connections in the tubing to prevent accidental loss of the water seal. Some physicians wrap the insertion site with petrolatum (Vaseline or Xeroform) gauze, but these materials can be troublesome (ie, they are not water soluble and act as a foreign body), inhibit wound healing, and may not actually seal the site.

10. Start suction (usually 20 cm water in adults, 16 cm in children) and obtain a portable CXR immediately to check placement of the tube and to evaluate for residual pneumothorax or fluid.

Figure 13 8.

Chest tube procedure for making a subcutaneous tunnel. The skin incision is lower than the thoracic wall entry site. If a patient has signs of tension pneumothorax (acute shortness of breath, hypotension, distended neck veins, tachypnea, tracheal deviation) before a chest tube is placed, urgent treatment is needed. Insert a 14-gauge needle into the chest in the 2nd ICS in the midclavicular line to rapidly decompress the tension pneumothorax and proceed with chest tube insertion. Do not wait for chest x-ray confirmation before inserting a needle into the chest if the diagnosis of tension pneumothorax is suspected. (Reprinted, with permission, from: Gomella TL [ed] Neonatology: Basic Management, On-Call Problems, Diseases, Drugs, 5th ed. McGraw-Hill, 2004.)

Chest Tube Placement Using Seldinger Technique

Kits for chest tube insertion by the Seldinger technique are good for nonemergency chest tube placement, make the tube easier to insert, and cause less patient discomfort than other equipment.

1. After sterile prepping and draping, anesthetize the skin over the desired ICS (see Procedures). Insert the needle over the rib space to avoid injury to the intercostal bundle.

2. Once air (from pneumothorax) or fluid (from effusion) is aspirated, introduce a wire, serial dilators, and finally the desired chest tube. Secure the chest tube to the skin and connect it to the Pleur-Evac system as described earlier.

Chest Tube Removal

1. Verify that the pneumothorax or hemothorax is cleared. Check for air leak by having the patient cough; observe the water-seal system for bubbling that indicates either a system (tubing) leak or persistent pleural air leak.

2. Take the tube off suction but not off water seal, and cut the retention suture. Have the patient inspire deeply and perform the Valsalva maneuver while you apply pressure with petrolatum gauze or with a sufficient amount of antibiotic ointment on 4 x 4 gauze with additional 4 x 4 gauze squares. Pull the tube rapidly while the patient performs the Valsalva maneuver, and make an airtight seal with tape. Check an "upright" exhalation CXR for pneumothorax.

Pleurodesis

1. Used for recurrent pneumothorax or in recurrent malignant effusion with the goal to obliterate pleural space. It is an uncomfortable procedure, and sedation with a short-acting narcotic is recommended. Sclerosing agents used include doxycycline (500 1000 mg in 100 mL NS), talc (2 g/100 mL NS), and bleomycin (60 units/100 mL NS).

2. After the chest tube is in place, inject 20 40 mL 1% lidocaine into the tube and allow to enter the pleural space. Clamp the tube, and move the patient through various positions (Trendelenburg, reverse Trendelenburg, right and left lateral decubitus) to allow the lidocaine to disperse.

3. Connect the syringe containing the sclerosing agent to the chest tube and release the clamp. Inject the agent and clamp the tube for 4 h. It is important to use sterile technique when injecting into the tube because the pleural cavity is a sterile one. If at any time during clamping the patient experiences severe dyspnea or hypoxia, unclamp the tube because the lung may have collapsed and needs to be re-expanded.

4. Unclamp the tube and connect it to the Pleur-Evac suction device for 24 48 additional hours. Remove the tube after drainage is minimal and a CXR shows no pneumothorax.

5. To prevent tension pneumothorax or subcutaneous emphysema if sclerosing is performed for a persistent air leak, do not clamp the chest tube. Place the chest tubing system on water-seal mode over an IV pole to prevent drainage of sclerosing agent but to allow air to escape if pressure develops within the chest. After 4 h, take down the tubing system from the IV pole, and place the chest tube back on suction for 24 48 h.

Complications

Infection, bleeding, lung damage, SQ emphysema, persistent pneumothorax or hemothorax, poor tube placement, cardiac arrhythmia

Cricothyroidotomy (Needle and Surgical)

Indications

• Immediate mechanical ventilation when an endotracheal or orotracheal tube cannot be placed (eg, severe maxillofacial trauma, excessive oropharyngeal hemorrhage)

Contraindications

• Child < 12 y; use needle approach instead

Basic Materials

• Oxygen connecting tubing, high-flow oxygen source (tank or wall)
• Bag ventilator

Needle Cricothyroidotomy

• 12- to 14-gauge catheter-over-needle assembly (Angiocath or other)
• 6 12-mL syringe
• 3-mm pediatric ET adapter

Surgical Cricothyroidotomy (Minimum Requirements)

• Minor procedure and instrument tray (Table 13 1) plus tracheal spreader if available
• No. 5 7 tracheostomy tube (6- to 8-Fr ET can be substituted)
• Tracheostomy tube adapter to connect to bag mask ventilator

Procedure

Needle Cricothyroidotomy

1. With the patient supine, place a roll behind the shoulders to gently hyperextend the neck.

2. Palpate the cricothyroid membrane, which resembles a notch between the caudal end of the thyroid cartilage and the cricoid cartilage. Prep the area with povidone iodine solution. Local anesthesia can be used if the patient is awake.

3. Mount the syringe on the 12- or 14-gauge catheter-over-needle assembly, and advance the syringe through the cricothyroid membrane at a 45-degree angle, applying back pressure on the syringe until air is aspirated.

4. Advance the catheter, and remove the needle. Attach the hub to a 3-mm ET adapter that is connected to the oxygen tubing. Use a Y-connector or a hole in the side of the tubing to turn the flow on and off, allowing oxygen to flow at 15 L/min for 1 2 s on, then 4 s off.

5. The needle technique is only useful for about 45 min because the exhalation of CO₂ is suboptimal.

Surgical Cricothyroidotomy

1. Follow steps 1 and 2 as for needle cricothyroidotomy.

2. Make a 3- to 4-cm vertical skin incision through the cervical fascia and strap muscles in the midline over the cricothyroid membrane. Expose the cricothyroid membrane, and make a horizontal incision. Insert the knife handle and rotate it 90 degrees to open the hole in the membrane. As an alternative, use a hemostat or tracheal spreader to dilate the opening.

3. Insert a small (5 7 mm) tracheostomy tube, inflate the balloon (if present), and secure it in position with the attached cotton tapes. Because the procedure is performed in an emergency, if a tracheostomy tube is not immediately available, use a smaller diameter ET (6 7 Fr).

4. Attach to oxygen source and ventilate. Listen to the chest for symmetrical breath sounds.

5. Replace a surgical cricothyroidotomy with a formal tracheostomy after the patient's condition has stabilized, generally within 24 36 h.

Complications

Bleeding, esophageal perforation, SQ emphysema, pneumomediastinum and pneumothorax, CO₂ retention (especially with the needle procedure)

Culdocentesis

Indications

• Diagnostic technique for problems of acute abdominal pain in women
• Evaluation of female patient with signs of hypovolemia and possible intraabdominal bleeding
• Evaluation of ascites, especially in possible cases of gynecologic malignant disease

Materials

• Speculum
• Antiseptic swabs
• Chlorhexidine
• 1% lidocaine
• 18- to 21-gauge spinal needle
• 2 (10 mL) syringes and tenaculum

Procedure

1. Perform a careful pelvic exam to document uterine position and rule out pelvic mass at risk of perforation by the culdocentesis.

2. Obtain informed consent, and prep the vagina with antiseptic (eg, chlorhexidine).

3. Using the long needle, inject 1% lidocaine submucosally in the posterior cervical fornix before applying the tenaculum.

4. Improve traction by applying the tenaculum to the posterior cervical lip.

5. Connect an 18- to 21-gauge spinal needle to a 10-mL syringe filled with 1 mL of air.

6. Moving the needle forward through the posterior cervical fornix, apply light pressure to the syringe until the air passes. Maintain traction on the tenaculum while advancing the spinal needle to maximize the surface area of the cul-de-sac for needle entry.

7. After the abdomen has been entered, ask the patient to elevate herself on her elbows to allow gravity drainage into the area of needle entry. Apply negative pressure to the syringe. Slowly rotating the needle and slowly removing it may aid in detection and aspiration of a pocket of fluid.

8. If the first culdocentesis attempt is not successful, repeat the procedure with a different angle of approach.

9. Although perforation of a viscus is a possibility, the complication rate of culdocentesis is low. Fresh blood that clots rapidly is probably the result of traumatic tap, and the procedure can be repeated.

10. If blood is aspirated, spin it for HCT, and place it in an empty glass test tube to determine the presence or absence of a clot. Failure of blood to clot suggests old hemorrhage.

12. If pus is aspirated, send specimens for GC, aerobic, anaerobic, Chlamydia, Mycoplasma, and Ureaplasma cultures.

13. If a malignant tumor is suspected, send fluid for cytologic evaluation.

Complications

Infection, hemorrhage, air embolus, perforated viscus

Doppler Pressures

Indications

• Evaluation of peripheral vascular disease (ankle/brachial [A/B] or ankle/arm [A/I] index)
• Routine BP measurement in infants or critically ill adults

Materials

• Doppler flow monitor
• Conductive gel (lubricant jelly can also be used)
• BP cuff

Procedure (a/B or a/a Index)

1. Determine the BP in each arm.

2. Measure the pressures in the popliteal arteries by placing a BP cuff on the thigh. The pressures in the dorsalis pedis arteries (on the top of the foot) and the posterior tibial arteries (behind the medial malleolus) are determined with a BP cuff on the calf.

3. Apply conductive jelly and place the Doppler transducer over the artery. Inflate the BP cuff until the pulsatile flow is no longer heard. Deflate the cuff until the flow returns. This is the systolic, or Doppler, pressure. Note: The Doppler examination does not give the diastolic pressure, and a palpable pulse need not be present for Doppler studies.

4. The A/B or A/A index is often computed from Doppler pressure. It is equal to the best systolic pressure in the ankle (usually from the posterior tibial artery) divided by the systolic pressure in the arm. An A/B index > 0.9 is usually normal, and an index < 0.5 is usually associated with significant peripheral vascular disease. In patients with long-standing diabetes, the foot arteries can be severely calcified, and thus ankle systolic pressures may be falsely elevated because of the pressure needed to compress the calcified arteries.

Electrocardiogram

Basic ECG interpretation is described in Chapter 19.

Indications

• Evaluation of chest pain and other cardiac conditions

Materials

• ECG machine with paper and lead electrodes
• Adhesive electrode pads

Procedure

Most hospitals have fully automated ECG machines. Become acquainted with the machine at your hospital before using it. The following is a general outline.

1. Start with the patient in a comfortable, recumbent position. Explain the steps of the procedure to the patient. Instruct the patient to lie as still as possible to cut down on artifacts in the tracing.

2. Plug in the ECG machine and turn it on.

3. Attach the electrodes as follows:

a. Patient Cables. A standard ECG machine has five lead wires, one for each limb and one for the chest leads. Newer machines have six precordial electrodes, all of which are placed in the proper positions before the procedure. The leads may be color-coded in the following manner:

• RA: White right arm
• LA: Black left arm
• RL: Green right leg
• LL: Red left leg
• C: Brown chest

b. Limb Electrodes. Newer machines have self-adhering electrode pads. Older machines have flat, rectangular plates held in place by straps that encircle the limb. Place each electrode on the limb indicated, wrist or ankle, usually on the ventral surface. In case of amputation or presence of a cast, placing the lead on the shoulder or groin has minimal effect on the tracing.

c. Chest (Precordial) Electrodes. With newer machines all leads can be placed before the ECG is run with all pads applied at the same time. This makes locating the proper positions quick and easy (Figure 13 9). Older units have a suction cup chest electrode that is brown and designated by the letter "C." It is attached in sequence to each of the positions on the precordium. Precordial leads are placed as follows:

• V₁ = 4th ICS just to the right of the sternal border
• V₂ = 4th ICS just to the left of the sternal border
• V₃ = midway between leads V₂ and V₄
• V₄ = midclavicular line in the 5th ICS
• V₅ = anterior axillary line at the same level as V₄
• V₆ = midaxillary line at the same level as leads V₄ and V₅

4. When everything is ready, follow the directions for your particular machine to obtain the ECG tracing. It should include 12 leads: I, II, III, AVR, AVL, and V₁ V₆. Standard paper speed is 25 mm/s.

5. Label the tracing with the patient's name, date, time, and any other useful information, such as medications, and your name. A routine 12-lead ECG should take 4 8 min.

Figure 13 9.

Location of the precordial chest leads used in obtaining a routine ECG.

Helpful Hints

1. The second rib inserts at the sternal angle, and therefore the second ICS is directly inferior to the sternal angle. Feel down two more ICSs and you have the fourth ICS to position V₁ and V₂.

