مواقع اعضاء هيئة التدريس | KSU Faculty
SINGLE ANSWER
1.Which of the following statements is true concerning protein/amino acid metabolism in man?
A.The major source of amino acids is breakdown of circulating proteins.
B.The recommended daily allowance for protein may triple in critically ill patients.
C.Urinary nitrogen losses will approach 0 in the face of protein starvation.
D.Positive nitrogen balance refers to a decrease in nitrogen taken into the body versus the amount of nitrogen lost.
Answer: B
About 15% of the total body weight is made up of proteins, about half of which are intracellular and half extracellular. In man and other animals, dietary protein is the source of most amino acids. Intestinal absorption is the only physiological pathway by which the body obtains exogenous amino acids. Digestion of ingested protein provides free amino acids that are absorbed by the small intestine and transported to the liver where they can be incorporated into new proteins or other biosynthetic products. Excess amino acids are degraded and their carbon skeleton is oxidized to produce energy or it is incorporated into glycogen or into free fatty acids. In addition to the metabolism of dietary amino acids, the existing proteins in the cell are continuously recycled, such that total protein turnover in the body is about 300 g/day.
Vertebrates cannot reutilize nitrogen with 100% efficiency; therefore, obligatory nitrogen losses occur, mainly in the urine. Urinary nitrogen losses will diminish when individuals are fed a protein-free diet, but will never become 0 because of the body’s inability to completely reutilize nitrogen. In stressed patients, this ability to adapt to starvation is compromised such that proteolysis of body proteins continues at a substantial rate. This increases the amount of obligatory nitrogen losses which are accentuated by the catabolic disease states. This results in a negative nitrogen balance in which the amount of nitrogen taken in by the patient is exceeded by the amount of nitrogen lost in the urine, stool, skin, wounds, and fistula drainage.
2.A 59-year-old trauma patient has suffered multiple septic complications including severe pneumonia, intraabdominal abscess, and major wound infection. He has now developed signs of multisystem organ failure. Which of the following statements is true concerning necessary changes to be made in his nutritional management?
a. Carbohydrate load should be reduced in the face of respiratory failure.
b. In patients with renal failure, protein intake should be increased.
c. During hemodialysis protein intake should be limited to the same extent.
d. In patients with hepatic failure, carbohydrate load should be increased.
Answer: A
The most severe complication of sepsis is multiple system organ dysfunction syndrome, which may result in death. The development of organ failure requires changes in the nutritional requirements and creates special feeding problems. A problem associated with systemic infection is oxygenation and elimination of carbon dioxide. Most of the enteral and parenteral formulas used to provide nutritional support for critically ill patients contain large amounts of carbohydrate, which generate large amounts of carbon dioxide following oxygenation. Such a large CO2 load may worsen pulmonary function or may delay weaning from the respirator. If this factor becomes a problem, the carbohydrate load should be reduced to 50% of metabolic requirements and fat emulsion administered to provide additional calories. When renal failure becomes progressive, the use of hemodialysis minimizes the effect of uremia superimposed on the metabolism of sepsis. Metabolic studies in patients with acute and chronic renal failure have limited the intake of nonessential amino acids, in an attempt to lower urea production. Proteins of high biologic value, but in much smaller quantities than usually given, are administered along
with adequate calories, usually in the form of glucose. When enteral feedings are not feasible, a central venous infusion of an essential amino acid solution and hypertonic dextrose provides calories and a small quantity of nitrogen to reduce protein catabolism while simultaneously controlling the rise in BUN. During dialysis, protein intake is liberalized, but the BUN should still be maintained below 100 mg/dl. Hepatic dysfunction is a common manifestation of septicemia. The carbohydrate load is usually reduced to consist of no more than 5% of metabolic requirements, and the additional calories should be provided as fat emulsion. If encephalopathy develops, protein load should also be reduced0.
3.Which of the following statements is true concerning excessive scarring processes?
a. Keloids occur randomly regardless of gender or race.
b. Hypertrophic scars and keloid are histologically different.
c. Keloids tend to develop early and hypertrophic scars late after the surgical injury.
d. Simple reexcision and closure of a hypertrophic scar can be useful in certain situations such as a wound closed by secondary intention
Answer: D
True keloids are uncommon and occur predominantly in dark skinned people with a genetic predisposition for keloid formation. In most cases, the gene appears to be transmitted as an autosomal dominant pattern. The primary difference between a keloid and a hypertrophic scar is that a keloid extends beyond the boundary of the original tissue injury. It behaves as a tumor and extends into or invades the normal surrounding tissue creating a scar that is larger than the original wound. Histologically, keloids and hypertrophic scars are similar. Both contain an overabundance of collagen. Although the absolute number of fibroblasts is not increased, the production of collagen continually out paces the activity of collagenase, resulting in a scar of ever increasing dimensions. Hypertrophic scars respect the boundaries of the original injury and do not extend into normal unwounded tissue. There is less of a genetic predisposition, but hypertrophic scars also occur more frequently in Orientals and the Black population. They are often seen on the upper torso and across flexor surfaces. Some improvement in a keloid can be obtained with excision followed by intra-lesional steroid injection. However, the resulting scar is unpredictable and potentially worse. Reexcision and closure should, however, be considered for hypertrophic scars, if the condition of closure can be improved. This is especially pertinent for wounds that originally healed by secondary intention or that are complicated by infection. Keloids typically develop several months after the injury and rarely, if ever, subside. Hypertrophic scars usually develop within the first month after wounding and often subside gradually.
4. Which of the following statements is true concerning complications of blood transfusions?
a. Immediate hemolytic transfusion reactions are caused by major ABO blood group incompatibility.
b. Nonhemolytic transfusion reactions are usually due to RH incompatibility and are therefore more common in women of childbearing age.
c. The most common complication of massive blood transfusion is dilutional thrombocytosis.
d. Routine calcium supplementation is necessary during most massive transfusion episodes
Answer: A
Immediate hemolytic reactions are usually caused by blood group ABO incompatibility although they may be caused by antigens of other blood group systems on the transfused red blood cells. The clinical manifestations revolve around the antigen on the red blood cell stroma and the antibody in the patient’s serum, and include production of bradykinin, compliment activation, release of vasoactive agents from platelets, and initiation of systemic clotting. Chills and fevers, chest pain and lumbar pain, tachycardia and hypotension in the conscious patient, and often diffuse bleeding in the anesthetized, unconscious patient constitute this syndrome. Although reaction occurs immediately, death related to the syndrome is uncommon, unless associated with a transfusion of more than 100 ml of blood. Death usually occurs from acute renal failure or hemorrhage due to DIC.
Nonhemolytic reactions occur with the frequency of 1 to 2% of all transfusions and consist primarily of chills and fevers during the transfusion or in the first 2 to 3 hours after the transfusion is complete. Mechanism of these reactions includes the presence of antibodies to white blood cell antigens in the transfused blood, especially in the multitransfused or multiparous patient. Massive transfusion complications relate to the rate and volume of blood transfused. The most common complication is dilutional thrombocytopenia. Factor deficiency of the labile factors V and VIII rarely is of sufficient magnitude to result in problems with hemostasis. For hypocalcemia to occur with massive transfusion, citrated blood must be administered, one unit every five minutes. Routine empiric calcium supplementation is unnecessary during most massive transfusion episodes. Conversely, hypothermia is clearly a problem, especially when associated with massive transfusion during complex intraoperative procedures such as thoracoabdominal aneurysm resection.
Other complications that can occur:
-circulatory overload in patients with congestive heart failure if given rapidly , so should be infused slowly 3-4 hrs , and iv furosemide should be given between units.
--------------------------------------------------------------------------------------------------------------
5.A diabetic develops a severe perineal infection with skin necrosis, subcutaneous crepitance, and drainage of a thin, watery, grayish and foul-smelling fluid. About Management all true except:
a. Gram stain of the fluid, which will likely demonstrate multiple bacteria including predominantly gram-positive rods
b. A CT scan is indicated in a stable patient to define the extent of the disease
c. Broad spectrum antibiotics followed with prompt extensive debridement is indicated
d. A safe guideline is to resect all infected necrotic tissue so that a several centimeter margin of grossly normal, healthy tissue can be achieved
e. A colostomy is of little benefit in this situation
Answer: e
The presence of severe perineal infection (referred to as Fournier gangrene when this process involves the perineum and scrotum in males) is associated with a continued high mortality despite aggressive and appropriate therapy. The clinical description provided would suggest an underlying soft tissue necrosis. In a stable patient radiologic studies including a CT scan to define the extent of the disease and the presence of pelvic infection is indicated. Gram stain will likely show evidence of polymicrobial organisms but the presence of Clostridia marked by gram-positive rods would suggest involvement with this organism. Prompt, aggressive and extensive debridement to remove all devitalized and affected tissue and the addition of broad spectrum antibiotics, fluid resuscitation, hemodynamic monitoring, and nutritional support would appear to afford the patient the best chance of survival. The clearest guidelines to determine the limits of resection involve removal of clearly infected, necrotic tissue so that margins several centimeters into grossly normal, healthy tissue are achieved. Because the entire perineal region and buttocks are frequently involved in these patients, performance of a fecal stream diversion by means of a colostomy often provides improved wound care and patient management, although it is not invariably a positive outcome.
6.If a necrotizing soft tissue infection is considered, all true except:
a. Empiric administration of antibiotics active against gram-positive, gram-negative, and anaerobic bacteria
b. Due to usually resistant species, penicillin is not indicated
c. Immediate operative intervention and aggressive resection of all involved tissues is mandatory
d. The use of hyperbaric oxygen has not been demonstrated to be clearly advantageous
Answer: B
Identification of a necrotizing, soft tissue infection mandates immediate operative intervention with aggressive resection of all involved tissues and empiric administration of antibiotics active against gram-positive, gram-negative, and anaerobic bacteria. In most cases, this involves the use of several antimicrobial antibiotics in combination. Because of concern in all cases for the presence of Clostridia infection, high doses of aqueous penicillin G are administered. Gram-positive organisms are treated with vancomycin or a semisynthetic penicillin and gram-negative organisms are treated with an aminoglycoside or a monobactam. Anaerobic coverage is typically achieved by use of metronidazole of clindamycin. The use of hyperbaric oxygen therapy is controversial and unfortunately due to the rarity of the disease, prospective randomized data is not available so that the literature remains without controlled trials demonstrating any additional benefits derived from hyperbaric oxygen therapy.
-----------------------------------------------------------------------------------------------------------------
7.Wounds are classified according to the likelihood of bacterial contamination. Which of the following statements is false concerning wound classifications?
a. A clean-contaminated wound would be that associated with an elective colon resection with adequate mechanical and antibiotic bowel preparation
b. A contaminated wound would include a resection of obstructed bowel with gross spillage of intestinal contents
c. In a clean wound, no viscus is entered.
d. Antibiotic prophylaxis should be administered for all wounds.
Answer: D
Wounds are classified under three classes according to the likelihood of bacterial contamination: 1) clean (no viscus is entered; e.g., herniorrhaphy); 2) clean-contaminated (minimal contamination; e.g., elective colon resection with adequate mechanical and antibiotic bowel preparation, and 3) contaminated (heavily contaminated surgery; e.g., resection of unprepared, obstructed bowel with gross spillage of intestinal contents or stool, drainage of abscesses, debridement of traumatic neglected wounds). Antibiotic prophylaxis generally should be administered for class 2 and 3 types of wounds, but patients undergoing clean surgery do not always require antimicrobial antibiotic prophylaxis. An exception to this tenet involves cases in which a prosthetic material may be used (artificial joint, heart valve, tissue patch).
-----------------------------------------------------------------------------------------------------------------
8.which of The following statements is false concerning necrotizing fascitis.
a. Mortality rates as high as 40-50% can be expected.
b. The infection involves only the superficial fascia, sparing the deep muscular fascia.
c. An impaired immune system is a common factor predisposing to this condition.
d. The infection is usually polymicrobial.
e. Necrotizing fascitis is most likely to develop in the face of impaired fascial blood supply.
Answer: B
Necrotizing fascitis is an uncommon infection of the deep and superficial fascia that is associated with mortality as high as 40% in many series. Although many underlying disease processes predispose patients to necrotizing fascitis, three common factors are almost invariably present: 1) impairment of the immune system; 2) compromise of fascial blood supply, and 3) the presence of microorganisms that are able to proliferate within this environment. Infections of this type are usually polymicrobial in nature, with gram-positive organisms such as staphylococci and streptococci, gram-negative enteric bacteria, and gram-negative anaerobic being frequently identified. These polymicrobial cultural results are assuredly indicative of the occurrence of a synergistic process, perhaps in large part accounting for the severity of these infections. Some microorganisms possess virulence factors that, in conjunction with an underlying host predisposition, allow this disease process to occur without dependence on other bacteria. Examples of such bacteria include Clostridium, Pseudomonas, and Aeromonas. In these patients, the process is often fulminant and is frequently associated with cellulitis, myositis, fascitis, and bacteremia with attendant high mortality
---------------------------------------------------------------------------------
9.A 67-year-old male presents with an intraabdominal abscess secondary to perforated sigmoid diverticulitis. WHICH OF The following statements is false concerning his intraabdominal abscess.
a. Culture will likely reveal a solitary organism.
b. Both aerobic and anaerobic are encountered in about 80-90%% of specimens.
c. The most common aerobic will be likely E. coli and other gram-negative enteric bacilli.
d. The most common anaerobic will be a Bacteroides species
Answer: A
Typically an intraabdominal infection results in perforation of a hollow viscus and the ensuing contamination of a normally sterile peritoneal cavity. The normal bacterial flora found in that particular location of the alimentary tract thus determines the initial inoculum. In parallel with the overall quantity of microorganisms, (both aerobes but predominantly anaerobes) perforations of the lower small bowel and colon produce a high frequency of infections that contain anaerobic microorganisms. Certain predictable patterns of bacterial islets are found, but on average four to five islets occur in patients with established intraabdominal infection, more than half of which are anaerobes. Both aerobes and anaerobes are encountered in 80% to 90% of specimens. Commonly encountered aerobes isolated are E. coli and other gram-negative enteric bacilli such as Enterobacter, Klebsiella. Among the anaerobes, Bacteroides species (especially B. fragilis, Clostridium), and anaerobic cocci are most consistently isolated.
-----------------------------------------------------------------------------------------------------------------
10.which of The following statements is true concerning gram-negative bacterial sepsis:
a. Mortality due to this condition has almost been eliminated due to therapeutic intervention. with antibiotics, aggressive hemodynamic monitoring and fluid resuscitation
b. Recent series have noted a decrease in the incidence of this condition
c. Predisposing factors include old age, malnutrition, and immunosuppression
d. Pseudomonas bacteremia is the most common cause of gram-negative sepsis.
Answer: c
Gram-negative bacterial sepsis is a serious disease process that produces substantial morbidity and mortality in both normal and immunocompromised patients (10% to 20% and 30% lethality, respectively), despite therapeutic intervention with antimicrobial agents, aggressive hemodynamic monitoring, fluid resuscitation, and metabolic support. During the past several decades, nosocomial infections due to gram-negative pathogens have increased in frequency with resultant increase in the incidence of gram-negative bacteremia to between 3 and 13 cases per 1000 hospital admissions. Factors that predispose to these infections include: 1) underlying host disease processes such as malignancy, diabetes; 2) old age and disability; 3) malnutrition; 4) previous or concurrent antimicrobial antibiotic therapy; 5) major operations; 6) respiratory or urinary manipulation or intubation; and 7) immunosuppression.
