Gastrointestinal

Question 1

What is the mechanism of action of simethicone?

Answer 1

It decreases the surface tension of gas bubbles, thereby dispersing and preventing gas pockets in the GI system (Lexicomp).

Question 2

In diagnosing gallstone ileus, what is Rigler’s triad?

Answer 2

pneumobilia - air in the bile ducts
evidence of small bowel obstruction
ectopic gallstone (gallstone outside of the gallbladder)

See osmosis video at https://en.wikipedia.org/wiki/Gallstone_ileus

Question 3

How is a HIDA scan done?

Answer 3

Technetium labeled hepatic iminodiacetic acid (HIDA) is injected intravenously and is then taken up selectively by hepatocytes and excreted into bile. If the cystic duct is patent, the tracer will enter the gallbladder, leading to its visualization without the need for concentration. The HIDA scan is also useful for demonstrating patency of the common bile duct and ampulla. Normally, visualization of contrast within the common bile duct, gallbladder, and small bowel occurs within 30 to 60 min. The test is positive if the gallbladder does not visualize. This occurs because of cystic duct obstruction, usually from edema associated with acute cholecystitis or an obstructing stone.

[From UpToDate, “Acute cholecystitis: Pathogenesis, clinical features, and diagnosis”]

Question 4

What classification of drug is metoclopramide (Reglan)?

Answer 4

Centrally acting dopamine receptor antagonist

[From: Goodman and Gilman’s]

Question 5

What serious adverse effect can occur with administration of fluconazole?

Answer 5

Hepatitis/hepatotoxicity

Question 6

The mechanism of action of ursodeoxycholic acid (ursodiol) is to decrease the _______ content of bile and bile stones by reducing the secretion of cholesterol from the liver and the fractional reabsorption of cholesterol by the _______. Mechanism of action in primary biliary cirrhosis is not clearly defined.
This drug undergoes extensive _______ _______.

Answer 6

cholesterol
intestines
enterohepatic recycling

[From Lexicomp via UpToDate]

Question 7

What pharmacologic agent is ursodiol classified as?

Answer 7

gallstone dissolution agent

[From Lexicomp via UpToDate]

Question 8

How is hepatic encephalopathy graded?

Answer 8

The severity of hepatic encephalopathy is graded based on the clinical manifestations:

• Minimal: Abnormal results on psychometric or neurophysiological testing without clinical manifestations.
• Grade I: Changes in behavior, mild confusion, slurred speech, disordered sleep.
• Grade II: Lethargy, moderate confusion
• Grade III: Marked confusion (stupor), incoherent speech, sleeping but arousable
• Grade IV: Coma, unresponsive to pain

[Retrieved from UpToDate, “Hepatic encephalopathy in adults: Clinical manifestations and diagnosis”]

Question 9

When is pentoxifylline indicated?

Answer 9

Alcoholic hepatitis (severe) Maddrey Discriminant Function [MDF] score ≥32, especially when corticosteroids are contraindicated.

Question 10

Pancreatitis has been attributed to __________, with one case report showing increased severity after rechallenge.

Answer 10

simvastatin

[Clinical Key, Meyler’s Side Effects of Drugs: Simvastatin]

Question 11

The triad of bleeding from angiodysplasia, aortic stenosis (AS), and acquired von Willebrand syndrome has been called…

Answer 11

…Heyde syndrome.

[from UpToDate, “Angiodysplasia of the gastrointestinal tract”]

Question 12

What is the cause of severe hypocalcemia in patient’s with pancreatitis?

Answer 12

Hypocalcemia in patients with acute pancreatitis is associated with precipitation of calcium soaps in the abdominal cavity.

[From UpToDate: “Etiology of hypocalcemia in adults”]

Question 13

In a study titled “Intraperitoneal free fatty acids induce severe hypocalcemia in rats: a model for the hypocalcemia of pancreatitis”, indirect evidence suggests the cause of hypocalcemia in pancreatitis. The saturated fats induced little or no hypocalcemia, but the two ___________ free fatty acids (oleate and linoleate) caused dramatic hypocalcemia in the treated vs control rats.

Answer 13

unsaturated

[From UpToDate, Medline Abstract for Reference of ‘Etiology of hypocalcemia in adults’]

Question 14

What is Boerhaave syndrome?

Answer 14

Effort rupture of the esophagus, often caused by severe straining or vomiting.
High morbidity and mortality, and fatal in the absence of therapy.

[from UpToDate]

Question 15

In cirrhosis, all procoagulant factors are decreased except for factor ___ and ___ __________ factor, which are actually increased because of reduced hepatic clearance. Also, the body’s natural anticoagulants, ________ _ and _, are both reduced, which increases the likelihood of thrombotic events.
As a result of these hemostatic imbalances, patients with cirrhosis often present with an elevated international normalized ratio (INR) and a prolonged PT.
Health care providers often attempt to reverse the elevated INR by giving patients vitamin K supplementation; however, the practice of vitamin K supplementation in cirrhotic patients is not well defined, and its true value appears questionable.

Answer 15

VIII and von Willebrand
proteins C and S

[From: “Routine Use of Vitamin K in the Treatment of Cirrhosis-Related Coagulopathy: Is it A-O-K? Maybe Not, We Say”]

Question 16

One important aspect of the hemostatic abnormalities in cirrhosis includes modifications in both the procoagulant and anticoagulant protein sides of the cascade. On the anticoagulant side, there is a reduction in the synthesis of preactivated factors II, V, VII, IX, X, and XI. Conversely, on the procoagulant side, there is a decrease in ____________ ___ and proteins C and S, with an increase in factor VIII and von Willebrand factor.

In cirrhosis, the underlying reduction in viable hepatocytes results in a relatively reduced production of these pre-vitamin K activated coagulation factors. As the liver is almost entirely responsible for the synthesis of all the coagulation factor precursors, patients with cirrhosis have decreased circulating concentrations of all the inactivated coagulation factors, except factor VIII. Factor VIII is also produced ______________ in endothelial cells. In cirrhosis, factor VIII levels are typically elevated because, like all other activated clotting proteins, factor VIII also requires hepatic clearance. With cirrhosis, the liver clears less of the activated von Willebrand factor and factor VIII, resulting in the further elevation of these proteins in relation to the other coagulation factors. Proteins C and S are also synthesized in the liver and circulate in decreased concentrations in cirrhosis.

Answer 16

antithrombin III

extrahepatically

[From: “Routine Use of Vitamin K in the Treatment of Cirrhosis-Related Coagulopathy: Is it A-O-K? Maybe Not, We Say”]

Question 17

What is the indication for a POEM procedure?

Answer 17

achalasia; may be done in setting of failed prior treatments

Question 18

What does the clinician need to know about icteric blood specimens?

Excess bilirubin affects many different types of assays, either due to spectrophotometric interference or chemical oxidation of the analyte by bilirubin. As with the case for hemolysis and lipemia, the user should follow the _______ __ ___ _________ to determine the suitability of icteric samples for analysis.

Answer 18

recommendations of the manufacturer