2. Learn the color scheme for the leads; doing so can be very useful in an emergency. Some memory aids include

a. Red and green go to the legs: "Christmas on the bottom" or "When driving your car you use your left leg to brake (red light) and your right leg to go (green light)."

b. Black (left) and white (right) go to the arms: "Remember white is right and black is left."

c. Brown is for the chest.

Endotracheal Intubation

Indications

• Airway management during CPR
• Any indication for using mechanical ventilation (eg, respiratory failure, coma, general anesthesia)

Contraindications

• Massive maxillofacial trauma (relative)
• Fractured larynx
• Suspected cervical spinal cord injury (relative)

Materials

• Endotracheal tube of appropriate size (Table 13 3)
• Laryngoscope handle and blade (straight [Miller] or curved [MAC]; size no. 3 for adults, no. 1 1.5 for small children)
• 10-mL syringe, adhesive tape, benzoin
• Suction equipment (Yankauer suction)
• Malleable stylet (optional)
• Oropharyngeal airway

Table 13 3 Recommended Endotracheal Tube Sizes

Patient	Internal Diameter (mm)
Premature infant	2.5 3.0	(uncuffed)
Newborn infant	3.5	(uncuffed)
3 12 mo	4.0	(uncuffed)
1 8 y	4.0 6.0	(uncuffed)a
8 16 y	6.0 7.0	(cuffed)
Adult	7.0 9.0	(cuffed)

^aRough estimate is to measure the little finger.

Procedure

1. Orotracheal intubation is most commonly used and is described here. In suspected cervical spine injury, nasotracheal intubation is preferred.

2. Before attempting endotracheal intubation (bag mask or mouth to mask), ventilate any patient who is hypoxic or apneic. Avoid prolonged periods of no ventilation if the intubation is difficult. A rule of thumb is to hold your breath while attempting intubation. When you need to take a breath, so must the patient. Resume ventilation, and reattempt intubation in a minute or so.

3. Extend the laryngoscope blade to 90 degrees to verify the light is working, and check the balloon on the tube (if present) for leaks.

4. Place the patient's head in the "sniffing position" (neck extended anteriorly and the head extended posteriorly). Use suction to clear the upper airway if needed.

5. Hold the laryngoscope in your left hand, hold the mouth open with your right hand, and use the blade to push the tongue to patient's left while keeping it anterior to the blade. Advance the blade carefully toward the midline until the epiglottis is visualized. Use suction if needed.

6. If a straight laryngoscope blade is used, pass it under the epiglottis and lift upward to visualize the vocal cords (Figure 13 10, below). If the curved blade is used, place it anterior to the epiglottis (into the vallecula) and gently lift anteriorly. In either case, do not use the handle to pry the epiglottis open, but rather gently lift to expose the vocal cords (ie, minimize torquing action).

7. While maintaining visualization of the cords, grasp the tube in your dominant hand and pass it through the cords. With more difficult intubations, use the malleable stylet to direct the tube.

8. If the patient may have eaten recently, have an assistant place gentle pressure over the cricoid cartilage to occlude the esophagus and prevent aspiration during intubation. "Cricoid pressure" can also facilitate visualization of the vocal cords in patients whose larynx is situated more anteriorly than usual.

9. When using a cuffed tube (adults and older children), gently inflate with air using a 10-mL syringe until the seal is adequate (about 5 mL). Ventilate the patient while auscultating and visualizing both sides of the chest to verify positioning. Failure of the left side to ventilate may signify that the tube has been advanced down the right mainstem bronchus. Withdraw the tube 1 2 cm, and recheck the breath sounds. Also auscultate over the stomach to ensure the tube is not mistakenly placed in the esophagus. Confirm positioning with a CXR. The tip of the ET should be a few centimeters above the carina. If a CO₂ colorimetric device is available, confirm placement of the tube by connecting the device to the ET between the adapter and the ventilating device.

10. Tape the tube in position, and insert an oropharyngeal airway to prevent the patient from biting the tube. Consider an orogastric tube to prevent regurgitation.

Figure 13 10.

Endotracheal intubation using a curved laryngoscope blade.

Complications

Bleeding, oral or pharyngeal trauma, improper tube positioning (esophageal intubation, right mainstem bronchus), aspiration, tube obstruction or kinking

Fever Work-Up

Although not a standard "bedside procedure," fever work-up involves judicious use of invasive procedures. The true definition of a fever can vary from service to service. General guidelines to follow are that a fever is an oral temperature > 100.4 F (38 ) on a medical or surgical service and a rectal temperature of 101 F (38.3 C) or oral temperature 100 F (37.7 C) in an infant or immunocompromised patient. When evaluating a patient for a fever, consider whether the temperature is oral, rectal, tympanic, or axillary (rectal and tympanic temperatures are about 1 F higher and axillary temperatures are about 1 F lower than oral); whether the patient has drunk hot or cold liquids or smoked around the time of the determination; and whether the patient is taking antipyretics. Also, remember body temperature is highest at about 8 PM (+ 0.5 F from 98.6 F) and lowest at about 4 AM ( 1 to 1.5 F). Differential diagnosis of fever and fever of unknown origin are discussed in Chapter 3.

General Fever Work-Up

1. Quickly review the chart and medication record if the patient is not familiar to you.

2. Question and examine the patient to locate any obvious sources of fever.

a. Ears, nose, sinuses and throat: Especially in children

b. Neck: Pain with flexion

c. Nodes: Adenopathy

d. Lungs: Rales (crackles), rhonchi (wheezes), decreased breath sounds, or dullness to percussion. Can the patient generate an effective cough?

e. Heart: A new or changing heart murmur, which may suggest endocarditis

f. Abdomen: Presence or absence of bowel sounds, guarding, rigidity, tenderness, bladder fullness, or costovertebral angle tenderness

g. Genitourinary: If a Foley catheter is in place, note appearance of the urine, grossly and microscopically

h. Rectal Exam: Tenderness or fluctuance that suggests an abscess or acute prostatitis

i. Pelvic Exam: Especially in the postpartum patient or sexually active woman with multiple partners

j. Wounds: Erythema, tenderness, swelling, or drainage from surgical sites

k. Extremities: Signs of inflammation at IV sites. Look for thigh or calf tenderness and swelling.

l. Miscellaneous: Consider the possibility of a drug fever (eosinophil count on the CBC may be elevated) or NG tube fever. Look at every IV site looking for cellulitis or IV infiltrates and also remember central lines, Infus-a-port devices, and PICC lines as potential sources of fever. Do all of the above before beginning to investigate the less common or less obvious causes of a fever.

3. Laboratory Studies

a. Basic: CBC with diff, UA, cultures and Gram stains: urine, blood, sputum, wound, spinal fluid (especially in children < 4 6 mo old)

b. Other: Order based on clinical findings:

(i) Radiographic: Chest or abdominal films, CT or ultrasound exam

(ii) Invasive: LP, thoracentesis, paracentesis are more aggressive procedures that may be indicated.

Miscellaneous Fever Facts

1. Causes of Fever in the Postop Patient: Think of the "Six Ws":

a. Wind: Atelectasis secondary to intubation and anesthesia is the most common cause of immediate postop fever. To treat, have the patient sitting up and ambulating, using incentive spirometry, P&PD, etc.

b. Water: UTI; may be secondary to presence of a bladder catheter

c. Wound: Infection; a very high fever in the immediately postoperative period can be indicative of a clostridial or group A streptococcal soft-tissue necrotizing infection. Examine the wound for signs of necrosis, including crepitus deep to the epidermis. If necrosis is present, debride the wound to clean edges immediately, and order antibiotics.

d. Walking: Phlebitis, DVT

e. Wonder Drugs: Drug fever (common causes are listed in Fever).

f. Woman: Endometritis, mastitis (common only in postpartum period)

2. Elevated WBC Count: Commonly elevated secondary to catecholamine discharge after stress such as surgery or childbirth. However, very low white counts can also be a sign of overwhelming sepsis or immunocompromise.

3. Temperatures of 103 105 F (39.4 40.5 C) In adults, think of lung or kidney infections, or bacteremia.

4. Lethargy, Combativeness, Inappropriate Behavior: Strongly consider doing an LP to rule out meningitis.

5. Elderly Patients: Can be extremely ill without many of the typical manifestations; they may be hypothermic or may deny any tenderness that could point toward an obvious source. On laboratory examination, elderly patients may not mount the same WBC response to an infection that an otherwise young, healthy individual might. Be aggressive in identifying the cause.

6. Infants and Children: Have normally elevated baseline temperatures (up to 3 mo, 99.4 F [37.4 C]; 1 y, 99.7 F [37.6 C]; 3 y, 99.0 F [37.2 C]).

7. Immunosuppressed patients after solid organ transplantation or patients being treated with high doses of steroids may not be able to mount a fever in response to stress or infection. In this patient population, normal temperatures do not exclude infection.

Gastrointestinal Intubation

Indications

• GI decompression: ileus, obstruction, pancreatitis associated with emesis, postoperative period
• Lavage of the stomach with GI bleeding or drug overdose
• Prevention of aspiration in an obtunded patient
• Feeding a patient who is unable to swallow

Materials

• GI tube of choice (see Types of GI Tubes)
• Lubricant jelly
• Catheter tip syringe
• Glass of water with a straw, stethoscope

Types of GI Tubes

1. Nasogastric Tubes

a. Levin: A tube with a single lumen, a perforated tip, and side holes for the aspiration of gastric contents. Connect the tube to an intermittent suction device to prevent the stomach lining from obstructing the lumen. Sometimes it is necessary to cut off the tip to allow aspiration of larger pills and tablets. The size varies from 10 to 18 Fr (1 Fr unit = mm in diameter, see Figure 13 1).

b. Salem Sump: A double-lumen tube; the smaller tube is an air intake vent so that continuous suction can be applied. The best tube for irrigation and lavage because it will not collapse on itself. If a Salem sump tube stops working even after it is repositioned, often a "shot" of air from a catheter-tipped syringe in the air vent will clear the tube. Both the Salem sump and Levin tubes have radiopaque markings. In general, for suspected obstruction place an 18-Fr tube; smaller diameter tubes are less effective at suctioning and become clogged more easily than wider tubes.

2. Intestinal Decompression Tubes ("long intestinal tubes"). These tubes have largely fallen out of favor because of a lack of data supporting their use in intestinal obstruction.

a. Cantor Tube: A long single-lumen tube with a rubber balloon at the tip. The balloon is partially filled with mercury (5 7 mL through a tangentially directed 21-gauge needle, then the air is aspirated), which allows it to gravitate into the small bowel with the aid of peristalsis. Used for decompression of distal bowel obstruction.

b. Miller Abbott Tube: A long double-lumen tube with a rubber balloon at the tip. One lumen is used for aspiration; the other connects to the balloon. After the tube is in the stomach, inflate the balloon with 5 10 mL of air, inject 2 3 mL of mercury into the balloon, and then aspirate the air. Functioning and indications are essentially the same as for the Cantor tube. Do not tape these intestinal tubes to the patient's nose, or the tube will not descend. The progress of the tube can be followed on radiographs.

3. Feeding Tubes. Although any NG tube can be used as a feeding tube, it is preferable to place a specially designed nasoduodenal feeding tube. These tubes are of smaller diameter (usually 8 Fr) and are more pliable and comfortable for the patient. Weighted tips tend to travel into the duodenum, which may help prevent regurgitation and aspiration. Most feeding tubes are supplied with stylets that facilitate positioning, especially if fluoroscopic guidance is needed. Always verify the position of the feeding tube with a radiograph before starting tube feeding. Commonly used tubes include mercury-weighted varieties (Keogh tube, Duo-Tube, Dobbhoff), tungsten-weighted (Vivonex tube), and unweighted pediatric feeding tubes. Take great care with these tubes because complications such as tracheobronchial intubation can easily occur.

4. Miscellaneous Gastrointestinal Tubes

a. Sengstaken Blakemore Tube: A triple-lumen tube used exclusively for the control of bleeding esophageal varices by tamponade. One lumen is for gastric aspiration, one is for the gastric balloon, and the third is for the esophageal balloon. Other types include the Linton and Minnesota tubes. These tubes are no longer routinely used; quick access to endoscopy allows for more efficient treatment under direct visualization.

b. Ewald Tube: An orogastric tube used almost exclusively for gastric evacuation of blood or drug overdose. The tube is usually double lumen and large diameter (18 36 Fr).

c. Dennis, Baker, Leonard Tubes: Used for intraoperative decompression of the bowel and are manually passed into the bowel at the time of laparotomy.

Procedure (for Nasogastric and Feeding Tubes)

1. Inform the patient of the nature of the procedure and encourage cooperation if the patient is able. Choose the nasal passage that appears most open. The patient should sit up if able. Before beginning the procedure, ask the patient about recent facial or skull base fractures or trauma and recent transphenoidal and other neurosurgical or otolaryngologic procedures.