Although many different organisms cause this form of sepsis, E. coli predominates in overall frequency. Also common are isolates of Klebsiella, Enterobacter and Serratia; Pseudomonas bacteremia is less common. Some studies, however, have suggested that Pseudomonas sepsis is associated with the highest lethality. In several series, 10% to 20% of patients have had polymicrobial series, and most investigators agree that polymicrobial sepsis is more lethal than infection with a single organism.
-----------------------------------------------------------------------------------------------------------------
11. the initial treatment in patient with a serum potassium of 6.5 with ECG changes is:
a- calcium gluconate( bicarbonate) I.V
b- kayexalate enema
c- kayexalate enema & given orally
d- haemodialysis
answer A
treatment of symptomatic hyperkalemia :
= counteract cardiac effect (calcium gluconate 5-10 ml of 10% solution )
=shift K inside the cells( glucose 1 ampoule of D50 and regular insulin 5-10 units iv)
Or ( bicarbonate 1 ampoule iv)
=K removal (dialysis)
Or (kayexalate oral 15-30 gm in 50 -100 ml of 20% sorbitol ,, or rectal is 50 gm in 200 ml of 20% sorbitol).
--------------------------------------------------------------------------------------------------------------
12.metabolic acidosis with a normal anion gap occurs with:
a-diabetic acidosis
b-renal failure
c-severe diarrhea
d-starvation
answer C
Normal anion gap= 8-12 = Na – (cl +Hco3)
Metabolic acidosis with normal anion gap results from either acid administration or a loss of bicarbonate from GIT (diarrhea , fistulas ) , uretrosigmoidostomy or from renal loss ,, the bicarbonate loss is accompanied by a gain of chloride , then the anion gap unchanged.
So causes of normal anion gap(high chloride) are:
Renal tubular acidosis , diarrhea , billiary or pancreatic fluid losses , sulfamylon , smaal bowel fistula , dilutional acidosis , acetazolamide , and uretral diversion.
High anion gap:
=Endogenous acid production ( Renal failure(organic acids
( ketoacidosis ( B-hydroxybutyrate and acetoacetate )
( lactic acidosis ( lactate)
=Exogenous acid ingestion( alcohol intoxication ,methanol, ethylene glycol , ethanol , salicylates , and paraldehyde.)
-----------------------------------------------------------------------------------------------------------------
13 . which of the following is an early sign of hyperkalemia:
a-peaked T waves
b-peaked P waves
c-peaked (shortened) QRS complex
d-peaked U waves
answer A
Symptoms of hyperkalemia are primarily GIT , Neuromuscular , and CVS
GIT ( N\V , intestinal colic , and diarrhea.
Neuromuscular ( range from weakness to ascending paralysis to respiratory failure.
CVS ( range from ECG changes to cardiac arrhythmias to arrest .
( ECG changes that may be seen :
-peaked T waves (early change)
-flattened P wave
-prolonged P-R interval (1st degree block)
-widened QRS
-sine wave formation
-ventricular fibrillation.
-----------------------------------------------------------------------------------------------------------------
14 . the next most appropriate test to order in a patient with :
pH 7.1
Pco2 40
Na 132
K 4.2
Cl 105 is:
a-serum magnesium
b-serum bicarbonate
c-serum ethanol
d-serum salicylate
answer B
Metabolic acidosis
Normal anion gap= 8-12 = Na – (cl +Hco3)
Metabolic acidosis with normal anion gap results from either acid administration or a loss of bicarbonate from GIT (diarrhea , fistulas ) , uretrosigmoidostomy or from renal loss ,, the bicarbonate loss is accompanied by a gain of chloride , then the anion gap unchanged.
So causes of normal anion gap(high chloride) are:
Renal tubular acidosis , diarrhea , billiary or pancreatic fluid losses , sulfamylon , smaal bowel fistula , dilutional acidosis , acetazolamide , and uretral diversion.
High anion gap:
=Endogenous acid production ( Renal failure(organic acids
( ketoacidosis ( B-hydroxybutyrate and acetoacetate )
( lactic acidosis ( lactate)
=Exogenous acid ingestion( alcohol intoxication ,methanol, ethylene glycol , ethanol , salicylates , and paraldehyde.)
15 . a serum Na of 129 seen in the immediate post op :
a-warrants aggressive treatment with hypertonic saline to prevent seizures
b-should be treated with boluses of normal saline until corrected
c-is a self limiting problem due to transient increase in ADH secretion.
d-is due to excessive fluids given intraoperatively
answer C
Hyponatremia occurs when there is an increase in ECF water relative to Na .
ECF volume can be high , normal or low.
For most cases of hypo Na , sodium conc. Is decreased as a consequences of either Na depletion or dilution .
Dilutional hyponatremia :
Frequently results from excess extracellular volume status , either intentional (excessive oral water intake ) or iatrogenic (i.v )overload of free water.
Post op patient are particularly prone to increased secretion of ADH , which increase reabsorbtion of free water from kidneys with a subsequent volume expansion and dilutional hyponatremia.
Usually self limiting with feedback on ADH (decrease ADH then come to normal.
Depletional hyponatremia:
Decrease intake of Na or increase loss .
Decrease intake ( low sodium diet , or enteral feeds low in Na.
Increase loss ( GIT loss (vomiting , prolonged NGT suctioning , or diarrhea)
( renal loss (diuretics , primary renal disease)
16.a patient who has spasms in the hand when a blood pressure cuff is blown up most likely has:
a-hypercalcemia
b-hypocalcemia
c-hypermagnesemia
d-hypomagnesemia
answer B
Asymptomatic hypocalcemia ,may occur with low albumin (normal ionized Ca)
Corrected Ca =(3.5 –Pt albumin ) ×0.8 +Pt Ca
In general , symptoms do not occur until the ionized fraction decrease below 2.5 mg/dl
,and will be neuromuscular or cardiac.
(parasthesia of the face and extremities (circumoral parasthesia )
(ms cramps .
(carpopedal spasm
( stridor
(tetany , and seizures .
← hyper-reflexia and positive Chvostek s sign (spasm result from tapping over the facial nerve , over masseter ms)
← and Trousseau s sign (spasm resulting from pressure applied to the nerves and vessels of the upper arm ,,, inflate pressure cuff above systolic pressure for 3 mints.
← Decrease cardiac contractility
← Can lead to heart failure .
← ECG =prolonged QT interval
Etiology :
Check albumin , and alkalosis (can lead to hypocalcemia)
If albumin is normal ( check PTH if low (hypoparathyroidism ) or Mg deficiency .
If high PTH ( look for – pancreatitis , hyperphosphatemia ,vitD toxicosis , massive citrated blood transfusions , drugs like gentamicin and frusemide , renal insufficiency ,small bowel fistula and massive soft tissue infection.
Treatment:
Acute ( iv CaCl or Ca gluconate ( 10 ml as 10 % solution)
Chronic ( oral Ca carbonate , and phosphate – binding antacids …..improve GIT absorption
( Vit D orally ….. begin once phosphate is normal
(50000 units /day and increase up to 200000 as needed)
17 .metabolic acidosis with a normal anion gap is found in a patient with:
a- alcohol intoxication
b-aspirin ingestion
c-diabetic ketoacidosis
d- small bowel fistula
answer D
A normal anion gap occur in an acidotic patient who is not producing abnormal acid
Increase ketoacids are found in alcoholics and diabetics with ketoacidosis.
Aspirin ingestion ( abnormal amounts of sulfuric acid.
-----------------------------------------------------------------------------------------------------------------
18 . the effective osmotic pressure between the plasma and interstitial fluid compartments is primarily controlled by:
a-bicarbonate
b-chloride
c-potassium
d-protein
answer D
The dissolved protein in plasma does not pass through the semi permeable cell membrane , and this fact is responsible for the effective or colloid osmotic pressure.
----------------------------------------------------------------------------------------------------------------
19 .which of the following best describes the composition of gastric secretions?
a-Na 60 Cl 60
b-Na 60 Cl 110
c- Na 110 Cl 60
d- Na 110 Cl 110
answer B
volume Na K Cl Hco3
Salivary 500-2000 10 26 10 30
Stomach 1000-2000 60-90 10-30 100-130 0
Small bowel 2000-3000 120-140 5-10 90-120 30-40
Colon --------- 60 30 40 0
Pancreas 600-800 135-145 5-10 70-90 95-115
Bile 300-800 135-145 5-10 90-110 30-40
-----------------------------------------------------------------------------------------------------------------
20 . the highest concentration of potassium found in:
a-small intestine
b-colon
c- bile
d-pancreatic secretions
e-blood
answer B
-----------------------------------------------------------------------------------------------------------------
21 . the highest concentration of bicarbonate is found in:
a-small intestine
b-colon
c- bile
d-pancreatic secretions
e-blood
answer D
-----------------------------------------------------------------------------------------------------------------
22 .acute severe postoperative hyponatremia is most common :
a-in patients with congestive heart failure
b-as a complication of acute renal failure
c- in a woman with small stature
d- in a man with small stature
answer C
Reported by studies that menstruating women with hyponatremia had more symptoms than men with equivalent suppressions in serum sodium concentrations ,
And surgeons can reduce the risk of postoperative hyponatremia by always ordering isotonic IVF.
Further more patients particularly small-statured women who develop lethargy ,headache , and altered mental status in postoperative period should have serum Na checked.
-----------------------------------------------------------------------------------------------------------------
23 .55 y/o post abdominal surgery 5th day , his laps was:
pH 7.56 , Po2 85 , Pco2 50
Na 132 ,K 3.1 , Cl 80 , HCO3 42 ,
Urine analysis Na 2 , K 5 , Cl 6
The values given above is diagnosis of:
a-uncompensated metabolic alkalosis
b-respiratory acidosis with metabolic compensation
c-combined metabolic and respiratory alkalosis
d-metabolic alkalosis with respiratory compensation
e-paradoxical metabolic respiratory alkalosis
answer D
both the arterial PH and the Pco2 are elevated in this patient ,,,, the disturbance is alkalosis with hypoventilation .
The Pco2 typically increases by 0.5 to 1.0 PKa for each Meq /L increase in serum bicarbonate .
These findings suggest that the hypoventilation is compensatory rather than , a primary phenomenon.
24.Generally, the two most important hepatic functions to consider after hepatic resection are:
A. Hepatic synthetic function(protein synthesis) ,and glucose metabolism .
B. Glucose metabolism and lipid metabolism .
C. The liver's role in lipid metabolism and Hepatic synthetic function(protein synthesis).
D. Hepatic synthetic function(protein synthesis) and liver's role in vitamin metabolism.
Answer: A
While other functions undoubtedly may be important postoperatively, the most common abnormalities occurring after a major hepatic resection are related to loss of protein synthesis and consequences of glucose metabolism. Therefore, it is usually advisable to administer supplemental amounts of protein and sugar postoperatively.
25.Which of the following statements about choledocholithiasis is false?
A. Common duct stones can originate in the gallbladder and migrate to the common duct, and stones can form de novo in the duct system.
B. Calcium bilirubinate stones are associated with the presence of bacteria in the duct system.
C. Common duct stones discovered at laparoscopic cholecystectomy can be treated by postoperative endoscopic extraction.
D. The serum bilirubin value is usually greater than 15 mg. per dl. in the patient with a symptomatic common duct stone.
Answer: D
Most common duct stones originate in the gallbladder and migrate to the common duct, where they may become larger. These stones tend to consist predominantly of cholesterol (about 80% of gallbladder stones are predominantly cholesterol). Stones found in the bile ducts after cholecystectomy may have been overlooked, but de novo stone formation does occur. Arbitrarily, stones found 2 years after cholecystectomy are assumed to have formed within the duct system. Calcium bilirubinate stones are thought to result from precipitation of insoluble bilirubin monoglucuronide formed by deconjugation of bilirubin diglucuronide, a reaction promoted by the enzyme beta-glucuronidase, which is produced by bacteria in the biliary tract. Calcium bilirubinate stones are found almost exclusively in patients who have some form of biliary tract lesion that causes partial obstruction, and these patients tend to have bactibilia. Stones smaller than approximately 5 mm. often can be extracted through a dilated cystic duct or pushed into the duodenum. Larger stones are best left for postoperative endoscopic sphincterotomy and extraction. Patients with more than five stones or stones larger than 1.5 cm. should be treated by open choledocholithotomy or, when indicated, a biliary-enteric anastomosis. Not all patients with symptomatic common duct stones have elevated serum bilirubin, but when jaundice is present the bilirubin is only rarely greater than 15 mg. per dl.
26.Which of the following explanations accounts for the fact that hepatitis C is the most common cause of posttransfusion hepatitis?
A. There are more carriers of hepatitis C virus (HCV) in the normal population who serve as blood donors.
B. Blood infected with hepatitis B virus (HBV) is eliminated through routine testing, leaving only HCV as the other blood-borne pathogen.
C. Questions designed to eliminate risk groups for HCV from the normal donor population may are as specific as would be desirable.
D. Hepatitis C is a more virulent form of viral hepatitis, so it is expected that more cases of posttransfusion hepatitis would occur.
Answer: B
The ability to specifically identify persons infected with HCV has only recently become available. Therefore, data about epidemiology are less than complete. It is very likely not true that more blood donors carry HCV because of the large preponderance of HBV in the United States. It is true, however, that successful elimination of most of the HBV carriers occurs through routine testing. Although serologic tests are available for HCV, they are tests, not of antigen, but of antibody. Therefore, this test alone may not screen out persons who are infected but have not yet developed or may never develop antibody. Risk groups for the relatively newly defined HCV may well not be comprehensively established, and therefore this explanation may be a contributor. There are no differences in virulence between these classes of hepatitis virus.
27.Which of the following statements about biliary tract problems are correct?
A. Choledochal cysts should be treated by Roux-en-Y cystojejunostomy.
B. Sclerosing cholangitis is characterized by long, narrow strictures in the extrahepatic biliary duct system.
C. Fusiform Choledochal cyst should be treated by excision of the cyst with biliary reconstruction by Roux-en-Y hepaticojejunostomy.
D. The long cystic duct, which appears to be fused with the common duct and enters it distally, should be dissected free and ligated at its entrance into the common duct.
Answer: C
In the past, choledochal cyst was treated by Roux-en-Y cystojejunostomy, but long-term results were poor. Excision of the cyst is essential to prevent recurrent pancreatitis. In addition, the development of carcinoma in about 25% of patients mandates cyst excision. Accordingly, excision of the cyst with biliary reconstruction by Roux-en-Y hepaticojejunostomy and diversion of the flow of pancreatic juice through the ampulla of Vater is currently the standard treatment.
Sclerosing cholangitis causes fibrosis of bile ducts both within and outside the liver. This process, which is poorly understood, causes strictures in the duct system, characteristically with normal or dilated segments between strictures. Unfortunately, this anatomic arrangement does not lend itself to biliary reconstructive procedures. Each case must be analyzed, however, because in some patients the anatomic situation may lend itself to balloon dilatation or reconstruction. Dissection of a long, fused cystic duct is fraught with hazard because the cystic and common ducts may share a common wall and serious duct damage may occur. The cystic duct should be ligated and divided immediately proximal to the area of fusion.
-----------------------------------------------------------------------------------------------------------------
28.Which of the following statements about cholangitis IS correct?
A. Charcot's triad (pain, chills and fever, jaundice) is diagnostic of cholangitis, the complete triad occurs only in 50% to 70% of patients.
