1. What is a fever?

Show answer Normal core temperature varies between 36°C and 38°C. Because we hibernate a little at night, we are cool (36°C) just before rising in the morning; after revving our engines all day, we are hot at night (38°C). A fever is a pathologic state reflecting a systemic inflammatory process. The core temperature is > 38°C but rarely > 40°C.

2. What is malignant hyperthermia?

Show answer
A rare, life-threatening response to inhaled anesthetics or some muscle relaxants. Core temperature rises > 40°C. Abnormal calcium metabolism in skeletal muscle produces heat, acidosis, hypokalemia, muscle rigidity, coagulopathy, and circulatory collapse.

3. How is malignant hyperthermia treated?

Show answer

* Stop the anesthetic.
* Give sodium bicarbonate (2 mEq/kg IV).
* Give dantrolene (calcium channel blocker at 2.5 mg/kg IV).
* Continue dantrolene (1 mg/kg every 6 hours for 48 hours).
* Cool patient with alcohol sponges and ice.

KEY POINTS: MALIGNANT HYPERTHERMIA

1. Rare, familial (autosomal dominant with variable penetrance) catastrophic response to inhaled anesthetics or muscle relaxants.
2. Mechanism: abnormal calcium metabolism in skeletal muscle.
3. Clinical manifestations: core temperature > 40°C, trismus, hypercapnia, tachycardia, tachypnea, hypertension, cardiac dysrhythmias, metabolic acidosis, hypoxemia, myoglobinuria, coagulopathy.
4. Management: halt anesthetic; administer dantrolene over 48 hours, supplemental sodium bicarbonate; actively cool patient.

4. What causes fever?

Show answer
Macrophages are activated by bacteria and endotoxin. Activated macrophages release interleukin-1, tumor necrosis factor, and interferon, which reset the hypothalamic thermoregulatory center.

5. Can fever be treated?

Show answer
Yes. Aspirin, acetaminophen, and ibuprofen are cyclooxygenase inhibitors that block the formation of prostaglandin E2 in the hypothalamus and effectively control fever.

6. Should fever be treated?

Show answer
This is controversial. No evidence suggests that suppression of fever improves patient outcome. Patients are more comfortable, however, and the surgeon receives fewer calls from the nurses.

7. Should fever be investigated?

Show answer
Yes. Fever indicates that something (frequently treatable) is going on. The threshold for inquiry depends on the patient. A transplant patient with a temperature of 38°C requires scrutiny, whereas a healthy medical student with an identical temperature of 38°C 24 hours after an appendectomy can be ignored.

8. Summarize a fever work-up.

Show answer

* Order blood cultures, urine Gram stain and culture, and sputum Gram stain and culture.
* Look at the surgical incisions.
* Look at old and current IV sites for evidence of septic thrombophlebitis.
* If breath sounds are worrisome, obtain a chest x-ray.

9. What is the most common cause of fever during the early postoperative period (1-3 days)?

Show answer
The traditional answer is atelectasis. A total pneumothorax does not cause fever, however. Why does a little atelectasis cause fever, whereas a lot of atelectasis (pneumothorax) does not? The most likely explanation is that sterile atelectasis (and early postoperative lung collapse typically is not infected) has nothing to do with fever.

10. Do surgical incisions compromise spontaneous breathing patterns?

Show answer
Yes. Vital capacity was measured in a large group of patients 24 hours after various surgical procedures. An upper abdominal incision was the worst, followed by lower abdominal incision, then (counterintuitively) thoracotomy, median sternotomy, and extremity incision.

11. Should atelectasis be treated with incentive spirometry?

Show answer
Yes-but not to avoid fever.

12. Define a wound infection.

Show answer
A wound infection contains > 105 organisms per gram of tissue. An infected incision appears erythematous (red), edematous (swollen), and tender.

13. Are certain wounds prone to infection?

Show answer
Each milliliter of human saliva contains 108 aerobic and anaerobic, gram-positive and gram-negative bacteria. All human bite wounds must be considered as contaminated. Animal bite wounds typically are less contaminated. (It is safer to kiss your dog than your fiancé[e].)

14. Do incisions become infected early after surgery?

Show answer
The incision must be examined in a patient with a fever (39°C) < 12 hours after surgery. Look for a foul-smelling, serous discharge in a particularly painful wound (all incisions hurt) with or without crepitus. Gram stain of the serous discharge for gram-positive rods confirms or excludes the diagnosis of clostridial infection.

15. Summarize the therapy for clostridial gas gangrene.

Show answer

* The wound should be opened immediately, with fluid resuscitation of the patient. The mainstay of therapy is aggressive surgical debridement of necrotic tissue (skin, muscle, fascia). Make a big hole, and do not worry about closing it.
* Give penicillin, 12 million U/day IV for 1 week.
* Hyperbaric oxygen is not helpful.

