CLINICIAN’S POCKET REFERENCE - PART 5 pptx

Technique 1. Examine the fundus for evidence of papilledema, and review the CT or MRF of the head if available. Discuss the relative safety and lack of discomfort to the patient to dis- pel any myths. Some clinicians prefer to call the procedure a “subarachnoid analysis” rather than a spinal tap. As long as the procedure and the risks are outlined, most pa- tients will 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 (Fig. 13–16). This position enhances flex- ion 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. In an obese patient or a patient with arthritis or scoliosis, the sitting po- sition, leaning forward, may be preferred. 3. Palpate the supracristal plane (see under Background) and carefully determine the loca- tion of the L4–L5 interspace. 4. Open the kit, put on sterile gloves, and prep the area with povidone–iodine solution in a circular fashion and covering several interspaces. Next, drape the patient. 5. With a 25-gauge needle and 1idocaine, raise a skin wheal over the L4–L5 interspace. Anesthetize the deeper structures with a 22-gauge needle. 6. Examine the spinal needle with a 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 30–45-de- gree angle, in the midline and parallel to the bed (see Fig. 13–16). 7. Advance 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 re- place the stylet prior to 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 The needle may be withdrawn, however, with the stylet removed.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 think that you are within the subarachnoid space, inject 1 mL of air because it is not uncommon for a piece of tissue to clog the needle. Never inject saline or distilled water. If no air returns and if spinal fluid cannot be aspirated, the bevel of the needle probably lies in the epidural space; advance it with the stylet in place. 9. When fluid returns, attach a manometer and stopcock and measure the pressure. Nor- mal 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 needle position or ob- structed 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 0.5–2.0-mL samples in serial, labeled containers. Send them to the lab in this order: • First tube for bacteriology: Gram’s stain, routine C&S, AFB, and fungal cultures and stains • Second tube for glucose and protein: If a work-up for MS, order electrophoresis to detect oligoclonal banding and assay for myelin basic protein characteristic of MS • Third tube for cell count: CBC with differential 284 Clinician’s Pocket Reference, 9th Edition 13 13 Bedside Procedures 285 13 Subarachnoid space Cauda equina L4 L5 S1 L5L4 L4 FIGURE 13–16 When performing a lumbar puncture, place the patient in the lat- eral decubitus position, and locate the L4–L5 interspace. Control the spinal needle with two hands, and enter the subarachnoid space. • Fourth tube for special studies as clinically indicated: VDRL neurosyphilis CIEP (counterimmunoelectrophoresis) for bacterial antigens such as H. influenzae, S. Pneu- moniae, N. meningitidis) PCR assay for tuberculous meningitis or herpes simplex encephalitis (allows rapid diagno- sis) If Cryptococcus neoformans is suspected (most common cause of meningitis in AIDS pa- tients) 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 permits a better differentiation between a 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 a 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 recumbent for 6–12 h, and encourage an increased fluid intake to help prevent “spinal headaches.” 13. Interpret the results based on Table 13–4. Complications • Spinal headache: The most common complication (about 20%), this appears within the first 24 h after the puncture. It goes away when the patient is lying down and is aggravated when the patient sits up. It is usually characterized by a severe throbbing pain in the occipital region and can last a week. It is thought to be caused by in- tracranial traction caused by the acute volume depletion of CSF and by persistent leakage from the puncture site. To help prevent spinal headaches, keep the patient re- cumbent for 6–12 h, encourage the intake of fluids, use the smallest needle possible, and keep the bevel of the needle parallel