B. A clear associated biliary tract disease is always present.
C. Chills and fever are due to the presence of bacteria in the bile duct system.
D. The most common cause of cholangitis is benign and malignant strictures.
Answer: A
Although Charcot's triad (pain, chills and fever, jaundice) is diagnostic of cholangitis, the complete triad occurs only in 50% to 70% of patients. Fever is the most common symptom; therefore, cholangitis should be considered in all patients who have unexplained fever. Episodes of pain, chills, and fever are often so brief as not to concern the patient. Cholangitis does not occur in the absence of partial or complete bile duct obstruction. All patients diagnosed as having cholangitis should have appropriate diagnostic studies to determine the cause. This usually involves cholangiography.
The presence of bacteria in bile does not produce symptoms in the absence of partial or complete obstruction of the bile duct system. When obstruction is present, pressure within the system increases, giving rise to reflux of bacteria or their toxic products into the hepatic venous circulation. This cholangiovenous reflux produces chills, fever, and the hemodynamic changes of sepsis. Death may ensue if treatment is not instituted promptly.
Choledocholithiasis, the most commonly associated problem, may produce partial or complete obstruction. When bacteria are not present in the bile duct system, choledocholithiasis may go undetected unless the degree of obstruction is sufficient to cause jaundice. Other causes of cholangitis are benign and malignant strictures, biliary-enteric anastomoses, invasive procedures, foreign bodies, and parasitic infestation of the bile ducts.
29.The clinical picture of gallstone ileus includes ALL of the following EXCEPT?
A. Air in the biliary tree.
B. Small bowel obstruction.
C. A stone at the site of obstruction.
D. Acholic stools.
E. Associated bouts of cholangitis.
Answer: D
An antecedent biliary-enteric fistula is necessary to allow stone migration into the intestinal tract, and this results in air entering the biliary tree (pneumobilia). It also allows contamination of the bile ducts with intestinal bacteria, which in fact occurs in only a minority of such cases. The stone obstructs the narrower distal bowel, producing small bowel obstruction. Such a stone, if opaque, can be seen on plain radiography and, if not, can be appreciated by sonography. Stools are not acholic, since the cholecystoenteric fistula allows bile access to the intestinal lumen.
-----------------------------------------------------------------------------------------------------------------
30.Which of the following statements about gallstone ileus is not true?
A. The condition is seen most frequently in women older than 70.
B. Concomitant with the bowel obstruction, air is seen in the biliary tree.
C. The usual fistula underlying the problem is between the gallbladder and the ileum.
D. When possible, relief of small bowel obstruction should be accompanied by definitive repair of the fistula since there is a significant incidence of recurrence if the fistula is left in place.
E. Ultrasound studies may be of help in identifying a gallstone as the obstructing agent.
Answer: C
It is true that gallstone ileus occurs mostly in elderly women and should always be suspect when small bowel obstruction presents in this age group. The great majority of cases of gallstone ileus are preceded by a spontaneous fistula occurring between the gallbladder and duodenum, allowing gallstones to enter the intestinal tract, which can potentially block the terminal ileum. Finding air within the biliary tree should always arouse suspicion of the possibility of this diagnosis when it is associated with a radiographic pattern of small bowel obstruction. The initial part of the operative approach to this disease is to relieve the bowel obstruction by performing an enterotomy just proximal to the point of obstruction to remove the stone. Where possible, definitive repair of the fistula should be undertaken to avoid recurrent obstruction and to obviate the possible recurring complications of cholangitis. Percutaneous drainage of bile collections combined with endoscopic papillotomy may be sufficient treatment for external and internal biliary fistulas but is never an allowable approach in the presence of gallstone ileus with small bowel obstruction. Relief of the obstruction is mandated in this setting.
-----------------------------------------------------------------------------------------------------------------
31.Which of the following lesions are believed to be associated with the development of carcinoma of the gallbladder?
A. Cholecystoenteric fistula.
B. A calcified gallbladder.
C. Adenoma of the gallbladder.
D. Xanthogranulomatous cholecystitis.
E. All of the above.
F. None of the above.
Answer: E
The prevalence of carcinoma of the gallbladder in patients who have or have had a cholecystoenteric fistula is believed to be 15%. The prevalence of carcinoma in a calcified, or “porcelain,” gallbladder is reported to range from 12.5% to 61%. It is generally accepted that adenoma of the gallbladder is a precancerous lesion that presents as a polypoid lesion. Xanthogranulomatous cholecystitis is a rare form of chronic cholecystitis believed to be associated with a higher incidence of cancer. This form of cholecystitis is also important because, grossly, it may mimic cancer of the gallbladder.
32. Which of the following statements about pancreatic embryonic malformations is false?
A. Pancreas divisum is a known cause of gastrointestinal bleeding.
B. Heterotopic pancreatic tissue predisposes to intestinal obstruction, ulceration, or hemorrhage.
C. Annular pancreas may cause gastrointestinal obstruction in children or in adults.
D. Relative obstruction to the flow of pancreatic juice through the minor papilla appears to be the cause of pancreatitis in some patients with pancreas divisum.
Answer: a
The clinically recognized embryonic malformations of the pancreas include heterotopic pancreas, pancreas divisum, and annular pancreas. Heterotopic pancreatic tissue most often takes the form of a firm nodule of variable size in the stomach, duodenum, small bowel, or Meckel's diverticulum. The typical complications of heterotopic pancreas include intestinal obstruction, ulceration, or hemorrhage. Pancreas divisum is an anatomic variant that results from failure of fusion of the two primordial pancreatic duct systems. In pancreas divisum the major portion of the pancreas is drained via the duct of Santorini through the minor duodenal papilla. Relative stenosis of the minor duodenal papilla can cause pancreatitis. Pancreas divisum is not associated with gastrointestinal bleeding. Annular pancreas results when histologically normal pancreatic tissue completely or partially encircles the second portion of the duodenum. Varying degrees of duodenal obstructive symptoms may be observed in both children and adults with this condition.
-----------------------------------------------------------------------------------------------------------------
33. The pancreas occupies a retroperitoneal position in the upper abdomen. Which statements is false?
A. The superior mesenteric vein and the splenic vein join to form the portal vein posterior to the neck of the pancreas.
B. The uncinate process of the pancreas extends posterior to the inferior vena cava.
C. The tail of the pancreas extends to the left of the aorta, toward the splenic hilum.
D. The head of the pancreas is jointly supplied by arterial blood from the celiac axis and the superior mesenteric artery.
Answer: b
The pancreas occupies a retroperitoneal position in the upper abdomen, extending obliquely from the duodenal C loop to a more cephalad position where the pancreatic tail abuts the hilum of the spleen. The portion of the pancreas anterior to the confluence of the superior mesenteric vein, splenic vein, and portal vein is designated the neck of the gland. The uncinate process extends posterior to the superior mesenteric vein and approaches the superior mesenteric artery. The head of the pancreas is intimately associated with the second portion of the duodenum, and these two structures are jointly supplied by two arterial arcades known as the anterior and posterior pancreaticoduodenal arteries, which originate as branches of the celiac axis and superior mesenteric artery.
-----------------------------------------------------------------------------------------------------------------
34. Both endocrine and exocrine tissue comprise the pancreas. Which statement(s) is true?
A. The islets of Langerhans total 1 million per gland and drain their secretions via intercalated duct cells through the ampulla of Vater.
B. Islet alpha cells produce insulin .
C. Islet beta cells produce somatostatin.
D. The acini and ductal systems constitute the exocrine portion of the pancreas.
Answer: D
The endocrine portion of the pancreas is served by the islets of Langerhans, which number 1 million islets per gland. The islets of Langerhans drain their endocrine secretions into the bloodstream. Insulin-producing beta cells comprise the majority of the islet population. Alpha cells produce glucagon and constitute approximately 20% to 25% of the total islet cell number. Delta cells of the islets produce somatostatin. The acini and ductal systems constitute the exocrine portion of the pancreas. The acinar cells contain zymogen granules in their narrow, centrally located apical portion. The pancreatic duct system includes intercalated duct cells along the ductal pathway, terminating in the main excretory duct of the pancreas.
-----------------------------------------------------------------------------------------------------------------
35. Pancreatic exocrine secretory products include a bicarbonate-rich electrolyte solution as well as digestive enzymes. Which of the following statement(s) is FALSE?
A. Cholecystokinin (CCK) is the most potent endogenous stimulant of pancreatic enzyme secretion.
B. The chloride and bicarbonate concentrations of pancreatic juice vary and depend on the secretory flow rate.
C. Secretin is the most potent endogenous stimulant of pancreatic water and electrolyte secretion.
D. The peptidases synthesized by acinar cells are released into the pancreatic duct system in active form.
Answer: D
CCK is the most potent endogenous stimulant of pancreatic enzyme secretion. The pancreatic acinar cells respond to CCK with release of their zymogen granules into the ductal system. Peptidases are released in inactive form, later to be activated by contact with duodenal enterokinase and activated trypsin. Secretin is the most potent endogenous stimulant of pancreatic water and electrolyte secretion. The concentrations of the anions bicarbonate and chloride vary and are largely dependent on the secretory flow rate stimulated by secretin.
-----------------------------------------------------------------------------------------------------------------
36. Which of the following parameters is not included in the Ranson's prognostic signs useful in the early evaluation of a patient with acute pancreatitis?
A. Elevated blood glucose.
B. Leukocytosis.
C. Amylase value greater than 1000 U per dl.
D. Serum lactic dehydrogenase (LDH) greater than 350 IU per dl.
Answer: C
Several prognostic systems have been demonstrated to predict the severity of pancreatitis accurately. Two Ranson prognostic criteria have been developed: one each, for pancreatitis that is not due to gallstones and pancreatitis that is. The systems have minor differences. In both of the Ranson systems elevated blood glucose, leukocytosis, and elevations of serum LDH have proved to have prognostic importance. The degree of amylase elevation is not one of the parameters, nor is the degree of ALT elevation.
Ranson prognostic signs include:
ON ADMISSION
Age above 55 years
White blood cell count above 16,000/µL
Glucose level above 200 mg/dL
Lactase dehydrogenate level above 350 IU/L
SGOT value above 250 IU/L
AFTER 48 HOURS
Hematocrit decrease of 10%
Blood urea nitrogen level increase of 5 mg/dL
Ca2+ level below 8 mg/dL
PaO2 level below 60 mmHg
Base deficit value above 4 mEq/L
Fluid sequestration greater than 6 L
----------------------------------------------------------------------------------------------------------
37. Standard supportive measures for patients with mild pancreatitis include WHICH OF the following:
A. Intravenous fluid and electrolyte therapy.
B. Withholding of analgesics to allow serial abdominal examinations.
C. Subcutaneous octreotide therapy.
D. Nasogastric decompression.
E. Prophylactic antibiotics.
Answer: A
Standard therapy for all patients with mild acute pancreatitis should include intravenous fluid resuscitation, electrolyte replacement, and analgesics. Nasogastric decompression is typically reserved for patients with significant ileus who are at risk for emesis and aspiration. Subcutaneous therapy with octreotide, the octapeptide analog of somatostatin, has not been proven to influence the outcome in patients with mild pancreatitis. Prophylactic antibiotics are not used for mild pancreatitis. Antibiotics are reserved for patients with severe pancreatitis (defined as greater than three Ranson prognostic signs with associated CT evidence of pancreatic or peripancreatic necrosis).
-----------------------------------------------------------------------------------------------------------------38. Which of the following statements about chronic pancreatitis is correct?
A. Chronic pancreatitis is the inevitable result after repeated episodes of acute pancreatitis.
B. Patients with chronic pancreatitis commonly present with jaundice, pruritus, and fever.
C. Mesenteric angiography is useful in the evaluation of many patients with chronic pancreatitis.
D. Total pancreatectomy offers the best outcome in patients with chronic pancreatitis.
E. For patients with disabling chronic pancreatitis and a dilated pancreatic duct with associated stricture formation, a longitudinal pancreaticojejunostomy (Peustow procedure) is an appropriate surgical option.
Answer: E
Chronic pancreatitis is a clinical entity that includes recurrent or persistent abdominal pain with evidence of exocrine and endocrine pancreatic insufficiency. While chronic pancreatitis may result from repeated episodes of acute pancreatitis, not all patients with recurring acute pancreatitis progress to chronic pancreatitis. The most common causes of chronic pancreatitis include alcohol abuse, hyperparathyroidism, congenital anomalies of the pancreatic duct, pancreatic trauma, and cystic fibrosis. The most useful radiographic tests in patients with suspected chronic pancreatitis are CT and endoscopic retrograde cholangiopancreatography (ERCP). Mesenteric angiography has no role in the evaluation of most patients with chronic pancreatitis. Patients with disabling chronic pancreatitis who require operative intervention are candidates for a longitudinal pancreaticojejunostomy (Peustow procedure) if pancreatography demonstrates a dilated pancreatic duct. Total pancreatectomy is rarely performed because of the significant problems associated with labile insulin sensitivity, steatorrhea, and weight loss.
-----------------------------------------------------------------------------------------------------------------
39. Which of the following statements about pancreatic ascites is correct?
A. Patients typically present with painful ascites, reflecting the release of toxic pancreatic enzymes into the peritoneal cavity.
B. The standard evaluation of a patient with new-onset ascites includes abdominal paracentesis. In cases of pancreatic ascites, the peritoneal fluid contains high concentrations of both amylase and protein.
C. Pancreatic ascites is frequently all episodes of acute pancreatitis.
D. Patients with pancreatic ascites may fail to improve with nonoperative therapy and require surgical procedures. At abdominal exploration an acceptable approach to the pancreatic duct disruption involves suture ligation with omental patching.
Answer: B
Pancreatic ascites typically occurs because of a pancreatic duct disruption, most commonly involving alcohol abuse and resultant acute pancreatitis. In pancreatic ascites, pancreatic exocrine secretions exit a pancreatic duct disruption and drain anteriorly into the peritoneal cavity. Patients typically present with painless massive ascites, as the pancreatic enzymes that extravasate into the peritoneal cavity are typically nonactivated. The diagnosis of pancreatic ascites is best made by paracentesis, in which the analysis of the ascites fluid reveals it to be high in amylase (more than 1000 U. per dl.) and high in albumin (more than 3 gm. per dl.). Nonoperative treatment is initially indicated in most patients with pancreatic ascites. Should nonoperative therapy fail, surgical therapy is directed to closure of the pancreatic duct disruption. Preoperative pancreatography is useful in directing surgical therapy. Distal pancreatic duct disruption may be treated with distal pancreatectomy or with Roux-en-Y pancreaticojejunostomy. Pancreatic leaks in the more proximal aspects of the gland are treated with Roux-en-Y pancreaticojejunostomy. Suture ligation of the pancreatic duct with omental patching is not considered appropriate therapy for pancreatic duct disruptions.
40. Which of the following statements about gastrinoma (Zollinger-Ellison syndrome) is not correct?
A. As many as 25% of gastrinoma patients have sporadic disease; 75% have gastrinoma associated with multiple endocrine neoplasia type 1 (MEN 1).
B. Extrapancreatic gastrinomas are common, and exploration should include careful assessment of the duodenum and peripancreatic lymph nodes.