16. Are nonclostridial necrotizing wound infections a cause of concern?

Show answer
Hemolytic streptococcal gangrene, idiopathic scrotal gangrene, and gram-negative synergistic necrotizing cellulitis are distinct entities but have been lumped into the single category of necrotizing fasciitis. All require the same initial approach:

1. Fluid and electrolyte resuscitation
2. Broad-spectrum antibiotics (”triples”)
3. Aggressive surgical debridement of all necrotic tissue

17. What are triple antibiotics?

Show answer
A shotgun approach to potentially life-threatening infections when the patient is seriously ill and the surgeon is seriously concerned:

1. Gram-positive coverage (e.g., ampicillin)
2. Gram-negative coverage (e.g., gentamicin)
3. Anaerobic coverage (e.g., metronidazole [Flagyl])

To avoid overgrowth of yeast and resistant bacteria, focus on the culprit bacteria as soon as the cultures define it.
KEY POINTS: CLOSTRIDIAL VERSUS NONCLOSTRIDIAL NECROTIZING WOUND INFECTIONS

1. Clostridial infection involves underlying muscle resulting in myonecrosis or gas gangrene.
2. Nonclostridial infection involves subcutaneous fascia (also known as necrotizing fasciitis).
3. Similar management: fluid and electrolyte resuscitation, antibiotics (high-dose penicillin for clostridial infection, broad-spectrum triples for necrotizing fasciitis), and aggressive surgical debridement of necrotic tissue.

18. Give the doses for triple antibiotics.

19. Which surgical procedures predispose to wound infections?

Show answer
Gastrointestinal procedures, especially when the colon is opened.

20. When do wound infections typically occur?

Show answer
12 hours to 7 days postoperatively.

21. How is a wound infection treated?

Show answer
The wound should be opened and completely drained.

22. Is it necessary to irrigate an infected wound?

Show answer
Tap water irrigation decreases the bacterial load and promotes healing. Alcohol is toxic to tissues. Sodium hydrochlorite (Dakin solution) and hydrogen peroxide kill fibroblasts and slow epithelialization. As a rule of thumb, put nothing into a wound that you would not put in your eye.

23. When do urinary tract infections (UTIs) occur?

Show answer
The longer the urethral (Foley) catheter is in place, the more likely the infection. Urologic instrumentation at the time of surgery may accelerate the process considerably. Germs crawl up the outside of the urethral catheter, and by 5-7 days after surgery most patients harbor infected urine.

24. How is a UTI diagnosed?

Show answer
Urine culture with > 105 bacteria/mL defines a UTI. White blood cells on urinalysis are highly suspicious.

25. Name the most common late causes of postoperative fever.

Show answer
Septic thrombophlebitis (from an IV line) and occult (usually intraabdominal) abscesses tend to present ≥ 2 weeks after surgery.

References
WEB SITES

1. http://www.mhacanada.org
2. http://www.anes.ucla.edu/dept/mh.html

BIBLIOGRAPHY
1. Bansal BC, Wiebe RA, Perkins SD, Abramo TJ: Tap water for irrigation of lacerations. Am J Emerg Med 20:469-472, 2002. Medline Similar articles Full article
2. Helmer KS, Robinson EK, Lally KP, et al: Standardized patient care guidelines reduce infectious morbidity in appendectomy patients. Am J Surg 183:608-613, 2002. Medline Similar articles Full article
3. Lewis RT: Oral versus systemic antibiotic prophylaxis in elective colon surgery: A randomized study and meta-analysis send a message from the 1990’s. Can J Surg 45:173-180, 2002.
4. Singer AJ, Quinn JV, Thode HC Jr, Hollander JE, TraumaSeal Study Group: Determinants of poor outcome after laceration and surgical incision repair. Plast Reconstr Surg 110:429-435, 2002. Medline Similar articles Full article

• Postoperative fever workup
• opss sepsis 14 days
• solitary pulmonary nodule breast cancer patient
• honeymoon period bochdalek
• relation between breathlessness and total thyroidectomy
• colon surgery diverticulitis
• Hematest-positive NGT
• nonoperative management of spleen injury
• when is the parental nutrion discontinued
• grading for splenic laceration
• having a solitary nodule with calcium flecks
• how many milliequivalents in gatorade

25. Should all patients undergoing elective laparotomy receive prophylactic antibiotic coverage?

Show answer
No. Doing so would contribute to driving up the cost of antibiotics and their complication rate and devaluing formerly good drugs by rendering them useless against common flora against which they were once highly potent. Operating room nurses have always classified the kind of operation by its status with respect to microbial exposure: clean, contaminated, or septic. These categories are approximation of the microbial risk exposure, and if additionally are superimposed categories of patient resistance (higher risk associated with aging, obesity or other malnutrition, concomitant drugs, or viral or mycobacterial or neoplastic disease immune compromise), these same strata are called class I, II, and III.