to the long axis of the body to help prevent a persistent CSF 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 pains in the legs), stop the procedure. • Herniation of either the cerebellum or the medulla: Occurs rarely, during or after a spinal tap, usually in a patient with increased intracranial pressure. This complica- tion can often be reversed medically if it is recognized early. • Meningitis. • Bleeding in the subarachnoid/subdural space can occur with resulting paralysis es- pecially if the patient is receiving anticoagulants or has severe liver disease with a coagulopathy. ORTHOSTATIC BLOOD PRESSURE MEASUREMENT Indication • Assessment of volume depletion Materials • Blood pressure cuff and stethoscope 286 Clinician’s Pocket Reference, 9th Edition 13 13 TABLE 13–4 Differential Diagnosis of Cerebrospinal Fluid Opening Protein Glucose Pressure (mg/ (mg/ Cells Condition Color (mm H 2 O) 100 mL) 100 mL) (#/mm 3 ) 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 Clear or Normal or Normal or Nor mal 10–500 (“aseptic meningitis”) opalescent slightly slightly lymphocytes increased increased PMNs Bacterial Opalescent Increased 50–10,000 Increased, 25–10,000 infection yellow, may usually Ͻ20 PMNs clot Granulomatous Clear or Often Increased, Decreased, 10–500 infection opalescent increased but usually usually lymphocytes (TB, fungal) Ͻ500 Ͻ20–40 NEUROLOGIC Guillain–Barré Clear or Normal Markedly Normal Normal or Syndrome Cloudy increased increased lymphocytes (continued ) 287 13 TABLE 13–4 (Continued) Opening Protein Glucose Pressure (mg/100 (mg/100 Cells Condition Color (mm H 2 O) mL) mL) (#/mm 3 ) Multiple sclerosis Clear Normal Normal or Normal 0–20 lymphocytes increased Pseudotumor cerebri Clear Increased Normal Normal Normal MISCELLANEOUS Neoplasm Clear or Increased Normal or Nor mal or Normal or xanthochromic increased decreased increased lymphocytes Traumatic tap Bloody, no Normal Normal SI increased RBC = peripheral xanthochromia blood; Less RBC in tube 4 than in tube 1 Subarachnoid Bloody or Usually Increased Normal WBC/RBC hemorrhage xanthochromic increased ratio same after 2–8 h as blood Abbreviations: WBC = white blood cell; RBC = red blood cell; PMNs = polymorphonuclear neutrophils. 288 Procedure 1. Changes in blood pressure 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 demon- stration 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. Then 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, determine the BP and pulse again. 5. A drop in systolic BP greater than 10 mm Hg or an increase in pulse rate greater than 20 (16 if elderly) suggests volume depletion. A change in heart rate is more sensitive and occurs with a lesser degree of volume depletion. Other causes include peripheral vascular disease, surgical sympathectomy, diabetes, and medications (prazosin, hy- dralazine, or reserpine). PELVIC EXAMINATION Indications • Part of a complete physical examination in the female • Used to assist in the diagnosis of diseases and conditions of the female genital tract Materials • Gloves • Vaginal speculum and lubricant • Slides, fixative (Pap aerosol spray, etc), cotton swabs, endocervical brush and cervi- cal spatula prepared for a Pap smear • Materials for other diagnostic tests: Culture media to test for gonorrhea, Chlamy- dia, herpes; sterile cotton swabs, plain glass slides, KOH, and normal saline solu- tions, as needed Procedure 1. The pelvic exam should be carried out in a comfortable fashion for both the patient and physician. A female assistant must be present for the procedure. The patient should be draped appropriately with her feet placed in the stirrups on the examining table. Pre- pare a low stool, a good light source, and all needed supplies before the exam begins. In unusual situations examinations are conducted on a stretcher or bed; raise the pa- tients buttocks on one or two pillows to elevate the perineum off the mattress. 2. Inform the patient of each move in advance. Glove hands before proceeding. 3. General inspection: a. Observe the skin of the perineum for swelling, ulcers, condylomata (venereal warts), or 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, neo- plasm, and abscess of Bartholin’s gland at the 4 or 8 o’clock positions. d. Inspect the vaginal orifice for discharge, or protrusion of the walls (cystocele, rec- tocele, urethral prolapse). e. Note the condition of the hymen. 