C. Diarrhea may be a prominent presenting feature of some patients with gastrinoma.
D. Before elective operation acid-reducing medications such as omeprazole should be administered.
Answer: A
Gastrinoma patients typically present with peptic ulceration of the upper gastrointestinal tract and abdominal pain. As many as 50% of patients may have diarrhea, which may be a prominent feature in some cases. Approximately 25% of gastrinoma patients have the disease associated with the MEN-1 syndrome, whereas 75% have a sporadic variety of the disease. Recent evidence indicates that extrapancreatic gastrinomas are common. Careful attention must be paid to the duodenum and peripancreatic lymph nodes at the time of abdominal exploration. Before elective operation it is imperative that the gastric acid hypersecretion be controlled. The control of gastric hypersecretion is best performed by the administration of one of the substituted benzimidazoles, such as omeprazole or lansoprazole.
-----------------------------------------------------------------------------------------------------------------
41.In the performance of a pancreaticoduodenectomy (Whipple procedure), the superior mesenteric vein is an important landmark. Which of the following statements is true with regard to the superior mesenteric vein?
A.Small venous branches enter the superior mesenteric vein anteriorly as it courses beneath the neck of the pancreas
B.The superior mesenteric vein joins the splenic vein at the superior border of the pancreas behind the head to form the portal vein.
C.Small venous branches enter the superior mesenteric vein laterally as it courses beneath the neck of the pancreas
D.The superior mesenteric vein courses anterior to the neck of the pancreas
Answer: c
The venous drainage of the pancreas and duodenum follows the arterial supply. The anterior and posterior venous arcades drain the head; the body and tail drain into the splenic vein. All venous effluent from the pancreas ultimately drains into the portal vein which is formed by the confluence of the superior mesenteric vein and the splenic vein at the superior border of the pancreas. The anterior and posterior venous arcades in the head of the pancreas drain directly into the suprapancreatic portal vein. The anteroinferior pancreaticoduodenal arcades drain with the right gastroepiploic vein to form a common venous trunk with the right colic vein. This trunk is known as the gastrocolic trunk and enters the superior mesenteric vein at the inferior border of the neck of the pancreas. The posteroinferior venous arcade empties directly into the superior mesenteric vein. The veins of the head drain laterally into the superior mesenteric and portal veins. There are no venous tributaries entering the superior mesenteric vein anteriorly. For this reason, it is safe to dissect the neck of the pancreas directly anterior to the superior mesenteric and portal veins when performing a pancreaticoduodenectomy.
-----------------------------------------------------------------------------------------------------------------
42.Pancreas divisum results from incomplete fusion of the ventral pancreatic duct with the dorsal pancreatic duct during embryologic development. Which of the following statements correctly describes pancreas divisum?
A.The body and tail of the pancreas drain via an accessory ampulla distal to the ampulla of Vater. The uncinate process drains via the ampulla of Vater
B.The entire pancreatic ductal system drains via the ampulla of Vater.
C.The most of pancreatic ductal system drains via an accessory ampulla proximal to the ampulla of Vater
D.The body and tail of the pancreas are absent. The uncinate process drains via the ampulla of Vater
Answer: C
In 90% of individuals, the main pancreatic duct, or duct of Wirsung, runs the entire length of the pancreas and joins the common bile duct to empty into the duodenum at the ampulla of Vater. The pancreatic duct is 2 to 3.5 mm in diameter and contains 20 secondary branches, which drain the tail, body, and uncinate process. The drainage of the lesser duct, or duct of Santorini, is variable. The lesser duct commonly drains the superior portion of the head of the pancreas. It empties separately into the second portion of the duodenum through the lesser papilla located 2 cm proximal to the ampulla of Vater. Pancreas divisum results from an incomplete fusion of the ventral pancreatic duct with the dorsal duct during fetal development and is present in 5% of patients. In this anomaly, the lesser duct drains the entire pancreas via an accessory ampulla located proximal to the ampulla of Vater. Inadequacy of this pattern of drainage can result in chronic pain.
-----------------------------------------------------------------------------------------------------------------
43.Which of the following statements is correct with regard to the blood supply of the pancreas?
A.The inferior pancreaticoduodenal artery, a branch of the celiac artery, divides into anterior and posterior branches to supply the pancreatic head
B.The body and tail of the pancreas are supplied by branches of the inferior mesenteric artery.
C.The superior pancreaticoduodenal artery is a branch of the gastroduodenal artery
D.The body and tail of the pancreas are supplied by branches derived from the left renal artery
Answer: c
The pancreas receives its blood supply from a variety of major arterial sources. In the head of the pancreas, there are arcades in the anterior and posterior surfaces, which generally collateralize. These arcades arise from branches of the gastroduodenal and the superior mesenteric arteries. Just distal to the first portion of the duodenum, the gastroduodenal artery becomes the superior pancreaticoduodenal artery, which divides into anterior and posterior branches. The inferior pancreaticoduodenal artery is the first branch of the superior mesenteric artery and divides into anterior and posterior branches.
The body and tail of the pancreas are supplied by the splenic artery. The splenic artery arises from the celiac trunk and courses along the superior surface of the pancreas to the spleen. Approximately ten branches of the splenic artery supply the body and tail of the pancreas.
44.A 42-year-old male develops acute pancreatitis in the setting of acute alcohol abuse. One week after onset of symptoms, computed tomography of the abdomen reveals a pancreatic phlegmon and associated pseudocyst. Which of the following factors, if present, will not decrease the likelihood of spontaneous resolution of the pseudocyst?
A.Size greater than 5 cm
B.Diffuse calcification of the pancreatic gland
C.Multilocularity
D.Location in the pancreatic tail
Answer: D
Initial management of pancreatic pseudocysts is based on symptoms. If the patient is asymptomatic and the cyst is small (< 5.0 cm) it can be safely observed as many of these will resolve over a period of weeks. Concurrent chronic alcoholic pancreatitis (by history or as indicated by pancreatic calcification), pseudocyst size greater than 5 cm, the presence of a multilocular or debris-filled pseudocyst cavity, and chronicity (longer than 6 weeks) are all factors that are associated with a lower probability of spontaneous resolution.
-----------------------------------------------------------------------------------------------------------------
45.A 36-year-old woman is admitted to a the hospital with upper abdominal pain, hyperamylasemia, elevation of serum alkaline phosphatase and ultrasound evidence of cholelithiasis. With intravenous hydration and analgesia, symptoms rapidly resolved. After 48 hours, serum amylase and alkaline phosphatase values had returned to normal and physical examination revealed lessening tenderness in the right upper quadrant of the abdomen. Appropriate management consists of which of the following as the next step?
A.Cholecystectomy before hospital discharge.
B.Elective cholecystectomy at approximately 8 weeks
C.Endoscopic sphincterotomy before discharge followed by cholecystectomy at approximately 8 weeks
D.Observation
Answer: a
A patient who has simple cholelithiasis and an episode of acute pancreatitis is usually treated nonoperatively until clinical resolution of the pancreatitis occurs. The rate of recurrent biliary pancreatitis is as high as 34% to 56% within 6 weeks; therefore, an
aggressive operative approach is appropriate. Cholecystectomy is often performed after the resolution of acute pancreatitis but before hospital discharge. Common bile duct instrumentation in this setting has a substantially increased risk of recurrent acute pancreatitis
46.The most appropriate test to confirm a clinical diagnosis of early chronic pancreatitis is which of the following?
A.Serum amylase determination
B.Calculation of urinary amylase clearance
C.Measurement of para-aminobenzoic acid absorption
D.Endoscopic retrograde cholangiopancreatography
Answer: d
Routine tests of blood or serum are not helpful in making a diagnosis of chronic pancreatitis. Although serum amylase levels are almost always elevated in acute pancreatitis—amylase levels may be normal, elevated, or subnormal in chronic pancreatitis. Determination of urinary amylase secretion and calculation of urinary amylase clearance does not improve sensitivity or specificity. Indirect tests of pancreatic function which measure absorption of nutrients that first require pancreatic digestion are not helpful in early cases of chronic pancreatitis. Clinically detectable malabsorption is absent until 90% of exocrine function is lost. Because of this, indirect tests of pancreatic function do not detect early disease. In addition, false positive tests may occur in other disease states associated with malabsorption (Crohn’s disease, sprue, postgastrectomy states, or in association with diabetes mellitus, cirrhosis, or renal disease. ERCP has become widely recognized as the most sensitive and reliable method for diagnosing chronic pancreatitis. Sensitivity approaches 90% with equal specificity.
----------------------------------------------------------------------------------------------------------------
47.A 72-year-old man develops jaundice and is demonstrated to have a 2.5 mass in the pancreatic head by computed tomography. There are no signs of unresectability on CT examination. Fine needle aspiration cytology is positive for adenocarcinoma. Which of the following intraoperative findings would indicate unresectability?
A.Fibrotic reaction in the body and tail of the pancreas
B.Microscopic tumor cells in peripancreatic lymph nodes on frozen section
C.Inability to develop an avascular plane anterior to the superior mesenteric vein
D.Cholelithiasis
Answer: c
During performance of pancreaticoduodenectomy, the lesser sac is opened widely through the gastrocolic omentum. This maneuver allows inspection of the body and tail of the gland to determine the extent of the tumor involvement and allows examination of lymph nodes along the superior and inferior body of the pancreas and around the celiac axis.
Enlarged nodes in these areas should undergo biopsy and be submitted for frozen-section examination, since tumor in these areas is beyond the bounds of standard pancreaticoduodenectomy and constitutes a contraindication to resection. If there is no evidence of lymphadenopathy, a dissection between the anterior surface of the portal vein and the posterior surface of the neck of the pancreas is performed. Ordinarily, only thin areolar tissue lies between the pancreas and the portal vein, and a communication behind the neck of the pancreas can be established. If there is hard tissue intervening and such communication cannot be established, this implies invasion of the anterior surface of the portal vein and signals unresectability by standard methods.
----------------------------------------------------------------------------------------------------------------
48.A 67-year-old male presents with complaints of itching, dark urine, and epigastric pain. Physical examination reveals jaundice. Initial laboratory tests show total bilirubin of 6.5 mg/dL, alkaline phosphatase elevated at 3 the upper limit of normal, and mild elevations in serum transaminases. Appropriate management includes which diagnostic test next?
A.Abdominal ultrasonography
puted tomography of the abdomen
C.Magnetic resonance imaging of the abdomen
D.Endoscopic retrograde cholangiography
Answer: A
Standard transcutaneous ultrasonography is the appropriate first test in the evaluation of the patient with jaundice, because the presence of a dilated common bile duct or intrahepatic bile ducts is essentially diagnostic of extrahepatic biliary obstruction. This finding directs the physician to a search for the cause of the obstruction. If the bile ducts are not dilated, mechanical obstruction is unlikely and the diagnostic thrust should move toward hepatocellular disease. Ultrasonography is also the best test to determine whether gallstones are present; this is extremely important because choledocholithiasis is one of the conditions most likely to cause jaundice in the elderly population.
49.The most common cause of death in the postoperative period following pancreaticoduodenectomy is which of the following?
A.Myocardial infarction
B.Intraperitoneal hemorrhage
C.Pulmonary embolism
D.Pneumonia
Answer: B
Pancreaticoduodenectomy is a formidable operation, and until recently, average operative mortality was reported to approximate 20%. In the past few years, several centers have reported large series with operative mortalities lower than 5%.
The most dreaded complication of pancreaticoduodenectomy is disruption of the pancreaticojejunostomy, which occurs in about 10% of patients. Anastomotic breakdown may lead to the development of an upper abdominal abscess or may present as a external pancreatic fistula. In its most virulent form, disruption leads to necrotizing retroperitoneal infection which may erode major arteries and veins of the upper abdomen, including the portal vein or its branches or the stump of the gastroduodenal artery. Impending catastrophe is often preceded by a small herald bleed from the drain site. Such an event is an indication to return to the operating room to widely drain the pancreaticojejunostomy and to repair the involved blood vessel. Open packing of the wound may be necessary in controlling diffuse necrosis and infection. On rare occasions, completion pancreatectomy is required to control sepsis. Intraperitoneal hemorrhage is the most common cause of death from pancreaticoduodenectomy.
50.A 45-year-old woman is evaluated for epigastric and back pain. Physical examination is normal. Computed tomography of the abdomen reveals a 8 cm cystic lesion in the region of the tail of the pancreas. The cyst demonstrates internal septations and papillary projections from its walls. Which of the following diagnoses is most likely in this patient?
A.Pancreatic lymphoma
B.Retroperitoneal liposarcoma
C.Pancreatic pseudocyst
D.Pancreatic mucinous cystadenoma
Answer: d
Mucinous cystic neoplasms account for about 2% of pancreatic exocrine tumors. Most patients with mucinous cystic tumors present with abdominal pain or an abdominal mass. There may be associated weight loss, steatorrhea, or diabetes. The diagnosis is best made by CT scanning and ultrasonography, which demonstrate a mass containing fluid-filled structures and internal septations. Occasionally, it is possible to see the papillary tumor excrescences on the cyst walls.
The tumor occurs six times as often in females as in males. About 80% of the tumors are located in the body and tail of the pancreas. They present as large (average, 10 cm), soft, and somewhat irregular tumors. Microscopically, the cysts are lined by columnar epithelium which contains mucin. Although most of the cells may appear benign histologically, most tumors larger than 3 cm contain areas of premalignant or malignant change and all mucinous cystic tumors should be considered to have malignant potential.
==============================================================
51.A 45-year-old woman develops upper gastrointestinal hemorrhage. Evaluation by upper endoscopy reveals three ulcers in the second portion of the duodenum. Bleeding is controlled using an endoscopic heat probe. Further investigation reveals a serum gastrin value of 240 pg/mL. Which of the following is false about diagnosis of gastrinoma?
A.An increase of more than 200 pg/mL in serum gastrin upon intravenous infusion of secretin.
B.An increase of more than 200 pg/mL in serum gastrin upon intravenous infusion of CCK.
C.Gastric acid analysis demonstrating basal acid secretion of 15 mEq/h
D.Enlarged gastric rugae on upper gastrointestinal contrast study
Answer: B
The indications for the measurement of gastrin include the presence of peptic ulcer disease, patients with prolonged undiagnosed diarrhea, patients within MEN-1 families and patients with prominent gastric rugal folds on upper GI series. In most patients with gastrinoma, the fasting serum gastrin level is elevated above 200 pg/ml. Gastrin values over 1000 pg/ml are virtually diagnostic of gastrinoma. However, fasting hypergastrinemia alone is not sufficient for the diagnosis of gastrinoma. Gastric acid analysis is an important test in the evaluation of patients with suspected gastrinoma, as it can differentiate between ulcerogenic causes of hypergastrinemia and nonulcerogenic causes of hypergastrinemia. The diagnosis of gastrinoma is supported by a basal acid output above 15 mEq/hour in nonoperated patients.
Following documentation that hypergastrinemia is associated with excessive acid secretion, provocative testing using secretin should be performed to differentiate between gastrinoma, antral G cell hyperplasia/hyperfunction, and the other causes of ulcerogenic hypergastrinemia. The secretin stimulation test is carried out in the fasting state by obtaining peripheral serum samples for gastrin in the basal period, administering secretin (2 units/kg body weight) as an intravenous bolus, and obtaining serum samples for gastrin at five minute intervals for 30 minutes. An increase in the gastrin level of more than 200 pg/ml above the basal level is supportive of the diagnosis of gastrinoma.
----------------------------------------------------------------------------------------------------------------
52.60 year old patient with an insulin/glucose ratio of 0.5 was documented at 28 hours of fasting. Symptoms of mental obtundation developed concurrently and were reversed by oral glucose administration. Endoscopic ultrasonography demonstrated a 1.2 cm mass in the head of the pancreas. Appropriate management consists of which of the following?