2. Lubricate the distal 3 4 in (8 10 cm) of the tube with a water-soluble jelly (K-Y Jelly or viscous lidocaine), and insert the tube gently along the floor of the nasal passageway. Maintain gentle pressure that will allow the tube to pass into the nasopharynx. Have the patient flex the neck slightly from neutral. Inform the patient that it may be slightly uncomfortable and to avoid gasping, which can cause inadvertent tracheal intubation.

3. When the patient can feel the tube in the back of the throat, ask him or her to swallow small amounts of water through a straw as you advance the tube 2 3 in (5 8 cm) at a time.

4. To be sure that the tube is in the stomach, aspirate gastric contents or blow air into the tube with a catheter-tipped syringe and listen over the stomach with a stethoscope for a "pop" or "gurgle." To prevent accidental bronchial instillation of tube feedings, verify the position of feeding tubes with radiography before starting feedings. Most Salem sump tubes have four black markers at the end of the tube. Proper placement in most adults is achieved when two of the markers are inside the patient and two are outside.

5. NG tubes are attached either to low continuous wall suction (Salem sump tubes with a vent) or to intermittent suction (Levin tubes); the latter allows the tube to fall away from the gastric wall between suction cycles.

6. Feeding and pediatric feeding tubes in adults are more difficult to insert because they are more flexible. Many are provided with stylets that make passage easier. Feeding tubes are best placed into the duodenum or jejunum to decrease the risk of aspiration. Administer 10 mg of metoclopramide (Reglan) IV 10 min before insertion to aid in placing the tube into the duodenum. Once the feeding tube is in the stomach, place the bell of the stethoscope on the right side of the middle portion of the patient's abdomen. While advancing the tube, inject air to confirm progression of the tube to the right, toward the duodenum. If the sound of the air becomes fainter, the tube is probably curling in the stomach. Pass the tube until a slight resistance is felt, heralding the presence of the tip of the tube at the pylorus. Holding constant pressure and slowly injecting water through the tube is often rewarded with a "give," which signifies passage through the pylorus. The tube often can be advanced far into the duodenum with this method. The duodenum usually provides constant resistance that will give with slow injection of water. Placing the patient in the right lateral decubitus position may help the tube enter the duodenum. Always confirm the location of the tube with an abdominal radiograph.

7. Tape the tube securely in place, but do not allow it to apply pressure to the ala of the nose. (Note: Intestinal decompression tubes should not be taped because they are allowed to pass through the intestine.) Patients have been disfigured because of ischemic necrosis of the nose caused by a poorly positioned NG tube.

8. Be extremely careful with sedated and intubated patients because it is possible to introduce these small feeding tubes past the ET into the trachea and furthermore into the distal bronchial tree, causing pneumothorax. If you meet any resistance, stop immediately and obtain a CXR to assess placement.

Complications

• Inadvertent passage into the trachea can provoke coughing or gagging in the patient.
• Aspiration
• If the patient is unable to cooperate, the tube often becomes coiled in the oral cavity.
• The tube is irritating and may cause a small amount of bleeding in the mucosa of the nose, pharynx, or stomach. The drying and irritation can be lessened with throat lozenges or antiseptic spray.
• Intracranial passage in a patient with a basilar skull fracture
• Esophageal perforation
• Esophageal reflux caused by tube-induced incompetence of the distal esophageal sphincter
• Sinusitis from edema of the nasal passages that blocks drainage from the nasal sinuses

Heelstick and Fingerstick (Capillary Blood Sampling)

Indication

• Collection of blood samples from infants
• Fingerstick also can be used for small samples in older children and adults

Materials

• Alcohol swabs
• Lancet (BD QuikHeel lancet, BD Genie Lancet for fingersticks that require high volume of blood. BD Genie needle lancet for glucose determinations)
• Collection container: capillary tube, BD Microtainer tube (with Micro-Guard closure) or Caraway tubes
• Clay or other capillary tube sealer

Heelstick Technique

To avoid the risk of repeated venous punctures, especially in infants, assays have been developed that rely on small volumes of blood. Although called "heelstick" and "fingerstick," any highly vascularized capillary bed can be used (finger pad, earlobe, and great toe).

1. The heel can be warmed for 5 10 min by wrapping it in a warm washcloth. Wipe the area with an alcohol swab. Use Figure 13 11A to choose the site for the puncture; use of these sites helps decrease risk of osteomyelitis.

2. Use a lancet, and make a quick, deep puncture so that blood flows freely (see Figure 13 11A). An automated safety lancet (BD QuikHeel Lancet in neonatal and infant sizes) for heelstick is held over the site at a 90-degree angle to the foot (Figure 13 11B). A button activates the blade, after which the blade retracts into its casing.

3. Wipe off the first drop of blood. Gently squeeze the heel and touch a collection tube to the drop of blood. The tube should fill by capillary action and is sealed.

4. Labs can make determinations on small samples from pediatric patients. A Caraway tube can hold 0.3 mL of blood. One to three Caraway tubes can be used for most routine tests. For a capillary blood gas, the blood is usually transferred to a 1-mL heparinized syringe and placed on ice. BD Microtainer tubes with Microgard closure are available in color-coded styles for specific blood determinations similar to those of larger Vacutainer tubes (See Table 13 8).

5. Samples should flow freely enough that the specimen can be collected in less than 2 min. Longer time periods may be affected by microclotting of the sample.

6. Wrap the site with 4 x 4 gauze squares, or apply an adhesive bandage.

Figure 13 11.

A. Preferred sites and technique of heelstick in an infant. (Reprinted, with permission, from: Gomella TL [ed] Neonatology: Basic Management, On-Call Problems, Diseases, Drugs, 5th ed. McGraw-Hill, 2004.) B. Use of an automated lancet (BD QuikHeel Lancet [BD Biosciences]) for heelstick in an infant. The device is held 90 degrees to the axis of the foot and activated.

Fingerstick Technique

1. Clean the puncture site with alcohol, and allow to air dry.

2. Remove the protective cap from the safety lancet (BD Genie lancet) and position the lancet over pad of finger.

3. Press the white activation button with your thumb. Discard device.

4. Gently massage from base of finger to puncture site to collect sample. Holding the patient's hand below level of elbow will enhance blood flow. For glucose determinations with a device such as the Genie needle lancet, only a drop of blood is needed to apply to the reagent strip for glucose determination. A lancet style device is not necessary because of the small amount of blood needed.

5. Follow steps 3 6 as for heelstick.

Complications

Cellulitis at site, osteomyelitis for heelstick in infants

Internal Fetal Scalp Monitoring

Indication

• Accurate assessment of fetal heart rate (FHR) patterns during labor to screen for possible fetal distress

Contraindications

• Presence of placenta previa
• Lack of ability to identify the portion of the fetal body where device application is being considered
• Active herpes, active hepatitis, or HIV in the mother

Materials

• Fetal scalp monitoring electrode
• Sterile vaginal lubricant or povidone iodine spray
• Spiral electrode
• Leg plate, fetal monitor

Procedure

1. Position the woman in the dorsal lithotomy position (knees flexed and abducted), and perform an aseptic perineal prep with sterile vaginal lubricant or povidone iodine spray.

2. Perform a manual vaginal exam, and clearly identify the fetal presenting part. The membranes must be ruptured before attachment of the spiral electrode.

3. Remove the spiral electrode from the sterile package and place the guide tube firmly against the fetal presenting part. Electrode should not be applied to fetal face, fontanels, or genitalia.

4. Advance the drive tube and electrode until the electrode contacts the presenting part. Maintaining pressure on the guide tube and drive tube, rotate the drive tube clockwise until mild resistance is met (usually one turn).

5. Press together the arms on the drive tube grip, which releases the locking device. Carefully slide the drive and guide tubes off the electrode wires while holding the locking device open.

6. Attach the spiral electrode wires to the color-coded leg plate, which is then connected to the electronic fetal monitor.

7. Clean the area of electrode placement on the baby's scalp after delivery.

Complications

• Fetal or maternal hemorrhage, fetal infection (usually scalp abscess at the site of insertion)
• Malpositioning of the monitor on the maternal cervix making it impossible to obtain FHR. Test placement by gently pulling on the catheter; if the woman feels discomfort, the electrode may be inappropriately placed.

Interpretation

Normal FHR is 120 160 beats/min.

Accelerations: Increases in FHR can be associated with fetal distress (usually in association with late decelerations) but are almost always a sign of fetal well-being.

Decelerations: Transient decreases in FHR are related to a uterine contraction and are of three types:

1. Early Deceleration: In normal labor, slowing of FHR associated with the onset of a contraction. FHR promptly returns to normal after the contraction is over. Usually due to head compression, occasionally by cord compression.

2. Late Deceleration: Slowing of the FHR that occurs after the uterine contraction starts and the rate does not return to normal until well after the contraction is over. This pattern is often associated with uteroplacental insufficiency (fetal acidosis or hypoxia).

3. Variable Deceleration: Irregular pattern of deceleration unassociated with contractions; caused by cord compression.

Other Patterns

1. Beat-to-Beat Variability: Small fluctuations in FHR 5 15 beats/min over the baseline FHR usually associated with fetal well-being

2. Bradycardia: Associated with maternal and fetal hypoxia, fetal heart lesions including heart block. If bradycardia persists, evaluate with scalp pH.

3. Tachycardia: Often an early sign of fetal distress, seen with febrile illnesses, hypoxia, fetal thyrotoxicosis

4. Sinusoidal Pattern: Can be drug-induced and is seen occasionally with severe fetal anemia

Injection Techniques

Indications

• Intradermal: Most commonly used for skin testing (eg, PPD)
• Subcutaneous: Useful for low-volume medications such as insulin, heparin, and some vaccines
• Intramuscular: Administration of parenteral medications that cannot be absorbed from the SQ layer or of high volume ( 10 mL)

Contraindications

• Allergy to any components of the injectate
• Active infection or dermatitis at the injection site
• Coagulopathy (IM injections)

Procedure

Intradermal:

(See Skin Testing.)

Subcutaneous

1. Deposit the drug within the fat but above the muscle. With careful placement of the injection, nerve injury is rarely a danger.

2. Choose a site free of scarring and active infection. Injection sites include the outer surface of the upper arm, anterior surface of the thigh, and lower abdominal wall. For repeated injections (eg, for diabetic patients), rotate the sites.

3. 25 27 gauge 1 in (2 2.5 cm) needles are most commonly used; volume of medication must not exceed 5 mL. Draw up the medication, making certain to expel any air bubbles.

4. Clean the site with an alcohol swab. Bunch up the skin with your thumb and forefinger so that the SQ tissue is off the underlying muscle.

5. Warn the patient that there will be "pinch" or "sting," and insert the needle firmly and rapidly at a 45-degree angle until a sudden release signifies penetration of the dermis.

6. Release the skin, aspirate to make certain a blood vessel has not been entered, and inject slowly.

7. Withdraw the needle and apply gentle pressure. Activate the automatic needle shield (eg, BD SafetyGlide shielding hypodermic needle) and discard the needle. A dressing is not usually necessary. Apply pressure longer if there is bleeding from the site.

Intramuscular

1. Common sites include the deltoid, gluteus, and vastus lateralis.

• Deltoid Muscle: The safe zone includes only the main body of the deltoid muscle lying lateral and a few centimeters beneath the acromion. There is low risk of radial nerve injury unless the needle strays into the middle or lower third of the arm.
• Gluteus Muscles: This muscle is the preferred site for children > 2 y and adults. Draw an imaginary line from the femoral head to the posterior superior iliac spine. This site (upper outer quadrant of the buttocks) is safe for injections because it is away from the sciatic nerve and superior gluteal artery.
• Vastus Lateralis Muscle (anterior thigh): A very safe site for all patients and the site of choice for infants. The only disadvantage of this site is that the firm fascia lata overlying the muscle can make needle insertion somewhat more painful.

2. A 22-gauge, 1 in (4 cm) needle is acceptable for most IM injections. Remove air bubbles from the syringe and needle. Wipe the skin with alcohol.

3. Gently stretch the skin to one side and warn the patient of a sting. Penetrate the skin at a 90-degree angle, and advance the needle approximately 1 in (2.5 cm) into the muscle. (Obese patients may require deeper penetration with a longer needle.)

4. Aspirate to make sure a blood vessel has not been entered. Administer the medication. Gently massage the site with an alcohol swab or gauze to promote absorption.

Complications

• Nerve and arterial injury
• Abscesses (sterile or septic). Use good technique and rotate injection sites.
• Bleeding can usually be controlled with pressure.

Intrauterine Pressure Monitoring

Indication

• Accurate assessment of uterine contraction during labor

Contraindication

• Placenta previa

Materials

• Pressure catheter and introducer
• Transducer connected to fetal monitor
• Sterile gloves, vaginal lubricant, povidone iodine spray
• 10-mL syringe, 30 mL sterile water

Procedure

1. Prime the transducer with sterile water.

2. Position the patient in the dorsal lithotomy position (knees flexed and abducted), and perform an aseptic perineal prep with sterile vaginal lubricant or povidone iodine spray.