26. Which abscess is the most important one to be drained?

Show answer
It is the last abscess that counts in drainage because the patient’s dramatic response is often only achieved when the last pus is drained. Draining a pelvic abscess, for example, but leaving behind a subphrenic abscess, would not result in the quenching of the inflammatory mediators of the sepsis syndrome.
27. Is postoperative fever the earliest and most frequent sign of an incisional infection? Show answer
Postoperative fevers are much more frequent than are wound infections, and the typical wound infection presents far later. The principal sources of postoperative fever are:

* Wind (atelectasis or pneumonia)
* Water (urinary tract infection)
* Walk (get your patient up and around; thrombophlebitis)
* Wound

28. Should you begin amphotericin at the first isolation of Candida species drawn from any intravenous catheter line?

Show answer
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No. Again, remember the distinction between colonization and infection, as well as the source from which the specimen is taken. The IV lines through which hyperalimentation solutions are infused make colonization possible. The presence of a fungus such as Candida species is frequent in patients who do not have an invasive fungal infection or a true candidemia. The latter might be distinguished from catheter colonization by a blood culture drawn from another source, such as a venopuncture. If evidence of any invasive fungal infection is also present (e.g., as endoscopic biopsy of inflammatory mucositis), a choice of antifungal therapies is now indicated.
Topical fungal solutions (e.g., mycostatin mouthwashes or lavage) may control the local fungal infection and may sometimes be instituted as prophylaxis in high-risk patients (e.g., patients on antirejection therapy for bone marrow or solid organ transplantation).
Systemic antifungal agents include fluconazole, caspifungin, and amphotericin.

29. Are antibiotic drug combinations always superior to a single antibiotic agent?

Show answer
Monotherapy is superior to combination antibiotic treatment regimens, but this is provable probably only in the highest-risk patients. With the carbapenem class antibiotic agents, a large multicenter clinical trial proved imipenem therapy superior to aminoglycoside and a macrolide antibiotic, with survival demonstrably superior only in the patients with the highest APACHE scores. Ertapenem monotherapy was the equivalent of ceftriaxone and metronidazole in a smaller, more recent trial.
More is not always better, and the R and S on culture reports does not translate directly to the M and M (morbidity and mortality) at the Death and Complications Conference reports. It is not just important that the effective antibiotic regimen kills the bacteria; also important are how this microbicidal effect is carried out and what effect it may have on the patient in quenching or prolonging the systemic inflammatory response.

30. Is antibody treatment of circulating endotoxin a clinically important tool?

Show answer
Not yet. The neutralization of circulating endotoxin might give a theoretic benefit to patients with sepsis, and animal studies looked promising. But antigen/antibody complexes initiate complement cascade and release of activate leukocyte products such as leukotrienes that may further augment the inflammatory process. The complexes are also filtered in the kidney where they may further impair renal function. To date, no clinical therapeutic benefit has been demonstrated for such monoclonal antibody therapy.

31. What is the role of human recombinant activated protein C in patients with sepsis?

Show answer
Of the multiple clinical trials of mediator neutralization or receptor blockade, the evidence to date seems marginally favorable only for a few, and the major response to treatment comes from early and complete control of the focus of sepsis (not the cytokine sequelae).

References
WEB SITES

1. http://www.acssurgery.com/abstracts/acs/acs0102.htm
2. http://www.medscape.com
* Search: preoperative antibiotics

BIBLIOGRAPHY
1. Bartlett JG: Intra-abdominal sepsis. Med Clin North Am 79:599-617, 1995. Medline Similar articles
2. Bernard GR, Vincent JL, Laterre PF, et al: Efficacy and safety of recombinant human activated protein C for severe sepsis. N Engl J Med 344:699, 2001.

3. Bilik R, Burnweit C, Shandling B: Is abdominal cavity culture of any value in appendicitis? Am J Surg 175:267-270, 1998.
4. Christou NV, Turgeon P, Wassef R, et al: Management of intra-abdominal infections. The case for intraoperative cultures and comprehensive broad-spectrum antibiotic coverage. The Canadian Intra-abdominal Infection Study Group. Arch Surg 131:1193-1201, 1996. Medline Similar articles
5. Ciftci AO, Tanyei FC, Buyukpamukcu N, Hicsonmea A: Comparative trial of four antibiotic combinations for perforated appendicitis in children. Eur J Surg 163:591-596, 1997. Medline Similar articles
6. Falagas ME, Barefoot L, Griffith J, et al: Risk factors leading to clinical failure in the treatment of intra-abdominal or skin/soft tissue infections. Eur J Clin Microbiol Infect Dis 15:913-921, 1996. Medline Similar articles
7. Geelhoed GW: Preoperative skin preparation: Evaluation of efficacy, timing, convenience, and cost. Infect Surg 85:648-669, 1985.

1. How common is bladder cancer?

Show answer
Approximately 54,300 new cases of bladder cancer were diagnosed in 2001 in the United States, and 12,400 patients died. The male-to-female ratio is almost 3:1.

2. What are the risk factors for bladder cancer?

Show answer
Cigarette smoking, exposure to aniline dyes or aromatic amines, phenacetin abuse, and chemotherapy (cyclophosphamide).

3. How does bladder cancer present?

Show answer
Painless hematuria (gross or microscopic). Frequency, urgency, and dysuria also may be presenting symptoms, especially for carcinoma in situ (CIS).

4. What is the most common histologic type of bladder cancer?

Show answer
Transitional cell carcinoma (TCC) makes up > 90% of bladder cancers. Other histologic types include adenocarcinoma, squamous cell carcinoma, and urachal carcinoma.