A.Surgical enucleation of the tumor
B.Total pancreatectomy
C.Long-term octreotide administration
D.Primary radiotherapy
Answer: A
The treatment of insulinoma is surgical in nearly all cases. Insulinomas are found evenly distributed within the pancreas, with approximately one-third being located in the head and uncinate process, one-third in the body of the gland, and one-third in the tail of the gland. Ninety percent of patients will be found to have benign solitary adenomas amenable to surgical cure. Small benign insulinomas not in close proximity to the main pancreatic duct may be removed by enucleation, independent of their location within the gland. In the body and tail of the Pancreas: insulinomas greater than 2 cm in diameter, and those in close proximity to the pancreatic duct are most commonly excised by distal pancreatectomy. Large insulinomas deep in the head or uncinate process of the pancreas may not be amenable to local excision, and may require pancreaticoduodenectomy.
-----------------------------------------------------------------------------------------
53.A 57-year-old man with a history of Duke’s C colon cancer is being evaluated for a rising CEA. Which of the following statement(s) is FALSE concerning the use of CT scanning for this indication?
A.Conventional CT scanning will detect lesions well below 1 cm in size
B.CT arterio-portography involves immediate CT scanning after direct injection into both the common hepatic artery and superior mesenteric artery
C.A double helical (spiral) CT scan may eliminate the need for invasive angiography
D.Magnetic resonance imaging of the liver will add little to the workup of this patient
Answer: A
CT scanning has been used increasingly to screen for hepatic and other intra-abdominal or retroperitoneal lesions. Conventional CT scanning includes 0.5–1 cm axial images of the liver after oral administration of barium and bolus injection of intravenous contrast. Although resolution has improved, hepatic lesions below 1 cm in size or lesions that are isodense with hepatic parenchyma may be missed. Resolution of hepatic lesions has been greatly enhanced by the combination of visceral angiography and CT scanning, known as CT arterio-portography (CTAP). Immediate CT scanning after injection of contrast directly into the common hepatic artery may identify small hepatic lesions which usually show increased density relative to the surrounding hepatic parenchyma. CT arterio-portography also includes direct injection of contrast into the splenic or superior mesenteric arteries, with CT imaging during the portal venous phase of this injection. Hepatic lesions supplied by the hepatic artery thus appear as discrete hypodense lesions surrounded by normal hepatic parenchyma enhanced by portal venous contrast. Recently, double helical (spiral) CT scanning has become available and shows considerable promise to complement or replace CTAP for preoperative imaging. This technique allows total hepatic imaging in both the arterial and arterial/venous phases after a single rapid bolus injection of intravenous contrast during a single breath hold by the patient. It is possible to visualize the portal structures and hepatic veins on a single scan and give a high resolution of small hepatic lesions. In addition, three-dimensional reconstructions can be created to further delineate hepatic parenchyma and demonstrate a CT constructed hepatic arteriogram. This technique may completely replace the need for invasive arteriography to characterize the blood supply to the liver prior to hepatic resection or after hepatic transplantation. Magnetic resonance imaging of the liver has results similar to CT scanning, but to date has not demonstrated improvements sufficient to justify the increased cost associated with the technique.
-----------------------------------------------------------------------------------------------------------------
54.The following statement(s) concerning hepatic bile formation/secretion are true EXCEPT.
A.The adult human liver secretes about 1500 cc of bile daily
B.Most bile is secreted by hepatocytes (canalicular bile)
C.Primary bile acids include cholic acid, chenodeoxycholic acid, and deoxycholic acid
D.The enterohepatic circulation is tremendously efficient in reabsorption of intestinal bile acids
E.Bile acids are the primary determinant of bile flow.
Answer: c
The adult human liver secretes about 1.5 liters of bile daily. Eighty percent of this volume is secreted by the hepatocytes (canalicular bile) and 20% is secreted by the bile duct epithelial cells (ductular bile). Solutes constitute about 3% of bile. The major solutes are conjugated bile acids, phosphatidyl choline, cholesterol, protein and bilirubin. Bile acids are the main determinant of bile production, and canalicular bile flow is traditionally divided into bile acid-dependent and bile acid-independent components. Primary bile acids are synthesized from cholesterol in the liver and in humans consist of cholic acid and chenodeoxycholic acid. Secondary bile acids are formed in the intestinal lumen by bacterial dehydroxylation and consist of deoxycholic acid and lithocholic acid derived from cholic acid and chenodeoxycholic acid, respectively. Essentially all primary and secondary bile acids are conjugated with the amino acids glycine or taurine. The human liver synthesizes 300 to 400 mg per day of bile acids from cholesterol, or about 10% of the total bile salt pool. Normally intestinal bile acids are efficiently (about 95%) taken up by the enterohepatic circulation. Luminal bile acids are transported by carrier proteins in the distal ileum and appear in the portal venous effluent. The hepatocyte extracts more than 95% of portal venous bile acids for resecretion into the bile.
55.A surgeon is suspected of having contacted hepatitis B virus via needle stick. Which of the following statement(s) is FALSE concerning his diagnosis and outcome?
A.Incubation of hepatitis B virus is about 8 weeks
B.Jaundice is the first serologic indicator of hepatitis B infection
C.The patient has about a 10% chance of developing a chronic carrier state
D.All susceptible household or sexual contacts of the surgeon should receive hepatitis B viral vaccine
Answer: B
Hepatitis B viral infection is insidious. The incubation period of the virus is about eight weeks. The first serum indicator of infection by hepatitis B virus is detection of the serum hepatitis B surface antigen (HBsAg) which may proceed the onset of jaundice. In most cases, hepatitis B infection is self-limited and does not progress to chronic hepatitis. However, some 10% of patients with acute hepatitis B viral infection, whether it is clinical or subclinical, will develop a chronic carrier state. The carrier state is defined by the presence of HBsAg in serum for longer than six months. The best method of treatment of hepatitis B viral infection is primary prevention by vaccination. All susceptible household or sexual contacts of a person with a positive serum test for HBsAg should be advised to receive a full course of hepatitis B viral vaccine. Passive prophylaxis with hepatitis B immunoglobulin should be provided to any susceptible contact in whom there is recent potential parenteral exposure such as an accidental needle stick.
-------------------------------------------------------------------------------------------------------------
56.The following statement(s) is FALSE concerning hydatid cysts.
A.Percutaneous aspiration is an important aspect of diagnosis and treatment of a hydatid cyst.
B.CT scan will oftentimes show the classic findings of a cystic liver lesion with a calcific rim.
C.At operation, care must be taken to protect the operative field from spillage of the cyst fluid
D. Hydatid cysts are most commonly the result of infection with the tape worm, Echinococcus granulosis
Answer: A
Hydatid cysts are most commonly the result of infection with the tape worm, Echinococcus granulosis. Routine laboratory tests in patients with hydatid cysts are normal or nonspecifically abnormal. Although routine chest or abdominal radiographs may show a mass with a calcific rim, sonography and CT scan are the favored means of imaging hydatid cysts. The presence of calcifications and daughter cysts within the parent cyst suggests Echinococcus. Percutaneous needling of a hydatid cyst is unwise unless precautions against anaphylaxis are undertaken. A cyst’s fluid is often under pressure, and needling may precipitate rupture with the potential for anaphylaxis or intraperitoneal seating. The classic treatment of hydatid cysts is operative. The surgical aim is to remove the cyst or cysts without dissemination of the organism. At operation, the cyst is drained of fluid through a cannula after carefully protecting the operative field from fluid leakage. If the aspirate is clear a parasiticidal fluid (ethyl alcohol or 20% sterile saline) is injected into the cyst to kill any adherent scoleces. The cyst contents and the pericystic wall is then removed with careful surgical dissection.
-----------------------------------------------------------------------------------------------------------------
57.Which of the following statement(s) is FALSE concerning treatment of pyogenic liver abscess?
A.Antibiotic therapy alone may be advisable in patients with multiple small abscesses
B.Percutaneous drainage provides comparable results to surgical drainage in patients with unilocular large abscesses
C.Sufficient antibiotic coverage for most hepatic abscesses includes coverage for gram-positive aerobic bacteria only.
D.In patients with a primary biliary origin for the hepatic abscess, treatment must also be addressed at underlying biliary pathology such as choledocholithiasis or biliary ductal obstruction.
Answer: C
The preferred treatment of most patients with hepatic abscesses is broad-spectrum antibiotic coverage and drainage. A number of studies have demonstrated for most patients with large unilocular abscesses that percutaneous catheter drainage is as effective as surgical drainage. Bacteria that predominate in pyogenic liver abscesses are gram-negative aerobes, streptococcal species, and anaerobes. Therefore, broad-spectrum antibiotic coverage is necessary. Antibiotic coverage alone may be advisable in occasional patients who have multiple small abscesses not accessible to percutaneous or surgical drainage. Since many of these patients have an underlying biliary pathology as the source of the hepatic abscess, correcting this underlying pathology, for example, establishing biliary drainage surgically or nonoperatively is important.
58.Which of the following statement(s) is true concerning acute, fulminant hepatic failure?
A.The most frequent cause of acute hepatic failure world-wide is hepatitis B infection
B.Higher grades of encephalopathy are associated with a worse prognosis
C.Hypoglycemia is a common complication of all liver diseases
D.Liver transplantation would appear indicated in all patients with hepatic coma secondary to acute liver failure
Answer: B
The diagnosis of acute (fulminant) hepatic failure is based on the development of encephalopathy within eight weeks of the onset of symptoms. The overall prognosis is poor, but the hepatic lesions are potentially reversible, and recovery can lead to restoration of normal liver function. The most frequent cause of acute hepatic failure world-wide is non-A, non-B viral hepatitis. A variety of other viral agents and hepatotoxins can also cause this condition.
No reliable criteria predict outcome and response to treatment. Higher grades of encephalopathy (depth of coma) on admission are associated with the worst prognosis. Management should include general supportive measures and specific treatment for hepatic encephalopathy, cerebral edema, electrolyte and metabolic disturbances, infection, and pain. Hypoglycemia is an unusual complication of most liver diseases except in patients with acute hepatic failure or hepatic neoplasms. The enormous reserve capacity of the liver accounts for the rarity of hypoglycemia except as a preterminal event. Bleeding is also a frequent cause of death in patients with acute hepatic failure secondary to depressed liver synthesis of clotting factors and qualitative or quantitative platelet disorders. The lack of a definitive medical treatment for acute hepatic failure makes liver transplantation seem attractive especially for patients with little or no chance of recovering normal liver function. Perhaps the most significant drawback to widespread acceptance of liver transplantation for acute hepatic failure is the lack of criteria reliability to predict which patients are likely to benefit from operation. Patients with mild to moderate degrees of coma are likely to recovery spontaneously without the need for liver transplantation while rapid deterioration and neurologic status to grade III or grade IV coma are associated in some centers with a mortality of 95%.
59.Which of the following statement(s) is true concerning the use of transjugular intrahepatic portosystemic shunts (TIPS) in the treatment of variceal bleeding?
A.This procedure effectively creates an end-to-side portocaval shunt
B.Procedure-related mortality is generally in excess of 20%
C.TIPS has been used successfully as a pretransplant procedure to reduce portal pressure
D.The placement of a TIPS is not associated with the development of encephalopathy
Answer: C
Transjugular intrahepatic portosystemic shunts (TIPS) refer to an implantable, expandable metal stent placed radiologically through the hepatic parenchyma to establish a track between branches of the hepatic and portal veins. TIPS results in similar hemodynamics as a side-to-side portal systemic shunt. There is firm clinical data that TIPS provides effective control of acute variceal hemorrhage and portal hypertension regardless of the etiology of the underlying liver disease or the degree of hepatic decompensation. TIPS has also been used for preoperative portal decompression to facilitate orthotopic liver transplantation. Pretransplant TIPS should reduce portal pressure thereby reducing operative time and blood loss. The major complications of TIPS include encephalopathy and stenosis or occlusion of this stent. Encephalopathy occurs in 10% to 20% of patients after TIPS. This complication appears to correlate with increasing age of the patient and increased shunt diameter and shunt flow.
60.Hepatic encephalopathy is a common systemic manifestation of chronic liver disease. Which of the following statement(s) is FALSE concerning this condition?
A.Blood ammonia levels correlate well with the stage of hepatic encephalopathy
B.Alterations in central nervous system neurotransmitters such as the neurotransmitter g- aminobutyric acid (GABA) have been proposed in the pathogenesis of hepatic encephalopathy
C.Lactulose can be used to decrease intestinal ammonia absorption
D.Patients can be expected to have an increased sensitivity to benzodiazepines
Answer: A
Hepatic encephalopathy, a poorly explained neuropsychiatric syndrome, characterized by diverse neurologic abnormalities, is the pathologic evidence of nonspecific structural changes in neurons, and a variable prognosis. Several hypotheses to explain the pathogenesis of hepatic encephalopathy have been proposed. Ammonia has been widely implicated in the pathogenesis of hepatic encephalopathy despite conflicting evidence. Blood ammonia levels correlate poorly with the stage of encephalopathy, however, one of the mainstays of treatment is measures to decrease ammonia absorption from the gut including the oral administration of lactulose. Another hypothesis has implicated false neurotransmitters in the pathogenesis of hepatic encephalopathy. Evidence suggests that activation of the GABA system may be important in the pathogenesis of hepatic encephalopathy. The GABA receptor binds several classes of ligands including GABA and drugs such as benzodiazepines. For reasons that are unclear, hepatic failure appears to increase the brain density of GABA receptors. This observation may explain the increased sensitivity to benzodiazepines and other inhibitory neurotransmitters observed with patients with chronic liver disease.
61.Which of the following statement(s) is NOT true concerning the prognosis of patients with hepatic metastases and colorectal carcinoma?
A.Over half of these patients will survive one year without treatment
B.Five year survivals following hepatic resection for an isolated metastasis is in excess of 25%
C.Survival beyond five years after resection suggests a high probability of cure
D.Survival rates are improved with a margin of resection greater than 1 cm
E.The size of a liver metastasis is not a significant factor in predicting recurrence if adequate margins can be obtained
Answer: A
Studies consistently report five-year survival rates averaging 25% for hepatic resection for colorectal metastases. Those who survive beyond five years seem to do well with only an additional 5% dying of recurrence within the next five years. Median survival of patients with untreated metastases is on the order of three to 10 months, with only 20% surviving past one year. Overall survival is significantly improved with surgical margins greater than 1 cm with decreased survival in patients with positive margins or margins less than 1 cm in size. The number of metastasis is a less consistent but statistically significant factor. Patients with four or more metastases have a poorer prognosis. As for the size of the metastasis, it is not a significant factor except that a larger total liver volume of metastasis requires a larger hepatic resection. Larger size may preclude adequate margins and indicate longer development of time with an increased likelihood of micrometastases.
62.Which of the following statement(s) is true concerning Emergency Room thoracotomy?
A.Overall survival rates approach 25%
B.Blunt trauma patients without signs of life upon arrival in the Emergency Room are candidates for Emergency Room thoracotomy
C.All patients with penetrating trauma to the chest and the absence of vital signs are candidates for ER thoracotomy
D.None of the above
Answer: D
A recent meta-analysis of 24 reports concerning the outcome of Emergency Room thoracotomy found that the overall survival rate was 11%. There were no survivors among patients with no signs of life (supraventricular electrical activity, pupillary reaction, and agonal respirations) at the scene. In addition, there were no neurologically intact survivors among blunt trauma patients without signs of life upon arrival in the Emergency Department. Considering these findings, an appropriate algorithm would indicate that Emergency Room thoracotomy for penetrating trauma is indicated only if patients had signs of life at the scene and had lost signs of life less than five minutes prior to arrival in the Emergency Room. Blunt trauma patients would be allowed Emergency Room thoracotomy only if the patient had signs of life upon arrival at the Emergency Room. If patients meet these criteria and lose cardiac function, airway placement and fluid resuscitation is initiated simultaneously with or immediately followed by left anterior thoracotomy, pericardiotomy, and internal cardiac massage.