3. Perform a manual vaginal exam, and clearly identify the fetal presenting part. The patient must be in labor with a cervix dilated at least 1 2 cm, and the membranes must be ruptured before insertion of the catheter.

4. Remove the catheter from the sterile package, and place the guide tube through your fingers around the presenting part into the uterine cavity.

5. Prime the catheter with sterile water and thread through the guide tube.

6. Attach the distal catheter to the transducer and zero to air.

Complications

Infection, placental perforation if the placenta is low lying

IV Techniques

Indication

• IV access for administration of fluids, blood, or medications (other techniques include Central Venous Catheterization, and Peripheral Insertion of Central Catheter (PICC).)

Materials

• IV fluid
• Connecting tubing
• Tourniquet
• Alcohol swab
• IV cannulas (a catheter over a needle [eg, BD Insyte Autoguard shielded IV catheter, BD Angiocath Autoguard shielded IV catheter] or a butterfly-style needle)
• Antiseptic ointment, dressing, and tape

Procedure

1. It helps to rip the tape into strips, attach the IV tubing to the solution, and flush the air out of the tubing before you begin.

2. The upper, nondominant extremity is the site of choice for an IV, unless the patient is being considered for placement of permanent hemodialysis access. In this instance, the upper nondominant extremity should be "saved" as the access site for hemodialysis. If the patient has previously undergone axillary lymph node dissection (eg, some breast cancer operations), start the IV on the side opposite the surgical site. Choose a distal vein (dorsum of the hand) so that if the vein is lost, you can reposition the IV more proximally. Figure 13 12 shows common upper extremity veins; avoid veins that cross a joint space. Also avoid the leg because of the increased risk of thrombophlebitis.

3. Apply a tourniquet above the proposed IV site. Use the techniques described in Venipuncture to help expose the vein. Carefully clean the site with an alcohol or povidone iodine swab. If a large-bore IV needle is to be used (16- or 14-gauge), local anesthesia (lidocaine injected with a 25-gauge needle) is helpful.

4. Stabilize the vein distally with the thumb of your free hand. Using the catheter-over-needle assembly, either enter the vein directly or enter the skin alongside the vein first and then stick the vein along the side at about a 20-degree angle. Direct-entry and side-entry IV techniques are illustrated in Figures 13 13 and 13 14. Once the vein is punctured, blood should appear in the "flash chamber." Lower the needle assembly. The next steps vary if you are using a standard catheter-over-needle device or a self-shielding device:

a. Standard Catheter-over-Needle (Figure 13 13A). Advance a few more millimeters to be sure that both the needle and the tip of the catheter have entered the vein. Thread the catheter into the vein while maintaining traction on the skin. Remove the tourniquet, compress the vein, and stabilize the catheter hub. Connect the IV fluid.

b. Self Shielding Device. After seeing the flashback, lower the catheter assembly to almost parallel to the skin. Advance the entire unit before attempting to thread the catheter. Thread the catheter into the vein while maintaining traction. Release the tourniquet and apply pressure beyond the catheter tip, making sure to maintain digital pressure beyond the catheter tip (Figure 13 13B). Press the white button, and the needle retracts into a shield. Connect the IV line to the catheter.

5. With the IV fluid running, observe the site for signs of induration and swelling, which indicate improper placement or damage to the vein. (See Chapter 9 for choosing IV fluids and how to determine infusion rates.)

6. Tape the IV securely in place; apply a drop of povidone iodine or antibiotic ointment and apply a sterile dressing. Ideally, the dressing should be changed every 24 48 h to help reduce the likelihood of infection. Arm boards are also useful to help maintain an IV site.

7. Never reinsert the needle into the catheter. Doing so can cause shearing in the catheter.

8. A butterfly, or scalp vein needle can sometimes be used (see Figure 13 14). This small metal needle has plastic "wings" on the side. It is very useful in infants (who often have poor peripheral veins but prominent scalp veins), children, and in adults who have small, fragile veins.

9. Troubleshooting difficult IV placement

• If the veins are deep and difficult to locate, a 3- to 5-mL syringe can be mounted on the catheter assembly. Determine proper positioning inside the vein by aspirating blood. If blood specimens are needed for a patient who also needs an IV, use this technique to start the IV and collect samples at the same time.
• A Whaid maneuver can be attempted (J Emerg Nurs 1993;19:186). Spend about 1 min using both hands to "milk" blood from the arm toward the forearm. While holding the arm compressed with both hands, place a tourniquet above the elbow. Milk the blood from the fingers to the forearm for 3 5 min. When a vein becomes prominent, wrap your hand around the patient's wrist and place the IV.
• If no extremity vein can be found, try the external jugular vein. Placing the patient in the head-down position (deep Trendelenburg) can help distend the vein.
• If all these maneuvers fail, insert a central venous line insertion (Central Venous Catheterization).

Figure 13 12.

Principal veins of the arm used for IV access and in venipuncture. The pattern can be highly variable. (Reprinted, with permission, from: Stillman RM [ed] Surgery, Diagnosis, and Therapy, Appleton & Lange, Norwalk, CT, 1989.)

Figure 13 13.

A. Technique for insertion of a standard catherter-over-needle device for IV access. Stabilize the vein with gentle traction. Enter the vein; when a flash of blood is observed in the chamber, advance the entire assembly slightly to ensure that the catheter tip is in the lumen of the vein. Advance the catheter off the end of the needle, and remove the needle. B. When using a device such as an Angiocath Autoguard (BD Biosciences), before pressing the autoshield button, apply digital pressure as shown to stabilize the catheter and to prevent blood from escaping after the needle is removed. Activate the self-shielding needle by pushing the white button on the needle device.

Figure 13 14.

Example of a butterfly needle assembly and the two different techniques of entering a vein for IV access. A. Direct puncture. B. Side entry. (Reprinted, with permission, from: Gomella TL [ed] Neonatology: Basic Management, On-Call Problems, Diseases, Drugs, 5th ed. McGraw-Hill, 2004.)

Lumbar Puncture

Indications

• Diagnosis: Analysis of CSF for conditions such as meningitis, encephalitis, Guillain Barr syndrome, and staging work-up for lymphoma
• Measurement of CSF pressure or its changes with various maneuvers (eg, Valsalva)
• Injection of agents eg, contrast media for myelography, antitumor drugs, analgesics, antibiotics

Contraindications

• Increased intracranial pressure (papilledema, mass lesion)
• Infection near the puncture site
• Planned myelography or pneumoencephalography
• Coagulation disorders

Materials

• Sterile, disposable LP kit

  or

• Minor procedure tray (see Table 13 1)
• Spinal needles (21-gauge for adults, 22-gauge for children)

Background

The objective of LP is to obtain a sample of CSF from the subarachnoid space. Specifically, during LP the fluid is obtained from the lumbar cistern, the CSF located between the termination of the spinal cord (conus medullaris) and the termination of the dura mater at the coccygeal ligament. The cistern is surrounded by the subarachnoid membrane and the overlying dura. Located within the cistern are the filum terminale and the nerve roots of the cauda equina. When LP is done, the main body of the spinal cord is avoided, and the nerve roots of the cauda are simply pushed out of the way by the needle. The termination of the spinal cord in adults is usually between L1 and L2, and in pediatric patients between L2 and L3. The safest site for LP is the interspace between L4 and L5. An imaginary line drawn between the iliac crests (the supracristal plane) intersects the spine at either the L4 spinous process or the L4 L5 interspace. A spinal needle introduced between the spinous processes of L4 and L5 penetrates the layers in the following order: skin, supraspinous ligament, interspinous ligament, ligamentum flavum, epidural space (contains loose areolar tissue, fat, and blood vessels), dura, "potential space," subarachnoid membrane, and subarachnoid space (lumbar cistern) (Figure 13 15).

Figure 13 15.

Basic anatomy for lumbar puncture.

Procedure

1. Examine the fundus for evidence of papilledema, and review the CT or MRI of the head if available. Discuss the relative safety and lack of discomfort to the patient to dispel any myths. Some clinicians prefer to call the procedure "subarachnoid analysis" rather than a spinal tap. As long as the procedure and the risks are outlined, most patients agree to the procedure. Have the patient sign an informed consent form.

2. Place the patient in the lateral decubitus position close to the edge of the bed or table. The patient (held by an assistant, if possible) should be positioned with knees pulled up toward stomach and head flexed onto chest (Figure 13 16). This position enhances flexion of the vertebral spine and widens the interspaces between the spinous processes. Place a pillow beneath the patient's side to prevent sagging and ensure alignment of the spinal column. If the patient is obese or has arthritis or scoliosis, the sitting position, leaning forward, may be preferred.

3. Palpate the supracristal plane (see Background) and carefully determine the location of the L4 L5 interspace.

4. Open the kit, put on sterile gloves, and prep the area with povidone iodine solution in a circular manner and covering several interspaces. Drape the patient.

5. With a 25-gauge needle and lidocaine, raise a skin wheal over the L4 L5 interspace. Anesthetize the deeper structures using a 22-gauge needle.

6. Examine the spinal needle (20- or 22-gauge) with stylet for defects and then insert it into the skin wheal and into the spinous ligament. Hold the needle between your index and middle fingers with your thumb holding the stylet in place. Direct the needle cephalad at a 30- to 45-degree angle in the midline and parallel to the bed (see Figure 13 16).

7. Advance the needle through the major structures and pop into the subarachnoid space through the dura. An experienced operator can feel these layers, but an inexperienced one may need to periodically remove the stylet to look for return of fluid. It is important to always replace the stylet before advancing the spinal needle. The needle may be withdrawn, however, with the stylet removed. This technique may be useful if the needle has passed through the back wall of the canal. Direct the bevel of the needle parallel to the long axis of the body so that the dural fibers are separated rather than sheared. This method helps cut down on "spinal headaches."

8. If no fluid returns, it is sometimes helpful to rotate the needle slightly. If still no fluid appears, and you believe the needle is within the subarachnoid space, inject 1 mL of air; it is not uncommon for a piece of tissue to clog the needle. Never inject saline solution or distilled water. If no air returns and if spinal fluid cannot be aspirated, the bevel of the needle is probably in the epidural space; advance it with the stylet in place.

9. When fluid returns, attach a manometer and stopcock and measure the pressure. Normal opening pressure is 70 180 mm water in the lateral position. Increased pressure may be due to a tense patient, CHF, ascites, subarachnoid hemorrhage, infection, or a space-occupying lesion. Decreased pressure may be due to CSF leak, needle position, or obstructed flow (you may need to leave the needle in for a myelogram because if it is moved, the subarachnoid space may be lost).

10. Collect 0.5- to 2.0-mL samples in serial, labeled containers. Send them to the lab in this order:

• First tube for bacteriology: Gram stain, routine C&S, AFB, and fungal cultures and stains.
• Second tube for glucose and protein: In addition, if MS is suspected, order electrophoresis to detect oligoclonal banding and assay for myelin basic protein.
• Third tube for cell count: CBC with diff
• Fourth tube for special studies as clinically indicated: VDRL (neurosyphilis), CIEP (counter-immunoelectrophoresis) for bacterial antigens such as Haemophilus influenzae, Streptococcus pneumoniae, Neisseria meningitidis, PCR assay for tuberculous meningitis and herpes simplex encephalitis (allows rapid diagnosis). If Cryptococcus neoformans is suspected (most common cause of meningitis in AIDS patients), India ink preparation and cryptococcal antigen (latex agglutination test).
• Note: Some clinicians prefer to send the first and last tubes for CBC because this procedure allows better differentiation between subarachnoid hemorrhage and a traumatic tap. In a traumatic tap, the number of RBCs in the first tube should be much higher than in the last tube. In subarachnoid hemorrhage, the cell counts should be equal, and xanthochromia of the fluid should be present, indicating the presence of old blood.

11. Withdraw the needle, and place a dry, sterile dressing over the site.

12.Instruct the patient to remain lying down for 6 12 h, and encourage increased fluid intake to help prevent "spinal headaches."

Figure 13 16.

For lumbar puncture, place the patient in the lateral decubitus position, and locate the L4 L5 interspace. Control the spinal needle with two hands, and enter the subarachnoid space.

Interpret the results using Table 13 4.