5. How is TCC of the bladder treated?

Show answer
With transurethral resection of the bladder tumor. Further treatment is determined by the pathologic stage of the disease.

6. Is CIS a less aggressive type of bladder cancer?

Show answer
No. TCC in situ is a flat but poorly differentiated tumor. It can metastasize and should be treated as an aggressive form of bladder cancer.

7. How is CIS treated?

Show answer
Immunotherapy with intravesical bacillus Calmette-Guérin (BCG) is currently the first-line treatment. Response rates to BCG approach 70%. Other intravesical agents, such as mitomycin C, are generally less effective than BCG.

8. What are the side effects of BCG?

Show answer
Mild symptoms of urinary frequency, urgency, and dysuria are common. Myalgias and low-grade fever (flulike symptoms) also occur. High or persistent fever suggests a more serious problem requiring antituberculous therapy. Rarely, death from BCG has been reported.

9. How is muscle-invasive bladder cancer treated?

Show answer
Radical cystectomy (or cystoprostatectomy in men) with some form of urinary diversion.

10. What types of urinary diversion are used with radical cystectomy?

Show answer
Diversion techniques require either a conduit or a continent reservoir. The most common is an ileal conduit. An external collection device must be worn with a conduit. Continent reservoirs are made of combinations of large and small bowel and must be emptied via the urethra or a continent stoma.

KEY POINTS: BLADDER CANCER

1. Bladder cancer presents as painless hematuria.
2. The most common histologic type is transitional cell carcinoma.
3. Carcinoma in situ of the bladder is treated with intravesical bacillus Calmette-Guérin.

11. How is metastatic bladder cancer treated?

Show answer
Metastatic bladder cancer requires chemotherapy. Most regimens include a platinum-based agent.

12. Can invasive bladder cancer be cured without removal of the entire bladder?

Show answer
This issue is controversial. Some cancers may be suitable for partial cystectomy (i.e., tumors isolated in the dome of the bladder). Investigations are ongoing to evaluate transurethral resection of bladder tumor plus radiation and chemotherapy to try to preserve the bladder in invasive TCC.

1. What causes mitral stenosis?

Show answer
Rheumatic fever.

2. Which gender most commonly gets mitral stenosis?

Show answer
Women by a ratio of 3:2.

3. What are the physical findings of mitral stenosis?

Show answer
On ascultation, an opening snap and a diastolic murmer are heard best at the apex.

4. How is the diagnosis confirmed?

Show answer
By echocardiography, preferably transesophageal echocardiography (TEE).

5. What is the Gorlin formula?

Show answer
A formula used to calculate the area of a heart valve. In simplified terms:

6. What is the normal size of the mitral valve?

Show answer

* The normal cross-sectional area is 4-6 cm2.
* Mild mitral stenosis is < 2 cm2.
* Severe mitral stenosis is < 1 cm2.

7. What is the pathophysiology of mitral stenosis?

Show answer
Increased left atrial pressure is necessary to push blood through a stenotic mitral valve from the left atrium into the left ventricle. Increased left atrial pressure is transmitted retrograde into the pulmonary veins and pulmonary capillaries and ultimately into the pulmonary arteries. It gives the patient a sensation of dyspnea. A left atrial pressure of approximately 25 mmHg increases pulmonary capillary pressure enough to produce pulmonary edema.
Example: To maintain adequate left ventricular filling across a 1.5-cm2 valve, a pressure gradient of 20 mmHg is required. With a normal left ventricular end-diastolic pressure of 5 mmHg, a 20-mmHg gradient produces a left atrial pressure of 25 mmHg. Left atrial pressure rises even further as flow across the valve increases (increased cardiac output). This high left atrial pressure backs up and floods the lungs (pulmonary edema).

8. What is the main symptom of mitral stenosis?

Show answer
Dyspnea on exertion (DOE).

9. What hemodynamic conditions precipitate symptoms in patients with mitral stenosis?

Show answer
Tachycardia: Because blood flows through the mitral valve during diastole, a shorter diastole (tachycardia) means less time for blood to move through the stenotic mitral valve, which decreases stroke volume.

Loss of atrial kick: As left atrial pressure increases, the left atrium stretches bigger and the normally organized atrial impulse becomes chaotic (i.e., atrial fibrillation). Increased pressure is required to move blood through the stenotic valve. Loss of presystolic atrial contraction may decrease left ventricular filling by as much as 30%.

Show answer

1. Hemoptysis from severe pulmonary venous congestion
2. Thromboembolism in patients in atrial fibrillation
3. Endocarditis
4. Pulmonary hypertension and right heart failure

KEY POINTS: MITRAL STENOSIS

1. Mitral stenosis is caused by rheumatic fever.
2. Physical findings include auscultation of an opening snap and a diastolic murmur, heard best at the apex.
3. Mitral commissurotomy and mitral valve replacement are the two operations that may be done for mitral valve stenosis.