63.Which of the following statements is FALSE concerning injuries to the chest wall?
A.The mortality rate currently associated with sternal fractures is as high as 35%
B.The severe ventilatory insufficiency associated with a flail chest is due to the paradoxical motion of the involved segment of chest wall
C.In most cases of an open pneumothorax, or sucking chest wound, surgical closure is necessary
D.Persistent chest tube bleeding at a rate greater than 200 ml/hour for four hours, or greater than 100 ml/hour for eight hours is an indication for thoracotomy for control of hemorrhage
E.A 20% incidence of splenic injury is associated with fractures of ribs 9, 10 and 11 on the left
Answer B
Rib fracture is the most common injury associated with blunt chest trauma and may occur directly at the site of force or laterally as the result of significant antero-posterior compression of the chest. The location area of the rib fracture may be indicative of associated injuries. A 20% incidence of splenic injury is associated with fracture of ribs 9, 10, and 11 on the left with a similar association with right lower rib fractures and hepatic parenchymal injuries. The mortality rate associated with sternal fractures in older series was as high as 25–30%, mainly because of other injuries to the chest, such as aortic transection, cardiac contusion, tamponade or tracheo-bronchial rupture. More recent studies have suggested a change in the pattern and severity of injuries associated with sternal fracture. Widespread improvements in automobile safety have likely contributed to this change such that isolated sternal fractures may result from shoulder belt use and may not necessitate hospital admission in the stable patient. A flail chest occurs when consecutive ribs are fractured in more than one place, creating a free-floating segment of the chest wall. The creation of a free-floating segment may result in paradoxical chest wall motion with respiration. The intact chest wall expands during inspiration, but the negative intrathoracic pressure generated causes the flail segment to move inappropriately inward. Historically it was believed that the paradoxical motion was the cause of severe ventilatory insufficiency associated with the flail chest. Gradually, understanding of the pathophysiology of the flail chest has evolved. The ventilatory impairment is not simply due to paradoxical motion of the chest wall, but rather due to underlying pulmonary parenchymal injury in combination with the hypoventilation and splinting that results from the pain of multiple contiguous rib fractures. The open pneumothorax, or sucking chest wound, is an uncommon injury usually caused by impalement, high-speed motor vehicle accident, or shotgun blast, which causes a large chest wall defect. The diagnosis of a sucking chest wound can be made on simple inspection of the chest wall and hearing the flow of air through the wound. The defect should be occluded immediately with an impermeable dressing, essentially converting the situation to a closed pneumothorax. Tube thoracostomy is then performed to re-expand the lung. The chest wall defect usually requires operative debridement and formal chest wall closure. A hemothorax is the accumulation of blood in the pleural space and it occurs in 50–75% of patients with severe blunt or penetrating chest trauma. Massive hemothorax (i.e., larger than 1000–1500 ml) may require thoracotomy. Persistent bleeding, at a rate of > 200 ml/hour for four hours, or > 100 ml/hour for eight hours, is also an indication for thoracotomy. If the patient manifests any hemodynamic instability during the period of observation, urgent thoracotomy is mandatory.
64.A 22-year-old male driving a car at a high speed and not wearing a seatbelt, leaves a road and crashes with a full frontal impact into a tree. ALL of the following injury patterns ARE predictable from this type of motor vehicle accident EXCEPT?
A.Orthopedic injuries involving the knees, femurs, or hips
B.Laceration to the aorta
C.Hyperextension of the neck with cervical spine injury
DDiaphragmatic rupture due to marked increase in intraabdominal pressure
Answer: D
With frontal impact, when the vehicle stops abruptly, unrestrained front-seat occupants move in one of two predictable pathways—down and under the dashboard or up and over the steering wheel. With the former movement, the knees strike the dashboard, and the upper legs absorb the primary energy transfer. Dislocated knees, fractured femurs, and posterior fracture dislocation of the hips are expected injuries. After the knees impact, the upper body flexes forward and up and over the steering wheel. The chest or abdomen impacts the steering wheel and the head impacts the wind shield.
Predictable injury patterns following the up-and-over component of a frontal impact include the following: 1) anterior chest wall compression; 2) compression injuries to both hollow and solid abdominal viscera; 3) shear injuries such as lacerations to the aorta or liver, kidneys or other solid viscera; 4) injury to the brain from direct compression with scalp lacerations, skull fractures and cerebral contusions or from deceleration or shear forces; 5) acute neck flexion, hyperextension or both resulting in cervical spine injury.
Three-point passenger restraints and air bags, although overall very effective in reducing injury, can cause specific related injuries. Common injuries when lap belts are incorrectly strapped above the anterior iliac spine include compression injuries of intraabdominal organs (liver, pancreas, spleen, small bowel, large bowel), increased intraabdominal pressure and diaphragmatic rupture.
65. The clinical and histologic signs of invasive burn wound infection include ALL EXCEPT?
A. Focal dark red or dark brown discoloration of the eschar.
B. Delayed separation of the eschar.
C. Conversion of an area of partial-thickness burn to full-thickness necrosis.
D. The presence of micro-organisms in the unburned subcutaneous tissue in a burn wound biopsy specimen.
Answer: B
It is essential to examine the entire burn wound at the time of the daily cleansing to identify invasive burn wound infection at the earliest possible time. The appearance of focal areas of dark red or dark brown discoloration are the most common changes indicative of burn wound infection, but similar changes may be caused by hemorrhage due to local trauma or maceration. Accelerated separation of the eschar is often produced by burn wound infections, but delayed separation of the eschar is indicative of effective control of the microbial population in the burn wound. Conversion of an area of partial-thickness burn to full-thickness necrosis is the most reliable clinical sign of invasive burn wound infection. Identification of such a change mandates histologic examination of a burn wound biopsy, which is the only reliable means of differentiating the colonization of nonviable tissue from the invasion of viable tissue. Identification of micro-organisms in the unburned viable tissue of a burn wound biopsy confirms the diagnosis of invasive burn wound infection. Microbial migration along the skin appendages, terminal nerve radicles, and thrombosed capillaries in the eschar and heavy growth of micro-organisms in the subeschar space are manifestations of the colonization of nonviable tissue and represent the mechanisms by which eschar separation occurs.
66.Valid points in the management of burns on special areas include:
A.The large majority of genital burns are best managed by immediate excision and autografting
B.All digits with deep dermal and full-thickness burns should be immobilized with six weeks of axial Kirschner wire fixation
C.Deep thermal burns of the central face are best managed with immediate excision and autografting
D.Burns of the external ear are commonly complicated by acute suppurative chondritis if topical mafenide acetate is not applied
Answer: D
Because of the thickness and deep appendages of the skin of the central face, relatively deep burns of these areas frequently heal. This is fortunate, because it is difficult to achieve a favorable result with primary excision and grafting of the central face. Management of the burned hand is dictated by the depth of injury. Superficial burns are managed with elevation, topical antimicrobials, and full passive range of motion for each joint twice daily. Deep, partial and full-thickness injuries are best managed by excision and sheet grafting as soon as practical. Hands are immobilized in a functional position for seven days after surgery before passive and active therapy is resumed. Fourth degree hand burns, which involve the underlying extensor mechanism, joint capsules or bone are significantly more difficult management problems and are managed by staged sheet autografting and often benefit from temporary axial Kirschner wire fixation of open and unstable interphalangeal or metacarpophalangeal joints. Burns of the external ear are treated with twice daily cleansing and application of mafenide acetate. Deep burns of the external ear are commonly complicated by acute suppurative chondritis if topical mafenide acetate is not applied. In general, the practice for deep genital burns is to manage these limited surface area injuries with topical therapy for a period of two to three weeks unless the wounds are remarkably deep. Unhealed injuries are debrided and grafted with sheet autograft at this time, with generally excellent cosmetic and functional results.
67.ALLof the following are accepted adjuncts in the management of hypertrophic scar
EXCEPT?
a. Local steroid injection
b. Compression garments
c. Topical silicone
d. Release or excision with autografting
e. Topical platelet-derived growth factor
Answer: E
Hypertrophic scar formation is a major source of long-term morbidity after burns. All healed and grafted burns become hypervascular shortly after successful epithelialization. Wounds destined to become hypertrophic develop a second surge of neovascularization between 9 and 13 weeks. Wounds that are most commonly associated with hypertrophy are deep dermal burns that heal in three or more weeks and full thickness wounds that heal by contraction and epithelial spread from wound edges. Current tools used in the prevention of hypertrophic scars include compression garments, topical silicone sheets, steroid injections, and release or excision and autografting.
68.Which of the following statement(s) is true concerning carbon monoxide and cyanide exposure?
A.A normal oxygen saturation by standard transmission pulse oximetry precludes the possibility of significant carboxyhemoglobinemia
B.Most patients with cyanide exposure require administration of sodium thiosulfate
C.The half-life of carbon monoxide is reduced by a factor of 5 with ventilation with 100% oxygen
D.Even if fire victims are well ventilated with high concentrations of oxygen by emergency response personnel from the time of extrication, carboxyhemoglobin values are frequently greater than 10% on initial evaluation
Answer: C.
Both carbon monoxide and cyanide are commonly inhaled by victims of closed space fires. Patients with significant amounts of carboxyhemoglobin suffer from a marked reduction in their ability to deliver oxygen to peripheral tissues despite a normal arterial partial pressure of oxygen. Its 2.5 hour half-life is reduced by a factor of 5 by ventilation with 100% oxygen. Fire victims who are well ventilated with high concentrations of oxygen by emergency response personnel from the time of extrication commonly have normal carboxyhemoglobin values (< 5%) on initial evaluation despite significant exposure to carbon monoxide at the time of injury. Carboxyhemoglobin is not sensed by standard transmission pulse oximetry, so a normal oxygen saturation on such a monitor does not preclude the possibility of significant carboxy-hemoglobinemia.
Hydrogen cyanide, which is commonly present in the smoke of structural fires, interferes with oxidative metabolism at the cellular level resulting in lactic acidosis. With proper ventilation and fluid resuscitation, the cyanide-induced acidosis corrects in most cases and specific treatment with sodium thiosulfate is not generally required.
69. Posttransplantation hypertension can be caused by all true except:
A. Rejection.
B. Cyclosporine nephrotoxicity.
C. Renal transplant artery stenosis (RTAS) in 50 % of cases.
D. Recurrent disease in the allograft.
Answer: C
Both acute and chronic rejection may result in hypertension. The former causes acute fluid retention and plugging of peritubular capillaries with inflammatory cells. This may progress to intimal swelling and medial necrosis and eventuate in ischemia secondary to endothelial proliferation and obliteration of small vessels. Chronic rejection, thought to be related to protracted humoral injury, results in obliteration of capillaries via the development of intimal hyperplasia. Cyclosporine has a vasoconstrictive effect which, through activation of the renin-angiotensin system, may lead to hypertension. RTAS is responsible for hypertension in 4% to 12% of renal allograft recipients. It responds well to percutaneous angioplasty. A careful trial of angiotensin-converting enzyme inhibitors may be diagnostic of RTAS. Recurrent disease such as membranoproliferative glomerulonephritis and focal glomerular sclerosis may result in significant hypertension in renal allograft recipients.
70. Which of the following statements about posttransplantation malignancy is correct?
A. Certain immunosuppressive agents increase the incidence of malignancy in transplant recipients, whereas others do not.
B. Those malignancies most commonly seen in the general population (breast, colon) are substantially more common in transplant recipients.
C. Lymphoproliferative states and B-cell lymphomas are associated with Epstein-Barr virus.
D. None of the above.
Answer: C
Both naturally occurring and iatrogenic states of immune deficiency are associated with an increased rate of de novo malignancy. Transplant recipients have a rate of malignancy approximately 100 times that of the normal population. The degree of immunosuppression, rather than a specific immunosuppressive agent, appears to be responsible. Squamous and basal cell carcinomas of the skin are most common; however other tumors that are common in the general population, such as breast and colon cancers, do not appear to be increased in incidence. Lymphomas, which occur at a rate that is 350 times normal, and the lymphoproliferative states that often precede them appear to be associated with Epstein-Barr virus. Possible explanations for these high malignancy rates include defective immunosurveillance, chronic stimulation of the reticuloendothelial system by the allograft, the carcinogenic effect of immunosuppressive drugs, and viral oncogenesis.
-------------------------------------------------------------------------------------------------------------
71.One week after receiving a cadaver renal allograft, the recipient remains oliguric and dialysis dependent. Ultrasonography reveals a larger perigraft fluid collection. Your next step in management includes:
A. No further investigations (since perigraft collections are fairly common after renal transplantation).
B. Aspiration of the perigraft fluid collection and instillation of a fibrosis-inducing agent to obliterate the dead space.
C. Angiography for localization of a bleeding site in the renal allograft.
D. Aspiration of the perigraft fluid collection for chemical analysis.
Answer: D
Urine leaks usually occur early after transplantation, and the most frequent site of leakage is from the ureteroneocystostomy or ischemic ureter. The clinical signs are pain, swelling, and deterioration of renal function before leakage from the wound is observed. Aspiration of the perigraft fluid collection for chemical analysis of blood urea nitrogen (BUN) and creatinine would aid the differentiating urinoma from lymphocele. The composition of urinoma reveals BUN and creatinine concentrations several orders of magnitude higher than those of a lymphocele, which are comparable to the values in blood.
72. Which of the following is the one true statement about acute rejection.
A. Acute rejection is mediated by T lymphocytes.
B. Acute rejection is mediated by preformed cytotoxic antibody.
C. Acute rejection most frequently occurs over months.
D. Acute rejection is mediated by both T cells and B cells .
Answer: A
Acute rejection is mediated primarily by T lymphocytes. It occurs over 1 to 3 weeks after placement of an allograft. Hyperacute rejection is mediated by preformed cytotoxic antibody. It occurs within 48 hours of placement of a graft. Chronic rejection is mediated by both T cells and B cells and occurs over months.
73.Advantages of split-thickness skin grafts over full-thickness skin grafts include:
A. Split-thickness grafts include only part of the epidermis and none of the dermis.
B. Split-thickness grafts offer better pigment matching.
C. Split-thickness grafts offer better resistance to contraction.
D. Split-thickness grafts offer better resistance to infection.
Answer: D
Split-thickness grafts include all of the epidermis but only a part of the dermis. Full-thickness skin grafts include all of both layers, so surgical closure of the donor wound is necessary whereas the portion of dermis left at the split-thickness skin donor site regenerates a skin covering. Because all layers of the skin are included in a full-thickness skin graft, pigment matching is better and less contraction occurs than with split-thickness grafts. Full-thickness grafts require a better blood supply for survival than the split-thickness grafts because the graft vessels are cut below the level of the dermal branching. Relatively fewer cut vessels are available to absorb nutrients from the wound bed to meet the relatively greater nutritional needs of the thicker graft. The poor resistance of full-thickness grafts to infection precludes their use on contaminated wounds, whereas split-thickness skin, which is more richly supplied with open blood vessels on its underside, is able to survive on compromised surfaces, including granulating wounds contaminated with bacteria.