13 Bedside Procedures 289 13 4. Speculum examination: a. Use a speculum moistened with warm water not with lubricant (lubricant will in- terfere with Pap tests and slide studies). Check the temperature on the patient’s leg to see if the speculum is comfortable. b. Because the anterior wall of the vagina is close to the urethra and bladder, do not exert pressure in this area. Pressure should be placed 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, discharge. e. Inspect the vagina for secretions and obtain specimens for a Pap smear, other smear, or culture (see tests for vaginal infections and Pap smear in item 7). f. Inspect the vaginal wall; rotate the speculum as you draw it out to see the entire canal. 5. Bimanual examination: a. For this part, stand up. It is best to use whichever hand is comfortable to do the in- ternal vaginal exam. Remove the glove from the hand that will examine the ab- domen. b. Place lubricant on the first and second gloved fingers, and then, keeping pressure on the posterior fornix, introduce them into the vagina. c. Palpate the tissue at 5 and 7 o’clock between the first and second fingers and the thumb to rule out any abnormality of Bartholin’s gland. Likewise, palpate the ure- thra and paraurethral (Skene’s) gland. 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, or cystocele. e. Palpate the cervix. Note the size, shape, consistency, and motility, and test for ten- derness (the so-called chandelier sign or marked cervical tenderness, which is positive in PID). f. With your fingers in the vagina posterior to the cervix and your hand on the ab- domen 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 any masses, consistency, and motility. Unless the fallopian tubes are diseased, they usually are not palpable. 6. Rectovaginal examination: a. Insert your index finger into the vagina, and place the well-lubricated middle fin- ger in the rectum. b. Palpate the posterior surface of the uterus and the broad ligament for nodularity, tenderness, or other masses. Examine the uterosacral and rectovaginal septum. Nodularity here 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 the early detection of cervical intraepithelial neoplasia and carcinoma. Endometrial carcinoma is occasionally identified on routine Pap smears. It is recommended that low-risk patients have routine Pap smears done every 2–3 y, but only after three annual Pap smears are negative. High-risk patients such as those exposed to in utero DES, patients with HPV infections, history of cervical dysplasia or cervical intraep- 290 Clinician’s Pocket Reference, 9th Edition 13 ithelial neoplasia, more than two sexual partners in the patient’s lifetime, and intercourse prior to age 20 should obtain an annual Pap smear. a. With the 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 commercially available spray fixative. The slide must be fixed within 10 s or a drying artifact may occur. b. Next, obtain a specimen from the endocervical canal using a cotton swab or com- mercial available endocervical brush and prepare the slide as described in part a. c. Using a wooden spatula, an additional specimen should be obtained from the pos- terior/lateral vaginal pool of fluid and smeared on a slide. d. Complete the appropriate lab slips. Forewarn the patient that she may experience some spotty vaginal bleeding following the Pap smear. 8. Tests for cervical/vaginal infections: a. GC culture: Use a sterile cotton swab to obtain a specimen from the endocervical canal and plate it out on Thayer–Martin medium. b. Vaginal saline (wet) prep: Helpful in the diagnosis of Trichomonas vaginalis or Gardnerella vaginalis. A thin, foamy, white, pruritic discharge is associated with a Trichomonas infection. Mix a drop of discharge with a drop of NS on a glass slide and cover the drop with a coverslip. It is important to observe the slide while it is still warm to see the flagellated, motile trichomonads. If a patient has a thin, watery, gray, malodorous discharge, an infection with Gardnerella vaginalis may be