11. Why does mitral stenosis cause pulmonary hypertension?

Show answer

* Retrograde transmission of increased left atrial pressure
* Reflex pulmonary vasoconstriction initiated by left atrial distention
* Hypertrophy of the pulmonary arteries, leading to remodeling of the pulmonary vasculature

12. What is the medical therapy of mitral stenosis?

Show answer

* Beta blockers slow the ventricular rate to about 60 bpm.
* Digoxin slows the ventricular rate (by slowing atrioventricular nodal conduction) in patients with atrial fibrillation.
* Diuretics (furosemide) relieves pulmonary edema.
* Warfarin (Coumadin) is used if the patient is in atrial fibrillation.

13. What is the natural history of mitral stenosis?

Show answer
The survival with moderate mitral stenosis is approximately 50% at 10 years.
14. What are the indications for mechanical intervention in mitral stenosis? Show answer

* Symptomatic patients with moderate-to-severe mitral stenosis
* Asymptomatic patients with a mitral valve area < 1 cm2

15. What is the procedure of choice for mitral stenosis?

Show answer
If the patient has mobile valve leaflets, no calcium in the valve leaflets, and minimal concurrent mitral regurgitation, then balloon valvuloplasty with a catheter may be an option.

16. Which patients may be appropriate candidates for balloon valvuloplasty?

Show answer
Again, this can be a tough call, but patients may be candidates if they are without calcification of the mitral annulus or leaflets, have little or no mitral regurgitation, and have little or no fusion of the mitral chordae tendineae.

17. What are the results of balloon valvuloplasty?

Show answer

* Mortality rate < 1%.
* Initial success can be as high as 95% in properly selected patients.
* Valve area may increase to 2 cm2.
* < 90% event-free (you and your patient do not want "events") survival at 7 years, again in properly selected patients.

<

strong>18. Which operations may be done for mitral stenosis?

Show answer

* Mitral commissurotomy: The mortality rate is < 2%, and recurrence of mitral stenosis is 2% per year.
* Mitral valve replacement: The mortality rate is 6%.

7. Are vital signs important?

Show answer
Yes. They are vital. If heart rate and blood pressure are on the wrong side of 100 (heart rate > 100 beats/min, systolic blood pressure < 100 mmHg), watch out! Tachypnea (respiratory rate >16) reflects either pain or systemic acidosis. Fever may develop late, particularly in the immunosuppressed patient who may be afebrile in the face of florid peritonitis.

8. What is rebound?

Show answer
The peritoneum is well innervated and exquisitely sensitive. It is not necessary to hurt the patient to elicit peritoneal signs. Depress the abdomen gently and release. If the patient winces, the peritoneum is inflamed (rebound tenderness).

9. What is mittelschmerz?

Show answer
Mittelschmerz is pain in the middle of the menstrual cycle. Ovulation frequently is associated with intraperitoneal bleeding. Blood irritates the sensitive peritoneum and hurts.

10. What do bowel sounds mean?

Show answer
If something hurts (e.g., a sprained ankle), the patient tends not to use it. Inflamed bowel is quiet. Bowel contents squeezed through a partial obstruction produce high-pitched tinkles. Bowel sounds are notoriously unreliable, however.

11. Explain the significance of abdominal distention.

Show answer
Distention may derive from either intraenteric or extraenteric gas or fluid (worst of all, blood). Abdominal distention is always significant and bad.

12. Is abdominal palpation important?

Show answer
Yes. Remember, the patient is (or should be) the surgeon’s friend. There is no need to cause pain. Palpation guides the surgeon to the anatomic zone of most tenderness (usually the diseased area). It is best to start palpation in an area that does not hurt. Rectal (test stool for blood) and pelvic examinations localize pathology further.

13. What is Kehr’s sign?

Show answer
The diaphragm and the back of the left shoulder enjoy parallel innervation. Concurrent left upper quadrant and left shoulder pain indicate diaphragmatic irritation from a ruptured spleen or subdiaphragmatic abscess.

14. What is a psoas sign?

Show answer
Irritation of the retroperitoneal psoas muscle by an inflamed retrocecal appendix causes pain on flexion of the right hip or extension of the thigh.

1. What are the clinical manifestations of pulmonary tuberculosis?

Show answer
They can be almost anything or nothing (it has been stated that if you know tuberculosis, you know all of medicine), but the most common symptoms and signs are chronic fever; weight loss; night sweats; and cough, sometimes with hemoptysis. Chest radiograph typically shows upper lobe infiltrates, with or without cavitation, and can be misdiagnosed as a neoplastic process. HIV-positive or immunocompromised patients usually have mediastinal adenopathy, pleural effusions, and a miliary pattern.

2. How is the diagnosis of pulmonary tuberculosis made?

Show answer
Positive acid-fast bacilli (AFB; “red snappers”) smear in sputum sample; sensitivity improves with bronchoalveolar lavage (BAL) specimens. Culture growth will identify specific organism (i.e., atypicals) as well as drug sensitivity (watch out for multidrug resistance [MDR]).

3. What is the current medical treatment for active tuberculosis?

Show answer
Initial therapy consists of a 6-month regimen with isoniazid, rifampin, and pyrazinamide for the first 2 months, and then isoniazid and rifampin for another 4 months. With this schedule, 95% of patients have tuberculosis-negative sputum at the end of therapy. Partial responders should receive therapy for longer than 6 months, and those with MDR-TB may receive ethambutol or streptomycin.