Table 13 4 Differential Diagnosis of Cerebrospinal Fluid

Condition	Color	Opening Pressure (mm H2O)	Protein (mL/100 mL)	Glucose (mg/100 mL)	Cells (#/mm3)
NORMAL
Adult	Clear	70 180	15 45	45 80	0 5 lymphocytes
Newborn	Clear	70 180	20 120	2/3 serum	40 60 lymphocytes
INFECTIOUS
Viral infection ("aseptic meningitis")	Clear or opalescent	Normal or slightly increased	Normal or slightly increased	Normal	10 500 lymphocytes PMN early
Bacterial infection	Opalescent yellow, may clot	Increased	50 10,000	Decreased, usually <20	25 10,000 PMN
Granulomatous infection (TB, fungal)	Clear or opalescent	Often increased	Increased, but usually <500	Decreased, usually <20 40	10 500 lymphocytes
NEUROLOGIC
Guillain Barr syndrome	Clear or cloudy	Normal	Markedly increased	Normal	Normal or increased lymphocytes
Multiple sclerosis	Clear	Normal	Normal or increased	Normal	0 20 lymphocytes
Pseudotumor cerebri	Clear	Increased	Normal	Normal	Normal
MISCELLANEOUS
Neoplasm	Clear or xanthochromic	Increased	Normal or increased	Normal or decreased	Normal or increased lymphocytes
Traumatic tap	Bloody, no xanthochromia	Normal	Normal	Increased	RBC = peripheral blood; fewer RBC in tube 4 than in tube 1
Subarachnoid hemorrhage	Bloody or xanthochromic after 2 8 h	Usually increased	Increased	Normal	WBC/RBC ratio same as blood, RBC in tube 1 = tube 4

WBC = white blood cells; RBC = red blood cells; PMN = polymorphonuclear neutrophils.

Complications

• Spinal headache: The most common complication (about 20%), appears within the first 24 h after LP. It is relieved when the patient lies down and is aggravated when the patient sits up. Spinal headache is characterized by severe throbbing pain in the occipital region and can last a week. It is thought to be caused by intracranial traction caused by acute volume depletion of CSF and by persistent leakage from the puncture site. To help prevent spinal headache, keep the patient recumbent for 6 12 h, encourage intake of fluids (especially caffeinated drinks such as coffee, tea, and soft drinks), use the smallest needle possible, and keep the bevel of the needle parallel to the long axis of the body to help prevent persistent CSF leak. If the headache persists, a blood patch (peripheral blood injected into the epidural space, usually performed by anesthesia service) may be needed to seal the leak.
• Trauma to nerve roots or to the conus medullaris: Much less frequent (some anatomic variation does exist, but it is very rare for the cord to end below L3). If the patient suddenly complains of paresthesia (numbness or shooting pain in the legs), stop the procedure.
• Herniation of either the cerebellum or the medulla: Occurs rarely during or after spinal tap, usually in a patient with increased intracranial pressure. This complication can often be reversed medically if it is recognized early.
• Meningitis
• Bleeding in the subarachnoid or subdural space can occur with resulting paralysis, especially if the patient is receiving anticoagulants or has severe liver disease with coagulopathy.

Orthostatic Blood Pressure Measurement

Indication

• Assessment of volume depletion

Materials

• BP cuff and stethoscope

Procedure

1. Changes in BP and pulse when a patient moves from supine to the upright position are very sensitive guides for detecting early volume depletion. Even before a person becomes overtly tachycardic or hypotensive because of volume loss, the demonstration of orthostatic hypotension aids in the diagnosis.

2. Have the patient assume a supine position for 5 10 min. Determine the BP and pulse.

3. Have the patient stand up. If the patient is unable to stand, have the patient sit at the bedside with legs dangling.

4. After about 1 min, measure BP and pulse again.

5. A drop in systolic BP greater than 10 mm Hg or an increase in pulse rate greater than 20 beats/min (16 beats/min in the elderly) suggests volume depletion. A change in heart rate is more sensitive and occurs with a lesser degree of volume depletion. Other causes of a drop in BP with body position change (usually without an increase in heart rate) include peripheral neuropathy, surgical sympathectomy, diabetes, and medications (prazosin, hydralazine, or reserpine).

Pelvic Examination

Indications

• Physical examination of female patients
• Diagnosis of diseases and conditions of the female genital tract

Materials

• Sterile gloves
• Vaginal speculum and lubricant
• Slides, fixative (eg, Pap smear aerosol spray), cotton swabs, endocervical brush and cervical spatula prepared for a Pap smear

Materials for Other Diagnostic Tests

• Culture media to test for gonorrhea, Chlamydia, herpes
• Sterile cotton swabs
• Plain glass slides
• KOH
• NS solutions, as needed

Procedure

1. Perform the pelvic exam in conditions that are as comfortable as possible for both patient and physician. Either the physician or the assistant must be a woman. Drape the patient appropriately and help her place her feet in the stirrups on the examining table. Prepare a low stool, a good light source, and all needed supplies before starting the exam. In unusual situations examinations are conducted on a gurney or bed; raise the patient's buttocks on one or two pillows to elevate the perineum off the mattress.

2. Inform the patient of each movement in advance. Glove hands before proceeding.

3. General inspection

a. Observe the skin of the perineum for swelling, ulcers, condylomata (venereal warts), and color changes.

b. Separate the labia to examine the clitoris and vestibule. Multiple clear vesicles on an erythematous base on the labia suggest herpes.

c. Observe the urethral meatus for developmental abnormalities, discharge, neoplasm, and abscess of Bartholin glands at the 4 and 8 o'clock positions.

d. Inspect the vaginal orifice for discharge and protrusion of the walls (cystocele, rectocele, urethral prolapse).

e. Note the condition of the hymen.

4. Speculum examination

a. Use a speculum moistened with warm water not with lubricant (lubricant interferes with Pap tests and slide studies). Touch the speculum to the patient's leg to see whether the temperature is comfortable.

b. Because the anterior wall of the vagina is close to the urethra and bladder, do not exert pressure in this area. Place pressure on the posterior surface of the vagina. With the speculum directed at a 45-degree angle to the floor, spread the labia and insert the speculum fully, pressing posteriorly. The cervix should pop into view with some manipulation as the speculum is opened.

c. Inspect the cervix and vagina for color, lacerations, growths, nabothian cysts, and evidence of atrophy.

d. Inspect the cervical os for size, shape, color, and discharge.

e. Inspect the vagina for secretions and obtain specimens for Pap smear, other smear, or culture (see tests for vaginal infections and Pap smear in step 7).

f. Inspect the vaginal wall; rotate the speculum as you draw it out to see the entire canal. Use caution when removing the speculum (especially it if is metal) because it can close quickly if not held open while being withdrawn and can trap vaginal mucosa.

5. Bimanual examination

a. Stand up for this part of the exam. Use whichever hand is comfortable to do the internal vaginal exam. Remove the glove from the hand used to examine the abdomen.

b. Place lubricant on the first and second gloved fingers, and keeping pressure on the posterior fornix, introduce the fingers into the vagina.

c. Palpate the tissue at the 5 and 7 o'clock positions between the first and second fingers and the thumb to rule out any abnormality of the Bartholin glands. Likewise, palpate the urethra and paraurethral (Skene) glands.

d. Place the examining fingers on the posterior wall of the vagina to further open the introitus. Ask the patient to bear down. Look for evidence of prolapse, rectocele, and cystocele.

e. Palpate the cervix. Note the size, shape, consistency, and motility and test for tenderness ("chandelier" sign) and cervical motion tenderness, which is suggestive of PID or ruptured ectopic pregnancy.

f. With your fingers in the vagina posterior to the cervix and your hand on the abdomen placed just above the symphysis, force the corpus of the uterus between the two examining hands. Note size, shape, consistency, position, and motility.

g. Move the fingers in the vagina to one or the other fornix, and place the hand on the abdomen in a more lateral position to bring the adnexal areas under examination. Palpate the ovaries, if possible, for masses, consistency, and motility. Unless they are diseased, the fallopian tubes usually are not palpable.

6. Rectovaginal examination

a. Insert your index finger into the vagina, and place the well-lubricated middle finger in the rectum.

b. Palpate the posterior surface of the uterus and the broad ligament for nodularity, tenderness, and masses. Examine the uterosacral and rectovaginal septum. Nodularity may represent endometriosis.

c. It may also be helpful to do a test for occult blood if a stool specimen is available.

7. Papanicolaou (Pap) smear

The Pap smear is helpful in early detection of cervical intraepithelial neoplasia and carcinoma. Endometrial carcinoma is occasionally identified on routine Pap smears. It is recommended that once they reach age 18 or are sexually active, low-risk patients undergo routine Pap smears done every 2 3 y, but only after three annual Pap smears are negative. High-risk patients such as those exposed in utero to DES; patients with HPV infection or history of HIV infection; history of cervical dysplasia or cervical intraepithelial neoplasia; more than two sexual partners in their lifetime; and intercourse before age 20 should undergo an annual Pap smear.

a. With an unlubricated speculum in place, use a wooden cervical spatula to obtain a scraping from the squamocolumnar junction. Rotate the spatula 360 degrees around the external os. Smear on a frosted slide that has the patient's name written on it in pencil. Fix the slide either in a bottle of fixative or with spray fixative. Fix the slide within 10 s, or a drying artifact may occur.

b. Obtain a specimen from the endocervical canal using a cotton swab or endocervical brush and prepare the slide as described in part a.

c. Using a wooden spatula, obtain an additional specimen from the posterolateral vaginal pool of fluid and smear it on a slide.

d. Complete the appropriate lab slips. Forewarn the patient that she may experience spotty vaginal bleeding after the Pap smear.

8. Tests for cervical and vaginal infections

a. GC and Chlamydia culture: Use a sterile cotton swab to obtain a specimen from the endocervical canal and plate it out on Thayer Martin medium for GC. Chlamydia testing varies but can include DNA probe, EIA, or direct fluorescent antibody (DFA) testing.

b. Vaginal saline (wet) prep: Helpful in the diagnosis of Trichomonas vaginalis and bacterial vaginosis. Mix a drop of discharge with a drop of NS on a glass slide and cover it with a coverslip. Observe the slide while it is still warm to see the flagellated, motile trichomonads. Bacterial vaginosis is most often caused by Gardnerella vaginalis and can be diagnosed by the presence of "clue cells," which represent PMNs dotted with the G. vaginalis bacteria; vaginal pH > 4.5; and a fishy amine odor with addition of KOH to the secretions. It is also possible to see these cells by using a hanging drop of saline and a concave slide. Lactobacillus organisms are normally the predominant bacteria in the vagina in the absence of specific infection, and the normal pH is usually < 4.5.

c. Potassium hydroxide prep: If a thick, white, curdy discharge is present, the patient may have Candida albicans (monilial) yeast infection. Prepare a slide with one drop of discharge and one drop of aqueous 10% KOH solution. The KOH dissolves the epithelial cells and debris and facilitates viewing of the hyphae and mycelia of the fungus that causes the infection.

d. Gram stain: Material can easily be stained in the usual manner (Chapter 7, Gran Stain and Common Pathogens). Gram-negative intracellular diplococci (so-called GNIDs) are pathognomonic of N. gonorrhoeae infection. The bacteria most commonly found in Gram stains are large gram-positive rods (lactobacilli), which are normal vaginal flora.

e. Herpes cultures: A routine Pap smear of the cervix or a Pap smear of the herpetic lesion (multiple, clear vesicles on a painful, erythematous base) may show herpes inclusion bodies. Swab the suspicious lesion or the endocervix to obtain a specimen for herpes viral culture.

Pericardiocentesis

Indications

• Emergency treatment of cardiac tamponade
• Diagnosis of cause of pericardial effusion

Contraindications

• Minimal pericardial effusion (< 200 mL)
• Aftermath of CABG because of risk of injury to grafts
• Uncorrected coagulopathy

Materials

• ECG machine
• Prepackaged pericardiocentesis kit or procedure and instrument tray (Table 13 1) with pericardiocentesis needle or 16- to 18-gauge needle 10 cm long

Background

Cardiac tamponade results in decreased cardiac output, increased right atrial filling pressure, and pronounced pulsus paradoxus.

Procedure

1. If time permits, use sterile prep and draping with gown, mask, and gloves.

2. Use a left paraxiphoid or left parasternal approach through the 4th ICS. The paraxiphoid approach is safer, more commonly used, and described here (Figure 13 17).

3. Anesthetize the insertion site with lidocaine. Connect the needle with an alligator clip to the chest lead (brown) on the ECG machine. Attach the limb leads, and monitor the machine.

4. Insert the pericardiocentesis needle just to the left of the xiphoid process and directed upward 45 degrees toward the left shoulder.

5. Aspirate while advancing the needle until the pericardium is punctured and the effusion is tapped. If you feel the ventricular wall, withdraw the needle slightly. If the needle contacts the myocardium, pronounced ST segment elevation will be recorded on the ECG.

6. If pericardiocentesis is performed for cardiac tamponade, removal of as little as 50 mL of fluid dramatically improves BP and decreases right atrial pressure.

7. Blood from a bloody pericardial effusion is usually defibrinated and does not clot, whereas blood from the ventricle does clot.