present. Bacterial vaginosis is most often caused by G. vaginalis and can be di- agnosed by the presence of “clue cells,” which represent polymorphonuclear white cells dotted with the G. vaginalis bacteria, a vaginal pH of > 4.5 and a fishy amine odor with addition of KOH to the secretions. Alternatively, these can be seen by using a hanging drop of saline and a concave slide. Lactobacillus is normally the predominant bacteria in the vagina in the absence of specific infection and the nor- mal pH is usually < 4.5. c. Potassium hydroxide prep: If a thick, white, curdy discharge is present, the pa- tient may have a Candida albicans (monilial) yeast infection. Prepare a slide with one drop of discharge and one drop of aqueous 10% KOH solution. The KOH dis- solves the epithelial cells and debris and facilitates viewing of the hyphae and mycelia of the fungus that causes the infection. d. Gram’s stain: Material can easily be stained in the usual fashion (Chapter 7, page 122). Gram-negative intracellular diplococci (so-called GNIDs) are pathogno- monic of Neisseria gonorrhoeae. The most commonly found bacteria in Gram’s 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 demonstrate herpes inclusion bodies. A herpes culture may be done by taking a viral culture swab of the suspicious lesion or of the endocervix. f. Chlamydia cultures: Special swabs can be obtained from the microbiology lab for Chlamydia cultures. PERICARDIOCENTESIS Indications • Emergency treatment of cardiac tamponade • Diagnose the cause of pericardial effusion 13 Bedside Procedures 291 13 Contraindications • Minimal pericardial effusion (< 200 mL) • After CABG due to risk of injury to grafts • Uncorrected coagulopathy Materials • Electrocardiogram machine • Prepackaged pericardiocentesis kit or Procedure and instrument tray (page 240) with pericardiocentesis needle or 16–18-gauge needle 10 cm long Background Cardiac tamponade results in decreased cardiac output, increased right atrial filling pres- sures, and a pronounced pulsus paradoxus. Procedure 1. If time permits, use sterile prep and draping with gown, mask, and gloves. 2. Draining the pericardium can be approached either through the left para xiphoid or the left parasternal fourth intercostal space. The para xiphoid is safer, more commonly used, and described here (Fig. 13–17). 3. Anesthetize the insertion site with lidocaine. Connect the needle with an alligator clip to lead V on the ECG machine. Attach the limb leads, and monitor the machine. 4. Insert the pericardiocentesis needle just to the left of the xiphoid 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 the ventricular wall is felt, withdraw the needle slightly. Additionally, if the needle contacts the myocardium, pronounced ST segment elevation will be noted on the ECG. 6. If performed for cardiac tamponade, removal of as little as 50 mL of fluid dramatically improves blood pressure and decreases right atrial pressure. 7. Blood from a bloody pericardial effusion is usually defibrinated and will not clot, whereas blood from the ventricle will clot. 8. Send fluid for hematocrit, cell count, or cytology if indicated. Serous fluid is consistent with CHF, bacterial infection, TB, hypoalbuminemia, or viral pericarditis. Bloody fluid (HCT >10%) may result from trauma; be iatrogenic; or due to MI, uremia, coagulopa- thy, or malignancy (lymphoma, leukemia, breast, lung most common) 9. If continuous drainage is necessary, use a guidewire to place a 16-gauge intravenous catheter. Complications Arrhythmia, ventricular puncture, lung injury PERIPHERALLY INSERTED CENTRAL CATHETER (PICC LINE) Indications • Home infusion of hypertonic or irrigating solutions and drugs • Long-term infusion of medications (antibiotics, chemotherapeutics) • TPN • Repetitive venous blood sampling 292 Clinician’s Pocket Reference, 9th Edition 13 Contraindications • Infection over placement site • Failure 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) • Tourniquet, sterile gloves, mask, sterile gown, heparin flush, 10-mL syringes 13 Bedside Procedures 293 13 7 Parasternal approach Paraxyphoid approach To ECG, V lead To ECG, V lead 1 2 3 4 5 6 FIGURE 13–17 Techniques for pericardiocentesis. The paraxiphoid approach is the most popular. (Reprinted, with permission, from: Stillman RM [ed]: Surgery, Diag- nosis, and Therapy, Appleton & Lange, Norwalk CT, 1989.) [...]