4. What are the indications for surgery in patients with tuberculosis?

Show answer
Surgery is indicated for complications of the disease. The most common surgical indication in the United States is MDR-TB with destroyed lung and persistent cavitary disease. This lung tissue is resistant to drug penetration and can also “spill” organsims into healthy lung tissue. Other indications include hemoptysis, exclusion of lung cancer, bronchial stenosis, bronchopleural fistula, middle lobe syndrome, or mycobacterium other than tubercle bacilli (MOTT).

5. What is MOTT, and what is the role of surgery with this disease?

Show answer
Atypical mycobacterial infections, nontuberculosis mycobacterial infections, and infection with mycobacteria other than tuberculosis are synonyms. The most common of these organisms is the Mycobacterium avium complex (MAC). Others include M. chelonae and abscesses, M. kansaii, M. fortuitum, and M. xenopi. MAC typically produces fibrocavitary disease of the upper lobes or the middle lobe or lingula of thin, white women. Surgery is indicated for localized disease, and in combination with drug therapy, it results in sputum conversion in ≥ 95% of patients with relapse rates of < 5%. Other indications for surgery are the same as for regular tuberculosis.

1. What is hypertonic saline?

Show answer
Normal saline is 0.9% sodium chloride. Hypertonic saline is 7.5% sodium chloride (eight times as concentrated as normal saline).

KEY POINTS: ION CONCENTRATIONS IN CRYSTALLOID SOLUTIONS

1. ½ NS or 0.45% NaCl: 77 mEq of Na+, 77 mEq of Cl-
2. NS or 0.9% NaCl: 154 mEq of Na+, 154 mEq of Cl-
3. Hypertonic NS or 7.5% NaCl: 1283 mEq of Na+, 1283 mEq of Cl-
4. Lactated Ringer’s: 130 mEq of Na+, 110 mEq of Cl-, 38 mEq of lactate, 4 mEq of K+, and 3 mEq Ca+

2. What is hypertonic saline good for?

Show answer
Resuscitation. The initial hypothesis was that a little hypertonic saline would pull extravascular water into the intravascular compartment, rapidly restoring volume. It now appears that an osmotic jolt (even a transient jump from 140 to 180 mOsm) would pacify circulating neutrophils so that they do not stick to the endovasculature and provoke posttraumatic inflammation.

3. Is hypertonic saline good for anything else?

Show answer
Pacification of “primed” neutrophils should decrease the risk of posttraumatic multiple organ failure.

4. How do you convert 1 g of sodium into milliequivalents (mEq)?

Show answer
Divide by the atomic weight of sodium:

1g (1000 mg) of sodium ÷ 23 = 43.5 mEq

5. How many mEq of sodium are in 1 teaspoon of salt?

Show answer
104 mEq (or 2400 mg).

6. How many mEq of sodium are in an 8-oz bottle of Gatorade?

Show answer
5 mEq.

7. How much does a 40-lb block of salt cost?

Show answer
$3.40 at the feed store.

8. What is the electrolyte content of IV fluids?

Show answer
See Table 7-1.

Table 7-1. ELECTROLYTE CONTENT OF INTRAVENOUS FLUIDS

*Lactate is converted immediately to bicarbonate.

9. How do these concentrations relate to body fluid and electrolyte compartments?

Show answer
See Table 7-2.
Table 7-2. ELECTROLYTE CONCENTRATIONS IN BODY FLUIDS

10. What are the daily volumes (mL/24 h) and electrolyte contents (mEq/L) of body secretions for a 70-kg medical student?

Show answer
See Table 7-3.
Table 7-3. DAILY VOLUMES AND ELECTROLYTE CONTENTS OF BODY SECRETIONS

*See question 6.

11. Are sweat glands responsive to aldosterone? Can they be trained?

Show answer
Yes and yes. Archie Bunker’s sweat contains 100 mEq/L sodium, whereas an Olympic marathon runner retains sodium (sweat sodium may be as low as 25 mEq/L).

12. Is Gatorade really just flavored athlete’s sweat?

Show answer
Yes.

13. What are the daily maintenance fluid and electrolyte requirements for a 70-kg medical student?

14. Does the routine postoperative patient require IV sodium or potassium supplementation? Routine serum electrolyte testing?

Show answer
No and no.

15. Can a patient with a good heart and kidneys overcome all but the most woefully incompetent fluid and electrolyte management?

Show answer
Yes.

16. Can one throw a healthy medical student into congestive heart failure by IV infusion of 100 mL of 5% dextrose in saline solution per kg per hour?

Show answer
No. One will simply be ankle-deep in urine.

17. What is subtraction alkalosis?

Show answer
Vigorous nasogastric suction of a patient with a lot of gastric acid eliminates hydrochloric acid, leaving the patient alkaloti

c.
18. Which electrolyte is most useful in repairing a hypokalemic metabolic alkalosis?

Show answer
Chloride.