8. Send fluid for HCT, cell count, or cytology if indicated.

• Serous fluid: Consistent with CHF, bacterial infection, TB, hypoalbuminemia, or viral pericarditis
• Bloody fluid (HCT > 10%): May result from trauma; be iatrogenic; or be due to MI, uremia, coagulopathy, or malignant disease (lymphoma, leukemia, breast, lung most common)

9. If continuous drainage is necessary, use a guidewire to place a 16-gauge IV catheter and connect to a closed drainage system.

Figure 13 17.

Techniques for pericardiocentesis. The paraxiphoid approach is the most frequently used.

Complications

Arrhythmia, ventricular puncture, lung injury

Peripheral Insertion of Central Catheter (PICC)

Indications

• Home infusion of hypertonic or irritating solutions and drugs
• Long-term infusion of medications (antibiotics, chemotherapeutics)
• TPN
• Repeated venous blood sampling

Contraindications

• Infection over placement site
• Inability to identify veins in an arm with a tourniquet in place

Materials

• PICC catheter kit (contains most items necessary, including the Silastic long arm line, eg, Introsyte Autoguard system)
• Tourniquet, sterile gloves, mask, sterile gown, heparin flush, 10-mL syringes

Background

Installation of a PICC allows for central venous access through a peripheral vein. Typically, a long arm catheter is placed into the basilic or cephalic vein, usually with bedside portable ultrasound guidance (see Figure 13 12) and is threaded into the subclavian vein and superior vena cava. PICCs are useful for long-term home infusion therapy. The design of PICC catheters can vary, and the operator should be familiar with the features of the device (attached hub or detachable hub designs). Usually these catheters are placed by specialized PICC nurses at the bedside or by interventional radiologists under fluoroscopic guidance, but it is prudent to be aware of the technique because any trained medical personnel can be called on to place these catheters.

Procedure

1. Explain the procedure to the patient and obtain informed consent. Have the patient sit or lie down with the elbow extended and the arm in a dependent position. The arm should be externally rotated.

2. Using a measuring tape, determine the length of the catheter required. Measure from the extremity vein insertion site to the subclavian vein.

3. Wear mask, gown, protective eyewear, and sterile gloves. Prep and drape the skin in the standard manner. Set up an adjacent sterile working area.

4. Anesthetize the skin at the proposed area of insertion. Apply a tourniquet above the proposed IV site.

5. Trim the catheter to the appropriate length. Most PICC lines have an attached hub, and the distal end of the catheter is cut to the proper length. Flush with heparinized saline.

6. Insert the catheter and introducer needle (usually 14-gauge) into the chosen arm vein as detailed in IV Techniques. Once the catheter is in the vein, push the white button on the Introsyte device to shield the needle. Discard the needle assembly.

7. Place the PICC line in the catheter and advance it (using a forceps if provided by the manufacturer of the kit). Remove the tourniquet and gradually advance the catheter the requisite length. Remove the inner stiffening wire slowly once the catheter has been adequately advanced.

8. Peel away the introducer catheter. Attach the Luer-Lock, and flush the catheter again with heparin solution. Attempt to aspirate blood to verify patency.

9. Attach the provided securing wings, and suture them in place. Apply a sterile dressing over the insertion site.

10. Confirm placement in the central circulation with a CXR. Always document the type of PICC, the length inserted, and the site of its radiologically confirmed placement.

11. If vein cannulation is difficult, a surgical cutdown may be necessary to cannulate the vein. If the catheter will not advance, fluoroscopy may be helpful.

12. Instruct the patient on the maintenance of the PICC. The PICC should be flushed with heparinized saline solution after each use. Dressing changes should be performed at least every 7 d under sterile conditions. Instruct the patient to evaluate the PICC site for signs and symptoms of infection. Also instruct the patient to come to the ER for evaluation if a fever develops.

13. For venous samples, withdraw a specimen of at least the catheter volume (1 3 mL) and discard it. The PICC must always be flushed with heparinized saline solution after each blood draw.

PICC Removal

1. Position the patient's arm at a 90-degree angle to the body. Remove the dressing and gently pull the PICC out.

2. Apply pressure to site for 2 3 min. Always measure the length of the catheter and check previous documentation to ensure that the PICC line has been removed in its entirety. If a piece of a catheter is left behind, an emergency interventional radiology consult is in order.

Complications

Site bleeding, clotted catheter, subclavian thrombosis, infection, broken catheter (leakage or embolization), arrhythmia (catheter inserted too far)

Peritoneal Lavage

Indications

• Diagnostic peritoneal lavage (DPL) is used in the evaluation of intraabdominal trauma (bleeding, perforation) (Note: Spiral CT of the abdomen has largely replaced DPL as an initial screening tool for intraabdominal trauma in the emergency setting.)
• Acute peritoneal dialysis and management of severe pancreatitis.

Contraindications

• No absolute complications. Relative contraindications: multiple abdominal procedures, pregnancy, known retroperitoneal injury (high false-positive rate), cirrhosis, morbid obesity, coagulopathy

Materials

• Prepackaged DPL or peritoneal dialysis tray

Procedure

1. A Foley catheter and an NG or orogastric tube must be in place to decompress the bladder and viscera. Prep the abdomen from above the umbilicus to the pubis.

2. The site of choice is in the midline 1 2 cm below the umbilicus. Avoid the sites of old surgical scars (danger of adherent bowel). If a subumbilical scar or pelvic fracture is present, use a supraumbilical approach.

3. Infiltrate the skin with lidocaine with epinephrine. Incise the skin in the midline vertically, and expose the fascia.

4. Either pick up the fascia and incise it or puncture it with the trocar and peritoneal catheter. Exercise caution to avoid puncturing any organs. Use one hand to hold the catheter near the skin and to control the insertion while using the other hand to apply pressure to the end of the catheter. After the peritoneal cavity is entered, remove the trocar and direct the catheter inferiorly into the pelvis.

5. During a diagnostic lavage, gross blood indicates a positive tap. If no blood is encountered, instill 10 mL/kg (about 1 L in adults) of RL or NS into the abdominal cavity.

6. Gently agitate the abdomen to distribute the fluid; after 5 min drain off as much fluid as possible into a bag on the floor. (Minimum fluid for a valid analysis is 200 mL in an adult.) If the drainage is slow, try instilling additional fluid, carefully repositioning the catheter.

7. Send the fluid for analysis (amylase, bile, bacteria, hematocrit, cell count). Interpret the findings using Table 13 5.

8. Remove the catheter and suture the skin. If the catheter is inserted because of pancreatitis or for peritoneal dialysis, suture the catheter in place.

9. Negative DPL does not exclude retroperitoneal trauma. False-positive DPL can be caused by a pelvic fracture or bleeding induced by the procedure (eg, laceration of an omental vessel).

Table 13 5 Criteria for Evaluation of Peritoneal Lavage Fluid

Positive	>20 mL gross blood on free aspiration (10 mL in children)
	100,000 RBC/mL
	500 WBC/mL (if obtained >3 h after the injury)
	175 units amylase/dL
	Bacteria on Gram stain
	Bile (by inspection or chemical determination of bilirubin content)
	Food particles (microscopic analysis of strained or spun specimen)
Intermediate	Pink fluid on free aspiration
	50,000 100,000 RBC/mL in blunt trauma
	100 500 WBC/mL
	75 175 units amylase/dL
Negative	Clear aspirate
	100 WBC/L
	75 units amylase/dL

Source: Reprinted, with permission, from: Way, L., Doherty GM (eds): Current Surgical Diagnosis and Treatment, 11th ed. McGraw-Hill, 2003.

RBC = red blood cells; WBC = white blood cells.

Complications

Infection, peritonitis, superficial wound infection, bleeding, perforated viscus (bladder, bowel)

Peritoneal (Abdominal) Paracentesis

Indications

• Determining the cause of ascites
• Determining whether intraabdominal bleeding is present or whether a viscus has ruptured (DPL is considered a more accurate test. See Peritoneal Lavage procedure.)
• Therapeutic removal of fluid when distention is pronounced or respiratory distress is associated with it (acute treatment only)

Contraindications

• Abnormal coagulation factors
• Bowel obstruction, pregnancy
• Uncertainty whether distention is caused by peritoneal fluid or due to a cystic structure (usually can be differentiated with ultrasonography)

Materials

• Minor procedure tray (see Table 13 1)
• Catheter-over-needle assembly (Angiocath Autoguard, Insyte Autoguard 18- to 20-gauge with 11/2-in [4 cm] needle)
• 20 60-mL syringe
• Sterile specimen containers

Procedure

Peritoneal paracentesis is surgical puncture of the peritoneal cavity for aspiration of fluid. Ascites is indicated by abdominal distention, shifting dullness, and a palpable fluid wave; generally ultrasonography is used to confirm ascites.

1. Explain the procedure and have the patient sign an informed consent form. Have the patient empty the bladder, or place a Foley catheter if voiding is impossible or if marked changes in mental status are present.

2. The entry site is usually the midline 1 1 in (3 4 cm) below the umbilicus. Avoid old surgical scars because the bowel may be adherent to the abdominal wall. An alternative entry site is the left or right lower quadrant midway between the umbilicus and the anterior superior iliac spine or the patient's flank, depending on the percussion of the fluid wave (Figure 13 18). Avoid the rectus abdominus because of bleeding potential.

3. Prep and drape the area and raise a skin wheal with the lidocaine over the entry site.

4. A Z track technique helps limit persistent leakage of peritoneal fluid after the tap. Manually retract the skin caudally and release traction on the skin when the peritoneum is entered. With the catheter mounted on the syringe, go through the anesthetized area while aspirating. There is resistance as the fascia is entered. When there is free return of fluid, leave the catheter in place, and remove the needle or activate the self-shielding mechanism. Begin to aspirate; reposition the catheter as needed because of abutting bowel.

5. Aspirate the amount of fluid needed for tests (20 30 mL). If the tap is therapeutic, 10 15 L can be safely removed. The removal of a large volume can be facilitated by the use of vacuum container bottles (500 mL 1 L) supplied at most hospitals. Tubing is first connected to the catheter and then to the vacuum container bottles.

6. Apply a sterile 4 x 4 gauze square, and apply pressure with tape. In patients with chronic ascites, a purse-string suture may be placed at the puncture site to minimize ongoing leakage of ascitic fluid from the tap.

7. Depending on the patient's clinical condition, send samples for cell count including differential, total protein, albumin, amylase, LDH, glucose, cytology, and C&S.

Figure 13 18.

Preferred sites for abdominal (peritoneal) paracentesis. Be sure to avoid old surgical scars.

Complications

Peritonitis, perforated viscus (bowel, bladder), hemorrhage, precipitation of hepatic coma if patient has severe liver disease, oliguria, hypotension

Diagnosis of Ascitic Fluid

A differential diagnosis is in Chapter 3, Ascites. The older classification of ascitic fluid as either transudative or exudative is no longer used. The cause of ascites is more likely to be found by determining the serum-to-ascites albumin gradient. See Table 13 6, above, to interpret the results of ascitic fluid analysis.

Table 13 6 Differential Diagnosis of Ascitic Fluid

Albumin Gradient: 

  Serum Alb Ascites Alb = X

    if X > 1.1 g/dL, then portal hypertension

    if X < 1.1 g/dL, then not from portal hypertension

Total Protein: < 1.0 g/dL, high risk of spontaneous bacterial peritonitis 

Cell Count: Absolute neutrophil count > 250/L, presume infected 

Bacterial Culture: Blood culture bottles 85% sensitivity 

  Routine cultures 50% sensitivity

Bacterial Peritonitis: Spontaneous versus secondary 

  Secondary: (1) polymicrobial; (2) total protein > 1.0 g/dL; (3) LDH > normal serum value; (4) glucose < 50 mg/dL

Food Fibers: Found in most cases of perforated viscus 

Cytology: Bizarre cells with large nuclei may represent reactive mesothelial cells and not malignancy. Malignant cells suggest a tumor. 

Source: Reprinted with permission. From: Haist SA, Robbins JB (eds.) Internal Medicine on Call, 4th ed. McGraw-Hill, 2005.

Pulmonary Artery Catheterization

(See Chapter 20)

Pulsus Paradoxus Measurement (Paradoxical Pulse)

(See also Chapter 20)

Indication

• Used in the evaluation of cardiac tamponade and other diseases (eg, severity of asthma)

Materials

• BP cuff and stethoscope

Background

Pulsus paradoxus is an exaggeration of the normal inspiratory drop in arterial pressure. Inspiration decreases intrathoracic pressure. The result is increased right atrial and right ventricular filling with an increase in right ventricular output. Because the pulmonary vascular bed also distends, these changes lead to a delay in left ventricular filling and subsequently decreased left ventricular output. This drop in systolic BP is usually < 10 mm Hg. In the case of cardiac compression (eg, acute asthma or pericardial tamponade), the right side of the heart fills more with inspiration and decreases the left ventricular volume to an even greater degree as a result of compression of the pericardial sac. This exaggerated decrease in left ventricular output decreases systolic pressure > 10 mm Hg. See Figure 20 1 for a graphic representation of a paradoxical pulse.