---------------------------------------------------------------------------------------------------------
74.The most commonly used substitutes for peripheral arteries are:
A. Dacron grafts.
B. Expanded polytetrafluoroethylene (Gore-Tex) grafts.
C. Internal, external, and/or common iliac artery autografts.
D. Bovine carotid artery xenografts.
E. Saphenous vein autografts.
Answer: E
The greater saphenous vein has proved to be the most satisfactory and most commonly used arterial substitute. The wall is sufficiently strong to withstand arterial pressures without becoming dilated or aneurysmal, yet is flexible and easily sutured. The diameter is sufficiently great to avoid thrombosis and nourishment is provided by the intraluminal blood flow. The smooth, natural endothelial lining is less thrombogenic than any known synthetic surface. The lining surface heals itself and may sequester white cells to fight infection, unlike Dacron grafts, which provide a haven for infecting organisms in the interstices of their synthetic fibers. Saphenous vein autografts heal even when placed into the infected bed of a previous synthetic graft.
75. Several types of gastrointestinal autografts have been used to replace the esophagus after extirpation of carcinomas. Successful reconstructions have been achieved most frequently with:
A. Stomach.
B. Jejunum.
C. Ileum.
D. Ascending colon.
E. Descending colon.
Answer: A
Although all of the listed bowel segments have been used successfully for reconstruction of the esophagus following removal of carcinomas, the stomach remains the most frequently used autograft for esophageal reconstruction. Because of its excellent blood supply the procedure can be performed at little risk as a single operation and achieve satisfactory long-term relief of dysphasia in at least 90% of patients. Either the entire stomach can be drawn into the chest or a gastric tube created in an isoperistaltic or antiperistaltic manner of sufficient length to reconstruct the entire esophagus. The advantages of a mucosal lining, serosal covering, natural opening into the stomach, and excellent blood supply based on the gastroepiploic vessels make the stomach the autograft of choice in most situations
76.Which of the following statement(s) is true concerning renal transplantation?
A.Living-related donor transplants typically can be expected to have one-year graft survival rates of over 90%
B.Preconditioning of the recipient with the use of donor-specific blood transfusions from their living donor improves graft survival and therefore should be used routinely
C.Pre-transplant blood transfusions result in improved graft survival following cadaveric renal transplant in the cyclosporine era
D.Age of the recipient over 50 years is generally associated with a poorer outcome due to graft rejection
Answer: A
The use of living-related donor renal transplant has multiple advantages including improved short-and long-term graft survival, routine immediate allograft function, and fewer rejection and infectious episodes. Nearly all transplantation centers that perform living-related donor transplantations report one-year graft survival rates of over 90%. The use of preconditioning of the recipient with donor-specific blood transfusions from their living donor can improve graft survival. The major drawback to this maneuver is the development of recipient anti-donor antibodies (sensitization) which occurs in nearly one-third of recipients. The development of sensitizing antibodies eliminates the use of that donor. With the introduction of cyclosporine, the use of donor-specific transfusions with subsequent immunosuppression, was compared to nontransfused recipients treated with cyclosporine and prednisone. These investigations have demonstrated excellent graft survival rates over long-term follow-up and therefore routine donor-specific transfusions are seldom performed in adults. In the azathioprine and prednisone immunosuppression era, several immunologic and nonimmunologic risk factors were identified as having an adverse effect on graft outcome. Historically, older renal allograft recipients (older than 50 years) did poorly compared with younger counterparts. Much of the graft loss was found to be associated with patient deaths, and usually was the result of overwhelming infection. With the cautious use of cyclosporine and prednisone, however, excellent patient and graft survival rates are now reported. Data from the azathioprine and prednisone era show a clear-cut benefit from improved graft survival after multiple random blood transfusions. More recent studies again showed no advantage to blood transfusion when cyclosporine is used. Since transfused patients have a risk of developing anti-HLA antibodies, these patients may become more difficult to undergo organ transplantation in a timely fashion.
------------------------------------------------------------------------------------------------------
77.Which of the following statement(s) is FALSE concerning clinical syndromes of rejection?
A.Hyperacute rejection occurs with kidney, heart, liver and lung transplants
B.The histologic characteristics of acute rejection include lymphocyte infiltration accompanied by plasma cells, eosinophils, or neutrophils.
C. Chronic rejection is the major cause of graft failure and patient loss
D.Transplantation across major ABO incompatibility will result in hyperacute rejection of a renal or cardiac transplant
Answer:A
Hyperacute rejection is the result of pre-formed antibody binding to the allograft at the time of revascularization in the operating room. Complement is activated resulting in endothelial cell destruction, vascular leak, recruitment of platelets and neutrophils, thrombosis of vessels, and destruction of the graft in a period of minutes to hours. Kidney, heart, pancreas, and lung allografts are all susceptible to hyperacute rejection; however, liver grafts are relatively resistant to this process and are often transplanted across antibody differences and even across an ABO difference. Acute rejection usually occurs days to weeks after transplantation and is initiated by T-cell dependent immunity characterized microscopically by lymphocytic infiltration accompanied by plasma cells, eosinophils, and a few Mast cells or neutrophils. Chronic rejection usually occurs months to years after transplant. It is characterized by loss of normal histologic structure, fibrosis and atherosclerosis. Chronic rejection is the major cause of graft failure and patient loss with all organs.
78.Excision rather than bypass is preferred for surgical treatment of small intestinal Crohn's because:
A. Excision is safer.
B. Bypass does not relieve symptoms.
C. Excision cures the patient of Crohn's disease but bypass does not.
D. Fewer early complications appear with excision.
E. The risk of small intestine cancer is reduced.
Answer: E
Bypass of segments of small bowel affected with Crohn's disease is a safe operation with few complications, and one that usually relieves symptoms promptly. It leaves diseased bowel behind, however, which can flare in the future and can develop carcinoma. Excision, though it does not cure the Crohn's disease, removes the areas of severe involvement and so eliminates the risk of developing cancers in these segments.
79.Which statements about anorectal Crohn's disease IS FALSE?
A. It may be the only overt manifestation of Crohn's disease.
B. It accompanies large intestine Crohn's more often than small-intestine Crohn's.
C. The anorectal disease may subside with metronidazole therapy alone.
D. It should not be treated operatively.
Answer: D
Anorectal Crohn's disease may be the sole gross manifestation of Crohn's disease. It more often accompanies large-intestinal Crohn's than small-intestinal Crohn's. When present with small-intestinal Crohn's, resection of the small-intestinal disease does not affect the course of the anorectal disease. The anorectal disease may subside with metronidazole therapy alone, but local conservative therapy, such as draining abscesses or unroofing anal fistulas, may also relieve symptoms and promote healing.
--------------------------------------------------------------------------------------------------------------
80.The most common indication for operation in Crohn's disease of the colon is:
A. Obstruction.
B. Chronic debility.
C. Bleeding.
D. Perforation.
E. Carcinoma.
Answer: B
Crohn's disease of the colon usually leads to operation because of chronic debility and inanition unresponsive to medical therapy. Obstruction, perforation, and bleeding are uncommon complications of colonic Crohn's. While for persons with Crohn's colitis the risk of carcinoma of the colon is four to six times that of a healthy control population, the presence of cancer in the colon is an unusual cause for operation for Crohn's colitis. In fact, most patients with Crohn's have their colons excised before sufficient time has elapsed for cancers to appear. Cancers usually do not appear until 10 years or more after the onset of disease.
=============================================================
81.Which of the following statements about surgical procedures on the colon and rectum is FALSE?
A. Successful healing of colonic anastomoses depends on the adequacy of the blood supply.
B. In excising part of the colon containing cancer, the lymphatics should be included by dividing the mesentery close to the mesenteric origin.
C. Despite complete removal of the colon and rectum, transanal fecal flow can be preserved by means of an ileal pouch–anal anastomosis.
D. When a colostomy is created it cannot be reversed.
E. Colostomy can be life saving in patients with colonic perforation or obstruction.
Answer: D
Healing of colonic anastomoses depends on the adequacy of blood supply, which in turn depends on the tension on the anastomosis. Oncologic principles for surgery of colon cancer dictate that the mesentery be divided as close as possible to the origin of the blood vessels, to include the lymphatic vessels and nodes draining that area. In patients at risk for colon cancer, such as those with ulcerative colitis or familial polyposis, the construction of an ileal pouch–anal anastomosis allows for transanal fecal flow despite complete excision of the colon and rectum. Colostomies can often be life saving, especially in patients with colon perforation or obstruction, and are usually reversed unless the patient requires abdominoperineal resection of the rectum for cancer.
-----------------------------------------------------------------------------------------------------------------
82.Which of the following statements about colon physiology is FALSE?
A. Colonic recycling of urea is accomplished by the splitting of urea by bacterial ureases.
B. Fermentation by colonic bacteria may rescue malabsorbed carbohydrates.
C. The preferred fuel of the colonic epithelium is short-chain fatty acids.
D. Absorption by the colonic mucosa is a passive process.
E. Insoluble fibers create bulk in the stool.
Answer: D
One of the functions of the colon is to recycle nutrients used in the digestive process, such as bile salts, water, and electrolytes. Urea reaching the colon via either the ileal effluent or the mucosal circulation is split by bacterial ureases. The reabsorbed ammonia is returned to the liver, where it is used for amino acid and protein synthesis. Fermentation is the anaerobic process by which bacteria can degrade carbohydrates and proteins. The normal substrate for colonic fermentation is dietary fiber, which resists degradation by alpha-amylases in the small intestine. Starch polysaccharides are normally degraded by amylases and absorbed in the small intestine; however, when starch polysaccharides are not adequately degraded and absorbed, they can also be fermented and the caloric value recovered as short-chain fatty acids. n-Butyrate, one of the short-chain fatty acids produced by bacterial fermentation, is the preferred fuel of the colonic epithelium. The colonic epithelium utilizes n-butyrate as a fuel for the absorption of sodium and water. Insoluble fibers retain water and are poorly fermented by bacteria, thus producing fecal bulk.
83.Which of the following patients generally does not require surgical intervention as a consequence of acute diverticulitis?
A. A 30-year-old man with no history of diverticulitis.
B. A 68-year-old man status 2 weeks post–renal transplantation.
C. A 65-year-old woman with hypertension and diabetes mellitus.
D. A 50-year-old man with pneumaturia.
E. A 46-year-old man with right-sided diverticulitis.
Answer: C
The majority of patients with diverticular disease are elderly and often have comorbid illnesses. The prognosis in these patients depends on the severity of the underlying inflammatory lesion. Certain subsets of patients, however, have been identified whose overall prognosis is worse. Patients younger than 40 years have a higher incidence of complications, as about 70% eventually require surgical intervention. Patients undergoing renal transplantation are routinely immunosuppressed. Such patients do not manifest the usual signs and symptoms of an inflammatory response. Delays in diagnosis and failure of the normal immune response mandates surgical intervention in virtually all of these patients. The presence of pneumaturia is strongly suggestive of a colovesical fistula. All such fistulas require resection of the diseased colon and repair the involved bladder. Patients with right-sided diverticulitis are usually misdiagnosed as acute appendicitis and, therefore, often are not diagnosed until laparotomy.
---------------------------------------------------------------------------------------------------------
84.Which of the following is true about colorectal polyps?
A. Familial juvenile polyposis is associated with an increased incidence of colon cancer.
B. Although the propensity for development of malignancy is related to the size of a neoplastic polyp, those with mixed tubulovillous histologic appearance are most likely to develop malignant changes more than villous appearance .
C. The loss of a single tumor suppressor gene such as p53 is sufficient to lead to the development of malignancy in colorectal neoplastic polyps.
D. Endoscopic polypectomy results in an increased incidence of carcinomas of the colon and rectum.
Answer: A
Juvenile polyps are hamartomas, and can cause symptoms in children such as bleeding, obstruction, and intussusception. Familial juvenile polyposis is associated with increased risk of colon carcinoma. Polyps with mixed tubular and villous appearance (tubulovillous adenomas) have an intermediate risk of malignancy; villous adenomas are the most likely to contain malignancy in each size range. While p53 and other tumor suppressor genes may be associated with the adenoma-to-carcinoma transition, it appears likely that multiple genetic defects are involved in this transformation. Alterations in p53 appear to be among the last, as changes are uncommon in adenomas but very common in carcinomas. The National Polyp Study Group (USA) demonstrated that colonoscopic polypectomy does in fact reduce the incidence of subsequent colorectal carcinomas, which supports the concept that most carcinomas begin as polyps and supports aggressive endoscopic removal.
-----------------------------------------------------------------------------------------------------------
85.Which of the following statements about familial adenomatous polyposis (FAP) is true?
A. Inherited in an autosomal-dominant manner, this genetic defect is of variable penetrance, some patients having only a few polyps whereas others develop hundreds .
B. The phenotypic expression of the disease depends only on the genotype.
C. Appropriate surgical therapy includes total abdominal colectomy with ileorectal anastomosis and ileoanal pull-through with rectal mucosectomy.
D. Panproctocolectomy with ileostomy is not appropriate therapy for this disease.
E. Pharmacologic management of this disease may be appropriate in some instances.
Answer: C
The genetic defect is of high penetrance: nearly all affected patients develop hundreds to thousands of polyps. By definition, at least 100 polyps must be present. Recent studies have shown that even patients with the identical point mutation can exhibit variability in the phenotypic expression, suggesting that environmental or other genetic factors play a significant role. The phenotypic variations concern age at onset, size of polyps, density of polyps, and extracolonic manifestations of the disease. Although panproctocolectomy with ileostomy is not well-accepted by patients because of the stoma, acceptable surgical options include panproctocolectomy with ileostomy, total colectomy with ileorectal anastomosis, and ileoanal anastomosis with rectal mucosectomy. No pharmacologic agents have been demonstrated to be efficacious in this condition, though several have been tried.
-----------------------------------------------------------------------------------------------------------------
86.Which of the following statements about the etiology of chronic ulcerative colitis is false?
A. Ulcerative colitis is 50% less frequent in nonwhite than in white populations.
B. Psychosomatic factors play a major causative role in the development of ulcerative colitis.
C. Cytokines are integrally involved in the pathogenesis of ulcerative colitis.
D. Ulcerative colitis has been identified with a greater frequency in family members of patients with confirmed inflammatory bowel disease.
E. Ulcerative colitis is two to four times more common in Jewish than in non-Jewish populations.
Answer: B
Despite intensive investigation, the specific cause of ulcerative colitis remains unknown. There appears to be a clear genetic component involved in the etiology and distribution of ulcerative colitis. It is significantly less frequent in nonwhite than in white populations and significantly more frequent among Jews than among other populations. There is a strong familial concordance by disease category: the prevalence of inflammatory bowel disease is 10% to 25% in relatives of patients with confirmed Crohn's disease or ulcerative colitis. There is considerable uncertainty about the fundamental role of infectious agents in the primary pathogenesis of ulcerative colitis. Psychological factors may play a role in exacerbations of the disease, but they are not of primary importance in its pathogenesis. Recent studies have suggested that cytokines and other immunoregulatory substances are integrally involved in the pathogenesis of inflammatory bowel disease.