... “strengths”: 1 TU (“first”), 5 TU (“intermediate”), and 250 TU (“second”) 1 TU is used if the patient is expected to be hypersensitive (history of a positive 13 304 Clinician’s Pocket Reference, 9th Edition 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 the 250 -TU is considered... dermatologist for excisional biopsy rather than a punch biopsy Materials • 2-, 3-, 4-, or 5- mm skin punch • Minor procedure tray (page 240) • 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 • Suturing materials ( 3-0 or 4-0 nylon) Procedure 13 1 If more than one lesion is present, choose one... site with a 2 5- gauge needle and 1idocaine Change to a 22-gauge, 1¹ ₂-in needle and infiltrate up and over the rib (Fig 13–20); try 13 Pleura Lung tissue 1 Local anesthetic 2 Rib Effusion Neurovascular bundle (nerve, artery, vein) FIGURE 13–20 When performing a thoracentesis, the needle is passed over the top of the rib to avoid the neurovascular bundle 306 5 6 7 8 Clinician’s Pocket Reference, 9th... catheter], Foley catheter with standard 5- mL balloon, the Coudé catheter, and “three-way” irrigating catheter with 30-mL balloon Catheters have been shortened for illustrative purposes 308 13 Clinician’s Pocket Reference, 9th Edition 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 females, use one gloved hand to... male and by inserting a finger in the rectum to exert pressure in the female Percuss out the limits of the bladder 4 Obtain a 20-mL syringe with a 2 3- or 2 5- gauge, 1¹ ₂-in needle Prep with povidone–iodine and alcohol 0 .5 1 .5 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... WBC/mL (if obtained >3 h after the injury) ≥1 75 units amylase/dL Bacteria on Gram’s stain Bile (by inspection or chemical determination of bilirubin content) Food particles (microscopic analysis of strained or spun specimen) Pink fluid on free aspiration 50 ,000–100,000 RBC/mL in blunt trauma 100 50 0 WBC/mL 75 1 75 units amylase/dL Clear aspirate ≤ 100 WBC/mL ≤ 75 units amylase/dL Source: Reprinted, with... Indications • Screening for current or past infectious agent (TB, coccidioidomycosis, etc) • 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 (2 5- , 2 6-, or 27-gauge) 1-mL syringe Alcohol swab Procedure 1 Skin tests for delayed type hypersensitivity (type IV, tuberculin) are the most commonly... syringe, 2 0- or 22-gauge needle 1¹ ₂-in needle, three-way stopcock • Specimen containers 3 05 13 Bedside Procedures Procedure Thoracentesis is the surgical puncture of the chest wall to aspirate fluid or air from the pleural cavity The area of pleural effusion is dull to percussion with decreased whisper or breath sounds Pleural fluid causes blunting of the costophrenic angles on chest x-ray Blunting... count) See Table 13 5 for interpretation 8 Remove the catheter and suture the skin If the catheter is inserted for pancreatitis or peritoneal dialysis, suture it in place 13 296 Clinician’s Pocket Reference, 9th Edition TABLE 13 5 Criteria for Evaluation of Peritoneal Lavage Fluid Positive Intermediate Negative >20 mL gross blood on free aspiration (10 mL in children) ≥100,000 RBC/mL 50 0 WBC/mL (if obtained... larger the diameter) Irrigation catheters (“three-way Foley”) should be larger (20–22 French) Coudé (pronounced “COO-DAY”): An elbow-tipped catheter useful in males with prostatic hypertrophy (the catheter is passed with the tip pointing to 12 o’clock) Red rubber catheter (Robinson): Plain rubber or latex catheter without a balloon, usually used for “in-and-out catheterization” in which urine is removed . mL)(eg, 5 TU PPD) • A small, short needle (2 5- , 2 6-, or 27-gauge) • 1-mL syringe • Alcohol swab Procedure 1. Skin tests for delayed type hypersensitivity (type IV, tuberculin) are the most com- monly. biopsy rather than a punch biopsy. Materials • 2-, 3-, 4-, or 5- mm skin punch • Minor procedure tray (page 240) • Curved iris scissors and fine-toothed forceps (Ordinary forceps may distort a. (#/mm 3 ) 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 Clear or Normal or Normal or Nor mal 10 50 0 (“aseptic meningitis”)