Procedure

1. For a simple, qualitative method palpate the radial pulse, which "disappears" on normal inspiration.

2. For a more precise quantitative method measure systolic BP at end-exhalation during tidal breathing.

a. Determine systolic BP at end-inspiration during tidal breathing.

b. The difference in systolic pressure between end-exhalation and end-inspiration should be < 10 mm Hg. If not, a so-called paradox exists.

3. Differential diagnosis includes pericardial effusion, cardiac tamponade, pericarditis, COPD, bronchial asthma, restrictive cardiomyopathy, hemorrhagic shock, massive PE, tricuspid stenosis, and mitral stenosis.

Skin Biopsy

Indications

• Any skin lesion or eruption for which the diagnosis is unclear
• Any refractory skin condition

Contraindications

• Any skin lesion suspected of being malignant (eg, melanoma) should be referred to a plastic surgeon or dermatologist for excisional biopsy rather than punch biopsy; full-thickness biopsy is critical for diagnosis and accurate staging.

Materials

• 2-, 3-, 4-, or 5-mm skin punch
• Minor procedure tray (see Table 13 1)
• Curved iris scissors and fine-toothed forceps (ordinary forceps may distort a small biopsy specimen and should not be used)
• Specimen bottle containing 10% formalin
• Suture material (3-0 or 4-0 nylon)

Procedure

1. If more than one lesion is present, choose one that is well developed and representative of the dermatosis. For patients with vesiculobullous disease, choose an early edematous lesion rather than a vesicle. Avoid lesions that are excoriated or infected.

2. Mark the biopsy area with a skin-marking pen. Inject lidocaine to form a skin wheal over the site of the biopsy.

3. After putting on sterile gloves and preparing a sterile field, obtain the punch biopsy specimen. Immobilize the skin with the fingers of one hand, applying pressure perpendicular to the skin wrinkle lines with the skin punch. Core out a cylinder of skin by twirling the punch between the fingers of the other hand. As the punch enters into the SQ fat, resistance lessens. At this point, remove the punch. The core of tissue usually pops up slightly and can be cut at the level of the SQ fat with a curved iris scissors without forceps. If a tissue core does not pop up, elevate it using a hypodermic needle or fine-toothed forceps. Be sure to include a portion of the SQ fat in the specimen.

4. Place the specimen in the specimen container.

5. Apply pressure with the gauze pad to achieve hemostasis.

6. Defects from 1.5- and 2-mm punches usually do not require suturing and heal with minimal scarring. Punch defects measuring 2 4 mm can generally be closed with a single suture.

7. Apply a dry dressing and remove it the following day.

8. Sutures can be removed as early as 3 d from the face and 7 10 d from other areas.

Complications

Infection (unusual); hemorrhage (usually controlled by simple application of pressure); keloid formation, especially in a patient with a history of keloid formation

Skin Testing

Indications

• Screening for current or past infection (eg, TB, coccidioidomycosis)
• Screening for immune competency (so-called anergy screen) in debilitated patients

Materials

• Appropriate antigen (usually 0.1 mL) (eg, 5 TU PPD)
• A small, short needle (25-, 26-, or 27-gauge)
• 1-mL syringe
• Alcohol swab

Procedure

1. Skin tests for delayed type hypersensitivity (type IV, tuberculin) are the most commonly administered and interpreted. Delayed hypersensitivity (so called because a lag time of 24 48 h is required for a reaction) is caused by the activation of sensitized lymphocytes after contact with an antigen (cell-mediated arm of the immune system). The inflammatory reaction results from direct cytotoxicity and the release of lymphokines. Allergy tests (immediate wheal and flare) are rarely performed by students or house officers.

2. The most commonly used site is the flexor surface of the forearm, approximately 4 in (10 cm) below the elbow crease.

3. Prep the area with alcohol. With the bevel of the 27-gauge needle up, introduce the needle into the upper layers of skin, but not into the subcutis. Inject 0.1 mL of antigen, such as PPD. The goal is to inject the antigen intradermally. If the injection has been done properly, a discrete white bleb approximately 10 mm in diameter (known as the Mantoux test) rises. The bleb should disappear soon, and no dressing is needed. If a bleb is not raised, move to another area and repeat the injection. Do not inject too superficially (in the epidermis); doing so causes epidermal dermal separation resulting in blister formation and an inaccurate test result.

4. Mark the test site with a pen; if multiple tests are being administered, identify each one. Document the site or sites in the patient's chart.

5. To interpret the skin test, examine the site 48 72 h after injection. If nonreactive, check again at 72 h. Measure the area of induration (the firm raised area), not the erythematous area. Use a ballpoint pen held at approximately a 30-degree angle and bring it lightly toward the raised area. Where the pen touches is the area of induration. Measure two diameters and take the average.

6. It is important to check the PPD and other tests at intervals. If the patient develops a severe reaction to the skin test, apply hydrocortisone cream to prevent skin sloughing.

Specific Skin Tests

TST (Tuberculin Skin Testing):

Routine TST on persons at low risk is not recommended. Persons at high risk should undergo periodic TST: those with CXR findings suspicious for TB or recent contact with known or suspected TB cases (includes health care workers); immigrants from high-risk areas (Asia, Africa, Middle East, Latin America), the medically underserved (IV drug abusers, persons with alcoholism, homeless persons); persons undergoing long-term institutionalization; and persons with HIV infection and others who are immunosuppressed.

The Mantoux test is the standard technique for TST and relies on the intradermal injection of PPD. The tine test for TB is no longer recommended by the CDC. The PPD comes in three tuberculin unit strengths: 1 TU (first), 5 TU (intermediate), and 250 TU (second). One TU is used if the patient is expected to be hypersensitive (history of a positive skin test); 5 TU is the standard initial screening test. A patient who has a negative response to a 5-TU test dose may react to the 250-TU solution. A patient who does not respond to 250-TU is considered nonreactive to PPD. A patient may not react if he or she has not been exposed to the antigen or is anergic and unable to respond to any antigen challenge. A positive TST indicates the presence of Mycobacterium tuberculosis infection, either active or past (dormant), and intact cell-mediated immunity.

Interpretation of a positive PPD test is based on the clinical scenario. Patients who have been previously immunized with percutaneous BCG may give a false-positive PPD, usually 10 mm or less.

• 0 5 mm induration: Negative response
• 5 mm: Considered positive in contacts of known TB cases, CXR findings consistent with TB infection or HIV infection or in patients who are immunosuppressed, occasionally in non-TB mycobacterial infection due to cross reactivity
• 10 mm induration: Considered positive in patients with chronic disease (diabetes, alcoholism, IV drug abuse, other chronic diseases), homeless persons, immigrants from known TB regions, and children < 4 y
• > 15 mm induration: Positive in persons who are healthy and otherwise do not meet the preceding risk categories

Anergy Screen (Anergy Battery):

An anergy screen is based on the assumption that a patient has been exposed in the past to certain common antigens and that a healthy person is able to mount a reaction to them. In the screen, an antigen such as mumps or Candida is applied, and the results are read as in a PPD test (a reaction of > 5 mm induration is considered a positive test and indicates intact cellular immunity). Anergy screens are sometimes used to evaluate a patient's immunologic status. Test is not commonly used today.

Thoracentesis

Indications

• Determining the cause of a pleural effusion
• Therapeutic removal of pleural fluid in the event of respiratory distress
• Aspirating small pneumothoraces when the risk of recurrence is small (eg, postoperative without lung injury)
• Instilling sclerosing compounds (eg, tetracycline) to obliterate the pleural space

Contraindications

• No absolute contraindications. Relative: pneumothorax, hemothorax, any major respiratory impairment on the contralateral side; coagulopathy

Materials

• Prepackaged thoracentesis kit with either needle or catheter (preferred)

  or

• Minor procedure tray (Table 13 1)
• 20- to 60-mL syringe, 20- or 22-gauge needle 11/2-in (4 cm) needle, three-way stopcock
• Specimen containers

Background

Thoracentesis is a surgical puncture on the chest wall for aspiration of fluid or air from the pleural cavity. The area of pleural effusion is dull to percussion with decreased breath sounds. Pleural fluid causes blunting of the costophrenic angles on CXR. Blunting usually indicates that at least 300 mL of fluid is present. If you suspect that less than 300 mL of fluid is present or that the fluid is loculated (trapped and not free-flowing), obtain a lateral decubitus film. Loculated effusions do not layer out. Thoracentesis can be done safely on fluid visualized on a lateral decubitus film if at least 10 mm of fluid is measurable on the decubitus x-ray. Ultrasonography may also be used to localize a small or loculated effusion.

Procedure

1. Explain the procedure, and have the patient sign an informed consent form. Have the patient sit up comfortably, preferably leaning forward slightly on a bedside tray table. Ask the patient to practice increasing intrathoracic pressure using the Valsalva maneuver or by humming.

2. The usual site for thoracentesis is the posterior lateral aspect of the back superior to the diaphragm but inferior to the top of the fluid level. Confirm the site by counting the ribs on the basis of the CXR and percussing out the fluid level. Avoid going below the 8th ICS because of the risk of peritoneal perforation. A good frame of reference is the inferior angle of the scapula, which is located horizontally at the 7th rib or 7th intercostal space.

3. Use sterile technique, including gloves, chlorhexidine, and drapes. Thoracentesis kits come with an adherent drape with a hole in it.

4. Make a skin wheal over the proposed site with a 25-gauge needle and lidocaine. Change to a 22-gauge, 1 -in (4 cm) needle and infiltrate up and over the rib (Figure 13 19); try to anesthetize the deeper structures and the pleura. During this time, aspirate back for pleural fluid. Once fluid returns, note the depth of the needle and mark it with a hemostat. This maneuver gives you an approximate depth. Remove the needle.

5. Use a hemostat to measure the 14- to 18-gauge thoracentesis needle to the same depth as the first needle. Penetrate through the anesthetized area with the thoracentesis needle. Make sure that you "march" over the top of the rib to avoid the neurovascular bundle that runs below the rib (see Figure 13 19). With the three-way stopcock attached, advance the thoracentesis catheter through the needle, withdraw the needle from the chest, and place the protective needle cover over the end of the needle to prevent injury to the catheter. Next, aspirate the amount of pleural fluid needed. Turn the stopcock, and evacuate the fluid through the tubing. Never remove more than 1000 1500 mL per tap in patients with chronic effusions (eg, malignant effusions). Doing so can cause hypotension or development of pulmonary edema due to reexpansion of compressed alveoli. In acute effusions (eg, traumatic hemothorax or postoperative pleural effusions after cardiac surgery) > 1000 mL can be removed at one time without major side effects. In the event of reexpansion pulmonary edema, treat the patient with aggressive diuresis, supplemental oxygenation, potential endotracheal intubation, and continuous hemodynamic and saturation monitoring.

6. Have the patient hum or do the Valsalva maneuver as you withdraw the catheter. This maneuver increases intrathoracic pressure and decreases the risk of pneumothorax. Place a sterile dressing over the site.

7. Obtain a CXR to evaluate the fluid level and to rule out pneumothorax. An expiratory film is preferred because it is superior in identification of a small pneumothorax.

8. Distribute specimens in containers, label slips, and send them to the lab. Always order pH (collect in an ABG syringe), specific gravity, protein, LDH, cell count and differential, glucose, Gram stain and cultures, acid-fast cultures and smears, and fungal cultures and smears. Optional lab studies are cytology if malignancy is suspected, amylase if effusion secondary to pancreatitis (usually on the left) or esophageal perforation is suspected, and Sudan stain and triglycerides (> 110 mg/dL) if chylothorax is suspected.

Figure 13 19.

In thoracentesis, the needle is passed over the top of the rib to avoid the neurovascular bundle.

Complications

Pneumothorax, hemothorax, infection, pulmonary laceration, hypotension, hypoxia due to / mismatch in the newly aerated lung segment

Differential Diagnosis of Pleural Fluid

(See Chapter 3) Transudate suggests nephrosis, CHF, cirrhosis; exudate, infection (pneumonia, TB), malignancy, empyema, peritoneal dialysis, pancreatitis, or chylothorax. Table 13 7 shows the differential diagnosis.

Table 13 7 Differential Diagnosis of Pleural Fluid

Lab Value	Transudate	Exudate
Appearance	Clear yellow	Clear or turbid
Specific gravity	<1.016	>1.016
Absolute protein	<3 g/100 mL	>3 g/100 mL
Protein (pleural to serum ratio)	<0.5	>0.5
LDH (pleural to serum ratio)	<0.6	>0.6
Absolute LDH	<200 IU	>200 IU
Glucose (serum to pleural ratio)	<1	>1
Fibrinogen (clot)	No	Yes
WBC (pleural)	Very low	>2500/mm3
Differential (pleural)		PMN early, monocytes later
Other Selected Tests
Cytology: Bizarre cells with large nuclei may represent reactive mesothelial cells and not malignancy. Malignant cells suggest a tumor.
pH: Generally > 7.3. If between 7.2 and 7.3, suspect TB or malignancy or both. If < 7.2, suspect empyema.
Glucose: Normal pleural fluid glucose is 2/3 serum glucose. Pleural fluid glucose is much lower than serum glucose in effusions due to rheumatoid arthritis (0 16 mg/100 mL); low ,< 40 mg/100 mL in empyema.
Triglycerides and positive Sudan stain: Chylothorax

LDH = lactate dehydrogenase; WBC = white blood cells; RBC = red blood cells; PMN = polymorphonuclear neutrophils; TB = tuberculosis.