--------------------------------------------------------------------------------------------------------------
87.Surgical alternatives for the treatment of ulcerative colitis include all of the following except:
A. Total Colectomy with ileal pouch–anal anastomosis.
B. Left colectomy with colorectal anastomosis.
C. Proctocolectomy with Brooke ileostomy or continent ileostomy.
D. Total colectomy with ileostomy and Hartmann closure of the rectum.
Answer: B
Ulcerative colitis is a mucosal inflammatory disease confined to the rectum and colon. It can thus be cured by total proctocolectomy. For that reason, the standard of therapy for many years was total proctocolectomy and ileostomy. In an effort to avoid permanent ileostomy a number of other alternatives have been evaluated, including subtotal colectomy with ileorectal anastomosis, proctocolectomy with continent ileostomy, and colectomy with endorectal ileal pouch–anal anastomosis. In the past, subtotal colectomy with ileorectal anastomosis was accepted as a compromise operation, with the knowledge that disease-bearing rectal tissue was retained. Because other definitive alternatives are currently available, ileorectal anastomosis is no longer appropriate for elective surgical treatment of ulcerative colitis. In an acutely ill patient or when the diagnosis is in question, subtotal colectomy with ileostomy and Hartmann closure of the rectum is the most expeditious choice and allows later restorative surgery. Partial colectomy has never been an acceptable alternative for elective operative management of ulcerative colitis; thus, left colectomy with colorectal anastomosis would not be an appropriate alternative.
----------------------------------------------------------------------------------------------------------------
88.The initial management of toxic ulcerative colitis should include:
A. Broad-spectrum antibiotics.
B. 6-Mercaptopurine.
C. Intravenous fluid and electrolyte resuscitation.
D. Opioid antidiarrheals.
E. Colonoscopic decompression.
Answer: C
Toxic colitis is a potentially life-threatening complication of chronic ulcerative colitis. Typically it manifests clinically with the onset of abdominal pain and severe diarrhea, followed by abdominal distention and generalized tenderness. Once megacolon and toxicity develop, fever, leukocytosis, pallor, tachycardia, lethargy, and shock set in. The initial treatment for toxic megacolon thus includes intravenous fluid and electrolyte resuscitation, nasogastric suction, broad-spectrum antibiotics to provide anaerobic and aerobic gram-negative coverage, and total parenteral nutrition to improve nutritional status. Large intravenous doses of corticosteroids are generally administered to treat the colitis. In addition, many patients with toxic megacolon are already receiving steroid therapy and, so, need stress doses of steroids to prevent adrenal crisis. The immunosuppressive drugs 6-mercaptopurine and azathioprine may play a role in the management of refractory ulcerative colitis; however, these drugs are not indicated in the acute management of toxicity. Cyclosporine was shown to be effective in treating acute refractory ulcerative colitis in a single controlled trial, but this has not yet been confirmed by other prospective studies, and it remains a potentially dangerous drug. Opioid antidiarrheals should be avoided since they may exacerbate the colonic dilatation and increase the possibility of perforation. Limited proctoscopy may be helpful in determining the cause of the attack, but colonoscopy may be dangerous and is contraindicated in the face of acute toxic megacolon. If toxic colitis, with or without megacolon, does not improve within 48 hours, emergency surgery is warranted.
--------------------------------------------------------------------------------------------------------
89.Which finding(s) suggest(s) the diagnosis of chronic ulcerative colitis as opposed to Crohn's colitis?
A. Endoscopic evidence of backwash ileitis.
B. Granulomas on biopsy.
C. Anal fistula.
D. Rectal sparing.
E. Cobblestone appearance on barium enema.
Answer: A
It has become increasingly important to distinguish between ulcerative colitis and Crohn's colitis, since the operative therapy for the two disease processes is quite different. Patients with ulcerative colitis are candidates for colectomy with ileoanal anastomosis, whereas Crohn's disease is a clear contraindication to this operation. Clinical findings suggestive of Crohn's disease include anal fistula or other perianal disease, though it must be kept in mind that approximately 10% of patients with ulcerative colitis may also develop perianal problems secondary to their chronic diarrhea. Endoscopic or radiographic evidence of rectal sparing is powerful evidence against a diagnosis of ulcerative colitis. However, if patients have been treated with steroid or salicylate enemas, they may have less active disease in the rectum than in the more proximal colon, a finding that could mislead the clinician about the presence or degree of rectal involvement. The deep linear ulcers that lead to a cobblestone appearance on barium enema are strongly suggestive of Crohn's disease. Typically, ulcerative colitis is confined to the rectum and colon. Frank small bowel involvement is suggestive of Crohn's disease; however, patients with active pancolitis may have secondary inflammation of the ileum, which has been called backwash ileitis. This clears after colectomy. The differential diagnosis may ultimately rely on histologic evaluation. Endoscopic biopsies are not generally useful since they only sample 3-mm. deep segments of mucosa and submucosa. Transmural inflammation and granulomas on surgical pathologic specimens are pathognomonic of Crohn's disease.
--------------------------------------------------------------------------------------------------------------
90.Axial twisting of the right colon or cecal volvulus has been shown to be associated with each of the following except:
A. A history of abdominal operation.
B. A mobile cecum.
C. An obstructing lesion in the transverse or left colon.
D. Inflammatory bowel disease.
Answer: D
Volvulus of the right colon is less common than sigmoid volvulus and may involve either an axial twist of the right colon or a cephalad fold of the cecum (cecal bascule). A mobile cecum is a prerequisite for cecal volvulus and may occur in up to one third of individuals. Cecal volvulus has also been called postoperative volvulus because of its tendency to follow abdominal surgical procedures. Obstructing lesions in the distal colon may lead to distention and torsion of the right colon in patients with abnormalities of cecal fixation.
-------------------------------------------------------------------------------------------------------
91.Sigmoid volvulus has been associated with each of the following except:
A. Chronic constipation and laxative abuse.
B. Chronic rectal proplapse.
C. Chronic traumatic paralysis.
D. Medical management of Parkinson's disease.
Answer: B
The development of sigmoid volvulus depends on the presence of a dilated, redundant sigmoid colon. This acquired redundancy may be secondary to long-term ingestion of a high-residue diet, particularly in parts of the world where the disease is common. In the United States, the most prominent association is chronic constipation and excessive reliance on laxatives or enemas. Other contributing factors include neurologic or psychiatric conditions such as Parkinson's disease, Alzheimer's disease, multiple sclerosis, traumatic paralysis, chronic schizophrenia, pseudobulbar palsy, and senility. Patients are frequently bedridden and are being managed with various neuropsychotropic drugs, both of which may alter bowel motility.
--------------------------------------------------------------------------------------------------------------
92.Which of the following recommendations for adjuvant chemotherapy of colorectal carcinoma are true?
A. Patients with Stage I or Dukes A and B1 disease should receive adjuvant treatment for 1 year with levamisole combined with 5-FU.
B. Patients with Stage III or Dukes C disease should receive adjuvant treatment for 1 year with levamisole combined with 5-FU.
C. There is no role for adjuvant therapy for colon cancer at any stage.
D. Adjuvant chemotherapy is active in colon cancer only when combined with radiotherapy.
Answer: B
Some 50% to 60% of patients with colorectal cancer have tumors that penetrate the serosa or involve the regional lymph nodes, eventually recur, and end fatally. Therefore, adjuvant therapy to improve the mortality was sought for this group of patients. 5-Fluorouracil (5-FU) is the most active drug used against colon cancer, but it achieves only a 10% to 20% response in patients with advanced disease. Levamisole is thought to be an immunomodulating agent in advanced colorectal carcinoma. Randomized controlled trials of 5-FU with levamisole, levamisole alone, and surgery in patients with Dukes B2 or C colon cancer were performed and demonstrated that levamisole plus 5-FU and levamisole improve disease-free survival for patients with Dukes B and C lesions. Subsequent analysis demonstrated that Dukes C patients receiving levamisole and 5-FU also had slightly prolonged survival.
A larger, confirmatory intergroup trial was launched that demonstrated that in patients with Dukes C carcinomas of the colon, adjuvant treatment for 1 year with levamisole combined with 5-FU reduced the risk of cancer recurrence by 41% and reduced mortality overall by 33%, but the results in patients with Dukes B2 disease was equivocal.
-------------------------------------------------------------------------------------------------------------
93.Optimal front-line treatment of squamous cell carcinoma of the rectum includes:
A. Abdominal perineal resection.
B. Low anterior resection when technically feasible.
C. Radiation therapy.
D. Chemotherapy.
E. Combined radiation and chemotherapy.
Answer: E
Combination radiation therapy and chemotherapy is now the treatment of choice for squamous cell carcinoma of the anus. The area of the primary lesion is biopsied, and the patient begins radiotherapy to the pelvis. If inguinal lymph nodes are enlarged, they are also biopsied, usually by fine-needle aspiration, and if positive, they are included in the field of radiation.
Following radiation therapy, patients receive intravenous 5-FU and mitomycin C. Patients who fail therapy have limited options, including additional chemotherapy or radiotherapy. Salvage therapy may also include abdominoperineal resection (APR), lymphadenectomy, or a diverting colostomy, depending on the nature of the recurrence.
-------------------------------------------------------------------------------------------------------
94.Which of the following statement(s) is/are true about the maintenance of continence?
A. It depends on both the internal and external sphincters as well as the puborectalis.
B. Resting pressure offers a high-pressure zone that increases resistance to the passage of stools.
C. Maximal squeeze pressure can last no more than 1 minute.
D. All true
E. All false
Answer:D
Continence depends on numerous complex and interrelated anal, rectal, pelvic floor, and colon factors. Resting pressure depends primarily on the internal sphincter and serves to increase resistance to the passage of stool. Squeeze pressure, generated by contraction of the external sphincter, increases anal canal resting pressure and helps prevent leakage when the rectal contents are presented to the proximal anal canal at inopportune times. It lasts but a minute before fatiguing. The anorectal angle produced by anterior pull of the puborectalis encircles the rectum at the level of the anorectal ring and helps to maintain continence.
---------------------------------------------------------------------------------------------------------------
95.Which of the following statement(s) about complete rectal prolapse, or procidentia is true?
A. Rectal prolapse results from intussusception of the rectum and rectosigmoid.
B. The disorder is more common in men than in women.
C. Continence nearly always is recovered after correction of the prolapse.
D. All of the above are true.
Answer: A
Rectal prolapse is believed to be the result of intussusception of the rectum and rectosigmoid. The condition predominates in women, in those who strain excessively, and in those suffering from mental disorders. Pregnancy and delivery are not implicated, as the condition can be observed in men and in nulliparous women. By the time the diagnosis is established, 50% of patients are incontinent, and continence improves in only half of the patients after surgical correction of the prolapse.
---------------------------------------------------------------------------------------------------------
96.Which of the following statements about hemorrhoids is not true?
A. Hemorrhoids are specialized “cushions” present in everyone that aid continence.
B. External hemorrhoids are covered by skin whereas internal hemorrhoids are covered by mucosa.
C. Pain is often associated with uncomplicated hemorrhoids.
D. Hemorrhoidectomy is reserved for third- and fourth-degree hemorrhoids.
Answer: C
Hemorrhoids are specialized, highly vascularized cushions in the anal canal that aid continence. The cause of hemorrhoids is unknown, but they may represent nothing more than the downward sliding of anal cushions associated with straining and irregular bowel habits. They are classified and treated according to the severity of symptoms. External hemorrhoids are covered with anoderm and are distal to the dentate line. Internal hemorrhoids are covered by the mucosal lining of the anal canal proximal to the dentate line. They can cause painless bleeding, usually in association with defecation. Uncomplicated hemorrhoids usually are not associated with pain, but fissures more often are. Hemorrhoidectomy is reserved for third-degree (bleeding with prolapse requiring manual reduction) and fourth-degree (permanently prolapsed with or without bleeding) hemorrhoids.
----------------------------------------------------------------------------------------------------------------
97.The widely accepted treatment of most localized epidermoid, cloacogenic, or transitional cell carcinoma of the anal canal is:
A. Surgical resection.
B. Chemotherapy alone.
C. Radiotherapy alone.
D. Combined chemoradiation.
Answer: D
Tumors arising in the anal canal or in the transitional zone that have squamous, basaloid, cloacogenic, or mucoepidermoid epithelium are similar in their clinical presentation and response to treatment. Combined chemoradiation (the so-called Nigro protocol) promises to preserve continence, avoid colostomy, and offer a similar survival rate. Local excision is reserved for the few very small and superficial lesions. For most lesions, chemoradiation—external-beam radiation, 5-fluorouracil, and mitomycin C—is the treatment of choice.
-----------------------------------------------------------------------------------------------------------
98.Which statement(s) is true about hidradenitis suppurativa?
A. It is a disease of the apocrine sweat glands.
B. It causes multiple perianal and perineal sinuses that drain watery pus.
C. The sinuses do not communicate with the dentate line.
D. The treatment is surgical.
E. All of the above.
Answer: E
Hidradenitis suppurativa is an inflammatory process of the sweat glands characterized by abscess and sinus formation. The disease may involve other areas where apocrine glands are present, such as the axilla, mammary, inguinal, and genital regions. The affected areas have a blotchy, purplish appearance with numerous sinuses draining watery pus. The condition must be differentiated from cryptoglandular fistulas, which communicate with the dentate line, and Crohn's disease, which may track to the anorectum proximal to the dentate line. Treatment consists of unroofing sinuses for limited disease and wide local excision for more advanced disease.
-----------------------------------------------------------------------------------------------------------------
99.Which of the following statements regarding the vasculature of the colon and rectum is false?
A.The middle colic artery is a branch of the superior mesenteric artery
B.The inferior mesenteric artery supplies the descending and sigmoid segments of the colon
C.An complete anastomotic arcade paralleling the colon wall is present in only 15 to 20& of individuals
D.The middle colic artery is a branch of the inferior mesenteric artery
Answer: D
Two major arterial systems supply the colon. The right colon is predominantly supplied by the superior mesenteric artery. The major branches of this artery that perfuse the right colon include the ileocolic branch, which supplies the ileocecal junction; the right colic, which supplies the ascending colon; and the middle colic artery, which supplies the hepatic flexure and the transverse colon to its midpoint. The left colon is predominantly supplied by the inferior mesenteric artery, which derives its origin from the abdominal aorta. The distal transverse colon and the descending colon obtain their blood supply from the left colic branch of the inferior mesenteric artery, while the sigmoid colon obtains its blood supply from sigmoidal branches. The colic arteries bifurcate and form vascular arcades so that the resultant marginal Drummond artery forms an anastomosis between the superior mesenteric artery and the inferior mesenteric artery. However, considerable anatomic variation exists with respect to this arterial arcade, and a complete anastomosis is present in only 15% to 20% of people.
---------------------------------------------------------------------------------------------------------
100.Which of the following agents have been proposed as sensory neurotransmitters for the colon?
A.Acetylcholine
B.Substance P& Calcitonin gene-related peptide
C.Bradykinin
D.Somatostatin
Answer: B
Sensory neurons within the wall of the colon perceive mechanical and chemical stimuli from the luminal contents. Their axons project both to motor neurons as well as to prevertebral ganglia and higher neural centers. Mediators of such sensory input appear to be substance P and calcitonin-gene related peptide. The role of sensory neurons in transmitting information remains uncertain, but since they have been shown to synapse on the excitatory and inhibitory motor neurons, they probably play an important role in modulating spontaneous contractions.
101.Blood transfusion can cause all of the following except:
a.hypothermia
b.hyperthermia
c.metabolic acidosis
d.metabolic alkalosis
e.hyperkalemia
f.hypokalemia
g.hypocalcemia
h.hypercalcemia
answer H
---------------------------------------END------------------------------------------
With my best wishes
Dr .Jaber AlFaifi
jaberayf@
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.