19. List the best indicators of a patient’s volume status.

Show answer

* Heart rate
* Blood pressure
* Urine output
* Big-toe temperature

20. Does a warm big toe indicate a hemodynamically stable patient?

Show answer
Most likely. The vascular autoregulatory ability of a young healthy patient is huge. The carotid and coronary circulations are maintained until the bitter end. Conversely, if the patient’s big toe is warm and perfused, the patient is stable.

21. What is the minimal adequate postoperative urine output?

Show answer
0.5 mL/kg/h.

22. What is a typical postoperative urine sodium?

Show answer
< 20 mEq/L.

23. Why?

Show answer
Surgical stress prompts mineralocorticoid (aldosterone) secretion so that the normal kidney retains sodium.

24. Explain paradoxical aciduria.

Show answer
Postoperative patients, by virtue of nasogastric suction (loss of gastric acid), blood transfusions (the citrate in blood is converted to bicarbonate), and hyperventilation (decreased Pco2), are typically alkalotic. Patients also are stressed, and their kidneys retain sodium and water. The renal tubules must exchange some other cations for the retained sodium. The kidney chooses to exchange potassium and hydrogen ions. Even in the face of systemic alkalosis, the postoperative kidney absorbs sodium and excretes hydrogen ions, producing a paradoxical aciduria.
KEY POINTS: MECHANISMS OF PARADOXICAL ACIDURIA

1. Nasogastric suction or refractory vomiting results in loss of gastric acid.
2. Physiologic stress promotes renal retention of sodium and water.
3. To hold on to sodium, the kidney must release other cations (potassium and hydrogen).
4. Counterintuitively, the kidney will release hydrogen ions to keep sodium, resulting in acidic urine.

25. What is third spacing?

Show answer
Hypotension and infection prime neutrophils (CD11 and CD18 receptor complexes), promoting adherence to vascular endothelial cells. Subsequent activation of adherent neutrophils spews out proteases and toxic superoxide radicals, blowing big holes in the vascular lining. Water and plasma albumin leak through the holes. The volume pulled out of the vascular space into the third space of the interstitial and hollow viscus (gut) creates relative hypovolemia and requires additional fluid replacement.

26. What is a Lasix sandwich?

Show answer
25% albumin followed by 20 mg of furosemide (Lasix) IV. If the patient is edematous, the IV albumin theoretically sucks water osmotically out of the interstitial third space. As the excessive water enters the vascular compartment, Lasix produces a healthy diuresis. In most intensive care unit patients, however, the infused albumin rapidly equilibrates across the damaged vascular endothelium. No additional water is pulled into the blood volume. Although surgeons often order Lasix sandwiches, they probably work only in healthy patients who do not need them.

References
BIBLIOGRAPHY
1. Brown MD: Evidence-based emergency medicine: Hypertonic versus isotonic crystalloid for fluid resuscitation in critically ill patients. Ann Emerg Med 40:113-114, 2002. Medline Similar articles Full article
2. Bunn F, Roberts I, Tasker R, Akpa E: Hypertonic versus isotonic crystalloid for fluid resuscitation in critically ill patients. Cochrane Database Syst Rev (1):CD002045, 2002. Full article
3. Greaves I, Porter KM, Revell MP: Fluid resuscitation in pre-hospital trauma care: A consensus view. J R Coll Surg Edinb 47:451-457, 2002. Medline Similar articles
4. Traber DL: Fluid resuscitation after hypovolemia. Crit Care Med 30:1922, 2002. Medline Similar articles

1. When and where was the first liver transplant performed?

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Dr. Thomas Starzl performed the first operation on March 1, 1963, at the University of Colorado in Denver.

2. Is liver transplantation considered a safe and effective operation?

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Yes. Although still a major operation with significant risks, patient and graft survival have continuously improved. One-year survival should be well over 90% in major centers.

3. What are the most common indications for liver transplantation in the United States?

Show answer
Noncholestatic cirrhosis characterizes > 50% of the recipients. This group includes those with viral hepatitis, alcoholic cirrhosis (Laennec’s), and Budd-Chiari syndrome. Cholestatic cirrhosis makes up an additional 15%, with primary sclerosing cholangitis (PSC) and primary biliary cirrhosis heading this group. Other indications include biliary atresia, acute hepatic necrosis, malignant neoplasms, and metabolic disease.

4. Has the most common disease requiring transplantation shifted over the years?

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Yes. The largest percentage of people now being transplanted have hepatitis C. There are also more retransplants performed because some diseases such as hepatits C and PSC can recur in transplanted livers.

5. How is the waiting list run?

Show answer
Changes have been made to the list so that the sickest patients get transplanted first. New scoring systems (Mayo End-stage Liver Disease [MELD] score) have been devised to give more weight to objective markers of illness rather than the more subjective medical criteria used in the past. This point system has also minimized the importance of time spent on the waiting list. The goal of these changes is to reduce waiting list mortality.

6. What are some of the recent advances in liver transplant surgery?

Show answer
Operative techniques have improved such that some liver transplant recipients do not require a stay in the intensive care unit, venovenous bypass, or external biliary drainage, and operative times are shorter (4-5 hours). Improved immunosuppression medications have reduced rejection rates and side effects.