Urinary Tract Procedures

Bladder Catheterization

Indications

• Relief of urinary retention
• Collection of an uncontaminated urine specimen for diagnostic purposes
• Monitoring of urinary output in critically ill patients
• Bladder tests (cystogram, cystometrogram)

Contraindications

• Urethral disruption, often associated with pelvic fracture
• Acute prostatitis (relative contraindication)

Materials

• Prepackaged bladder catheter tray (may or may not include a Foley catheter)
• Catheter (Figure 13 20):

Foley: Balloon at the tip to keep it in the bladder. Use a 16- to 18 Fr for adults (the higher the number, the larger the diameter). Irrigation catheters (three-way Foley) should be larger (20 22 Fr).

Coud (pronounced "coo-DAY"): An elbow-tipped catheter useful in men with prostatic hypertrophy (the catheter is passed with the tip pointing to the 12 o'clock position).

Red rubber catheter (Robinson): Plain rubber or latex catheter without a balloon, usually used for in-and-out catheterization, in which urine is removed but the catheter is not left indwelling.

Figure 13 20.

Bladder catheters, top to bottom: straight Robinson or red rubber catheter, Foley catheter with standard 5-mL balloon, Coud catheter, and three-way irrigating catheter with 30-mL balloon. Catheters have been shortened for illustrative purposes.

Procedure

1. Use strict aseptic technique.

2. Have the patient lie supine in a well-lighted area; female patients with knees flexed wide and heels together to get adequate exposure of the meatus.

3. Get all the materials ready before attempting to insert the catheter. Open the kit, and put on the gloves. Open the prep solution, and soak the cotton balls. Apply the sterile drapes.

4. Inflate and deflate the balloon of the Foley catheter to ensure its proper function. Coat the end of the catheter with lubricant jelly.

5. In female patients, use one gloved hand to prep the urethral meatus in a pubis-toward-anus direction; hold the labia apart with the other gloved hand. For uncircumcised male patients, retract the foreskin to prep the glans; use a gloved hand to hold the penis still.

6. Do not let the hand used to hold the penis or labia touch the catheter to insert it; use the disposable forceps in the kit insert the catheter. Or, use the forceps to prep, and then use the gloved hand to insert the catheter.

7. For male patients, stretch the penis upward perpendicular to the body to eliminate any internal folds in the urethra that might lead to a false passage. Use steady, gentle pressure to advance the catheter. The bulbous urethra is the most likely part to tear. Any significant resistance encountered may represent a stricture and requires urologic consultation. In men with BPH, a Coud tip catheter may facilitate passage. Tricks used to get a catheter to pass in a male patient are to make sure that the penis is well stretched and to instill 3050 mL of sterile water-based surgical lubricant (K-Y jelly) into the urethra with a catheter-tipped syringe before passing the catheter. Viscous lidocaine jelly for urologic use can help lubricate and relieve the discomfort of difficult catheter placement. Allow at least 5 min after instillation of the lidocaine jelly for the anesthetic effect to take place.

8. For both male and female patients, insert the catheter to the hilt of the drainage end. In male patients, compress the penis toward the pubis. These maneuvers ensure that the balloon inflates in the bladder and not in the urethra. Inflate the balloon with 5 10 mL of sterile water or, occasionally, air. After inflation, pull the catheter back so that the balloon comes to rest on the bladder neck. There should be good urine return when the catheter is in place. If a large amount of lubricant jelly was placed into the urethra, you may have to flush the catheter with sterile saline to clear the excess lubricant. A catheter that will not irrigate is probably in the urethra, not the bladder.

9. In uncircumcised male patients, reposition the foreskin to prevent massive edema of the glans after the catheter is inserted.

10. Catheters in female patients can be taped to the leg. In male patients, the catheter should be taped to the abdominal wall to decrease stress on the posterior urethra and help prevent stricture formation. The catheter is usually attached to a gravity drainage bag or a device for measuring the amount of urine. Many new kits come with the catheter already secured to the drainage bag. These systems are considered closed; do not open them if at all possible.

"In-and-Out" Catheterized Urine

1. If urine is needed for analysis or for C&S, especially for a female patient, a so-called in-and-out catheterization can be done. This procedure is also useful for measuring residual urine in male or female patients. The incidence of inducing infection with this procedure is about 3%.

2. The procedure is identical to that described for bladder catheterization. The main difference is that a red rubber catheter (no balloon) is often used and is removed immediately after the specimen is collected.

Clean-Catch Urine Specimen

1. A clean-catch urine is useful for routine urinalysis, is usually good for culturing urine from male patients, but is only fair for culturing urine from female patients because of the potential for contamination.

1. For male patients:

a. Expose the glans, clean with a povidone iodine solution and dry the area with a sterile pad.

b. Collect midstream urine in a sterile container after the initial flow has escaped.

3. For female patients:

a. Separate the labia widely to expose the urethral meatus; keep the labia spread throughout the procedure.

b. Cleanse the urethral meatus with povidone iodine solution from front to back, and rinse with sterile water.

c. Catch the midstream portion of the urine in a sterile container.

Percutaneous Suprapubic Bladder Aspiration

Indications

Used most frequently in young children.

• Inability to obtain urine with a less invasive method
• Urethral abnormalities
• Refractory UTI

Contraindications

• Voiding within the last hour (children)
• Inability to percuss the bladder

Procedure

1. This procedure is almost exclusively limited to infants younger than 6 mo.

2. Immobilize the child. Do not attempt this procedure if the child has voided within the last hour.

3. Palpate the bladder above the pubic symphysis (the bladder sticks out high above the pubis in a young child when it is full). Some clinicians suggest occluding the urethra in boys by holding the penis and in girls by inserting a finger in the rectum to exert pressure. Percuss out the limits of the bladder.

4. Obtain a 20-mL syringe with a 23- or 25-gauge, 1 -in (4 cm) needle. Prep with povidone iodine and alcohol 1 in (1.5 4 cm) above the pubis. Anesthesia is not routinely used.

5. Insert the needle perpendicular to the skin in the midline; maintain negative pressure on the downstroke and on withdrawal until urine is obtained (Figure 13 21).

6. If no urine is obtained, wait at least 1 h before reattempting the procedure.

Figure 13 21.

Technique and anatomic structures in suprapubic bladder aspiration. (Reprinted, with permission, from: Gomella TL [ed] Neonatology: Basic Management, On-Call Problems, Diseases, Drugs, 5th ed. McGraw-Hill, 2004.)

Venipuncture

Indications

• Venipuncture (phlebotomy) is the puncture of a vein to obtain a sample of venous blood for analysis.

Materials

• Tourniquet (1 -in [4 cm] Penrose drain or BP cuff is acceptable replacement)
• Alcohol prep pad, gauze pad, and adhesive bandage
• Proper specimen tubes for desired studies (red top, purple top, etc) (Table 13 8)
• Appropriate-sized syringe for volume of blood needed (5 mL, 10 mL, etc), or Vacutainer tube and appropriate needle and Vacutainer holder. The BD Eclipse blood collection system includes a manually activated needle shield.
• A 20- to 22-gauge needle (Larger needles are uncomfortable, and smaller ones can cause hemolysis or clotting; the higher the gauge number, the smaller the needle, see Figure 13 1A.)

Table 13 8 Tube Guide for Venipuncture Using the Vacutainer System (from BD Biosciences)

Vacutainer Tube	Vacutainer Hemogard Closure	Additive	Number or Inversions at Blood Collection (Invert gently, do not shake)	Laboratory Use
Black/red marbled ("tiger top")	Gold	Clot activator and gel for serum separation	5	SST brand tube for serum demonstrations in chemistry. Tube inversions ensure mixing of clot activator with blood and clotting within 30 min
Green/red marbled	Light green	Lithium heparin and gel for plasma separation	8	PST brand tube for plasma determinations in chemistry. Tube inversions prevent clotting
Red	Red	None	0	For serum determinations in chemistry, serology, and blood banking
Yellow/black marbled	Orange	Thrombin	8	For stat serum determinations in chemistry. Tube inversions prevent clotting, usually in less than 5 min
Royal blue	Royal blue	Sodium heparin	8	For trace element, toxicology, and nutrient determinations. Special stopper formulation offers the lowest verified levels of trace elements available (see package insert)
		Na EDTA	8
		None	0
Green	Green	Sodium heparin	8	For plasma determinations in chemistry. Tube inversions prevent clotting
		Lithium heparin	8
		Ammonium heparin	8
Gray	Gray	Potassium oxalate/Sodium fluoride	8	For glucose determinations. Tube inversions ensure proper mixing of additive and blood. Oxalate and heparin, anticoagulants, will give samples that are serum
		Sodium fluoride	8
		Lithium iodoacetate	8
Brown	Brown	Sodium heparin	8	For lead determinations. This tube is certified to contain less than .01 mcg/mL (ppm) lead. Tube inversions prevent clotting
Yellow	Yellow	Sodium polyanetholesulfonate (SPS)	8	For blood culture specimen collections in microbiology. Tube inversions prevent clotting
Lavender	Lavender	Liquid EDTA	8	For whole blood hematology determinations. Tube inversions prevent clotting
		Freeze-dried Na EDTA	8
Light blue	Light blue	0.105 M sodium citrate (3.2%)	8	For coagulation determinations on plasma specimens. Tube inversions prevent clotting. Note: Certain tests require chilled specimens. Follow recommended procedures for collection and transport of specimen
		0.129 M sodium citrate (3.8%)	8

Procedure

Blood cultures, IV techniques, and arterial punctures are discussed in other sections of the chapter.

1. Collect the necessary materials before you begin, including extras in case there is a problem.

2. The common sites for routine venipuncture are the veins of the antecubital fossa (see Figure 13 12). Alternative sites include the dorsum of the hand, the forearm, the saphenous vein near the medial malleolus, and the external jugular vein. If peripheral sites are unacceptable, use the femoral vein. Never draw a blood sample proximal to an IV site because of the high concentration of IV fluid in the veins.

3. Apply the tourniquet at least 2 3 in (5 8 cm) above the venipuncture site. Have the patient make a fist to help engorge the vein. If veins are difficult to locate, try gently slapping or flicking the vein to cause reflex dilation, hanging the extremity in a dependent position, wrapping the extremity in a warm wet towel, substituting a BP cuff for the standard tourniquet, or applying nitroglycerin paste below and over the area to help dilate the veins.

4. Swab the site with the alcohol prep pad, and allow the alcohol to evaporate.

5. The Vacutainer system has become the standard means of collecting blood for analysis. Screw a 20- to 22-gauge Vacutainer needle on the Vacutainer cup, and rotate the safety shield back. In the Eclipse needle system (BD Biosciences) a shield covering the end of the needle is manually activated after the sample is collected. Remove the protective needle cap.

6. Keep the needle bevel up, and puncture the skin alongside the vein. After the needle is through the skin, use the thumb of your free hand to stabilize the vein and prevent it from rolling. Enter the vein on the side at about a 30-degree angle. An alternative technique is to enter both the skin and vein in one stick. This maneuver requires practice because the vein is often punctured through and through.

7. Advance the appropriate collection tube (see Table 13 8) onto the needle inside the Vacutainer cup. The vacuum inside the tube automatically collects the sample. If you hold the Vacutainer steady, several tubes can be collected in this manner.

8. After the blood is collected, remove the tourniquet, withdraw the needle, and apply firm pressure with the alcohol swab or sterile gauze for 2 3 min. The BD Eclipse needle allows rapid one-handed reshielding of the needle tip. Elevation of the extremity is helpful for limiting hematoma. Bending the arm actually increases the size of the venipuncture site and should be discouraged.

9. If no peripheral veins can be located, attempt to puncture the femoral vein. Locate the femoral artery using the NAVEL system. The femoral vein should be just medial to the femoral artery. After prepping the skin, insert the needle perpendicular to the skin, and gently aspirate. The vein should be about 1 1 in (2.5 4 cm) below the skin. Apply firm pressure after collecting the sample; hematomas are frequent complications of femoral venipuncture. If the the femoral artery is accidentally entered, it is acceptable to collect the sample. Apply pressure for a longer period (5 min) if the artery is entered.

10. In children and elderly persons with fragile veins, a butterfly (21 25 gauge) can be used to obtain a sample (see Figure 13 14). Attach a syringe, or use a needleless Vacutainer system.

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