7. How long can a liver be kept “on ice”?

Show answer
Optimal cold ischemia should be < 12 hours.

8. What are some common postoperative complications of liver transplantation?

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Postoperative bleeding, infection, and biliary complications are the most common. Primary nonfunction (< 5%) and early hepatic artery thrombosis (5%) are less common, but they usually require an urgent retransplant.

9. What is the “piggy-back” technique?

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This is a technique in which the recipient’s sick liver is carefully resected off of his or her vena cava, which is left in situ. The upper donor cava is then sewn to a common cuff of native hepatic veins. The donor’s lower cava is ligated. Using this method, it is possible to do the complete transplant with minimal if any vena caval occlusion, resulting in less intraoperative hemodynamic instability.

10. Is living-donor liver transplantation an option?

Show answer
Yes. Initially used in the pediatric population using an adult left lateral segment graft, this procedure has evolved into fairly common practice. The Far East has had a large number of adult-to-adult left lobe graft series. Elsewhere, this has been replaced with a right lobe donor operation. Both the donor and recipient liver lobes quickly regenerate to normal size. Results in experienced centers mimic those of cadaveric transplant with similar patient survival, albeit at higher complication and retransplant rates.
KEY POINTS: LIVER TRANSPLANTATION

1. The most common indication for liver transplantation in the United States is noncholestatic cirrhosis.
2. Optimal cold ischemia time for the liver is < 12 hours.
3. Transjugular intrahepatic portosystemic shunts can be used in potential transplant recipients as a bridge to transplantation.

11. How have transjugular intrahepatic portosystemic shunts (TIPS) improved this field of surgery?

Show answer
TIPS can be used in potential transplant recipients as a bridge to transplantation. This procedure is very effective in controlling portal hypertension without the need for a major abdominal operative shunt. A prior portocaval shunt does complicate a liver transplant, but it is not a contraindication to liver transplantation.

15. Is GERD better treated in the long term by PPI therapy or Nissen fundoplication?

Show answer
PPIs really work in resolving esophagitis and eliminating symptoms of GERD, but the long-term side effects are not fully known. Fundoplication potentially frees the patient from daily medicine (this has been challenged recently) and may cause morbidity in ≤ 10% of patients.

16. Should a Nissen fundoplication be performed by laparoscopy or laparotomy?

Show answer
The same procedure can be accomplished by either approach. Postoperative morbidity and mortality is comparable. The distinct advantages of laparoscopy are less postoperative pain, shorter hospitalization, and earlier return to work.

17. Can this disease be treated by other minimally invasive means?

Show answer
Yes. Other endoscopic methods include:

* Endoluminal suturing
* Radiofrequency treatment of the LES
* Injection of bulk-forming agents around the LES

References
WEB SITE
http://www.emedicine.com/med/topic857.htm
BIBLIOGRAPHY
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2. DeMeester TR, Peters JH, Bremner CG, Chandrasoma P: Biology of gastroesophageal reflux disease: Pathophysiology relating to medical and surgical treatment. Annu Rev Med 50:469-506, 1999. Medline Similar articles
3. Hinder RA, Filipi CJ, Wetscher G, et al: Laparoscopic Nissen fundoplication is an effective treatment for gastroesophageal reflux disease. Ann Surg 220:472-481, 1994. Medline Similar articles
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5. Lord RV, Kaminski A, Oberg S, et al: Absence of gastroesophageal reflux disease in a majority of patients taking acid suppression medications after Nissen fundoplication. J Gastrointest Surg 6:3-9, 2002. Medline Similar articles Full article
6. Peters JH, DeMeester TR (eds): Minimally Invasive Surgery of the Foregut. St. Louis, Quality Medical Publishing, 1994.
7. Roy-Shapira A, Stein HJ, Scwartz D, et al: Endoluminal methods of treating gastroesophageal reflux disease. Dis Esophagus 15:132-136, 2002. Medline
8. Spechler SJ: Comparison of medical and surgical therapy for complicated gastroesophageal reflux disease in veterans. N Engl J Med 326:786-792, 1992. Medline Similar articles
9. Spechler SJ, Lee E, Ahnen D, et al: Long-term outcome of medical and surgical therapies for gastro-esophageal reflux disease: follow-up of a randomized controlled trial. JAMA 285:2331-2338, 2001.
10. Spivak H, Lulcuk S, Hunter JG: Laparoscopic surgery of the gastroesophageal junction. World J Surg 23:356-367, 1999. Medline Similar articles
11. Triadafilopoulos G, DiBaise JK, Nostrant TT, et al: The Stretta procedure for the treatment of GERD: 6 and 12 month follow-up of the U.S. open label trial. Gastrointest Endosc 55:149-156, 2002.
12. Trus TL, Laycock WS, Waring JP, et al: Improvement in quality of life measures after laparoscopic antireflux surgery. Ann Surg 229:331-336, 1999. Medline Similar articles Full article
13. Watson DI, Jamieson JG, Pike GK, Davies N, et al: Prospective randomized double-blind trial between laparoscopic Nissen fundoplication and anterior partial fundoplication. Br J Surg 86:120-130, 1999.