Emergency Medicine Q & A, 2009, Pg

Emergency Medicine Q & A, 2009, Pg


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technetium-tagged red blood cell scan.
c. Resuscitate with crystalloid only, consult diagnostic and therapeutic endoscopist for
esophagogastroduodenoscopy (EGD).
d. Resuscitate with crystalloid and blood, consult general surgeon for laparotomy.
e. Resuscitate with crystalloid only, obtain surgical consultation.
The answer is b. Blood per rectum can signal either upper or lower GI bleeding. Placement of a nasogastric tube
with lavage can rule out bleeding proximal to the pylorus. If blood is found, then EGD is the diagnostic and
therapeutic maneuver of choice. If no blood is found (but bile is aspirated), then a lower GI source of bleeding is
more likely. Angiography sometimes can detect the site of bleeding, but requires a relatively brisk bleeding rate
(0.5\u20132.0 mL/min) to be diagnostic. Technetium-labeled red cell scintigraphy is even more sensitive than
angiography and can localize the site of bleeding at a rate of 0.1 mL/min. The hemoglobin is critically low, and
blood transfusion should be started along with crystalloid infusion. CT scan has only a minimal role in the
management of GI bleeding. Laparotomy is not indicated until the bleeding is localized by other tests to the upper
or lower GI system.
... CHAPTER 2 Abdominal and Gastrointestinal Emergencies 29
11. A 54-year-old man with long history of alcohol abuse and prior history of pancreatitis complains of severe
upper abdominal pain and numerous episodes of nonbloody, nonbilious vomiting after a weekend binge of
drinking. His serum amylase level is within normal range, but you still suspect acute pancreatitis, knowing
that amylase may be falsely depressed in a patient with concomitant:
a. Hypercholesterolemia.
b. Hypertriglyceridemia.
c. Helicobacter pylori infection.
d. Hypocalcemia.
e. Occult gastrointestinal bleeding.
The answer is b. While serum amylase is a reasonable screening tool for acute pancreatitis, it is not perfect. If you
can exclude intestinal perforation or infarction from the differential (both of which cause a rise in amylase), then a
level >300 U/dL is present in 85% of patients within the \ufb01rst 24 hours of symptoms. Reasons for incorrect normal
values include extensive pancreatic necrosis, infarction, and pseudocyst formation. Both serum amylase and serum
lipase can be falsely low in patients with hypertriglyceridemia. False lows are also reported in patients with chronic
pancreatitis.
12. A 50-year-old man complains of abdominal pain and a 1-week history of black bowel movements, weakness,
nausea, and dark colored urine. He reports heavy alcohol consumption. His gait is ataxic. His temperature is
37.9\u25e6C, heart rate 70/min, respiratory rate 18/min, and blood pressure 140/60 mmHg. He is disoriented
and has a tender enlarged liver, guaiac-positive stool, and mild ascites. Laboratory test results: WBC, normal;
PT and INR, mildly prolonged; AST, 3 times normal; total bilirubin, 2.0; alkaline phosphatase, moderately
elevated. Immediate management should include:
a. Rectal lactulose.
b. Abdominal CT with contrast.
c. Percutaneous liver biopsy.
d. Diagnostic paracentesis.
e. Bedside ultrasound.
The answer is d. Alcoholic hepatitis is often associated with additional complicating disease: meningitis,
pneumonia, subdural hematomas, peritonitis, and GI bleeding. Hepatic encephalopathy may account for
neuropsychiatric symptoms. Treatment is supportive, and unless the disease is clearly mild, hospital admission is
justi\ufb01ed. Blood cultures should be ordered to evaluate for sepsis. A paracentesis is needed to evaluate for
spontaneous bacterial peritonitis. If indicated, a liver biopsy may be performed on an elective basis, but certainly
not before reversal of the abnormal coagulation status.
30 Emergency Medicine Q & A: Pearls of Wisdom ...
13. A 50-year-old man complains of abdominal pain. He recently underwent open cholecystectomy and
exploration of the common bile duct for gallstone pancreatitis. He is afebrile and has epigastric tenderness.
You palpate a vague mass in the right upper quadrant. Bile drains from the T-tube. You should now order:
a. HIDA scan.
b. Full obstruction series.
c. Abdominal CT scan with oral and intravenous contrast.
d. Chest radiograph to rule out free air.
e. Upper GI series with barium.
The answer is c. CT scan in a patient with suspected pancreatitis helps to rule out other causes of abdominal pain
and evaluates potential peripancreatic complications such as hemorrhage, pseudocyst, abscess, or vascular
abnormalities. It is also quite accurate at determining the amount of pancreatic necrosis. The Atlanta International
Symposium recommends CT in patients with (1) an uncertain diagnosis; (2) severe clinical pancreatitis, abdominal
distention, tenderness, temperature higher than 102\u25e6F, and leukocytosis; (3) a Ranson score of more than 3 or
APACHE score of more than 8; (4) no improvement within 72 hours; and (5) acute deterioration. The main
indication for obtaining a CT scan in the emergency department is to exclude other diagnoses; however, if the
patient is signi\ufb01cantly ill and can tolerate the procedure, early CT may help determine whether complications are
already present.
14. The most sensitive and speci\ufb01c test to con\ufb01rm the diagnosis of acute cholecystitis is:
a. Oral cholecystogram.
b. HIDA radioisotope scan.
c. Ultrasound.
d. Plain \ufb01lm of the abdomen.
e. The triad of fever, elevated bilirubin, and elevated alkaline phosphatase.
The answer is b. Ultrasonography has an unadjusted 94% sensitivity and 78% speci\ufb01city for the diagnosis of acute
cholecystitis. The 50% sensitivity of CT scanning is insuf\ufb01cient for it to be used in place of ultrasonography.
Technetium-iminoacetic acid analogue-based radioisotope scintigraphy (HIDA) has 97% sensitivity and 90%
speci\ufb01city. Within 1 hour of injection, a normal patient will have a clearly outlined gallbladder and cystic duct.
Failure to demonstrate the gallbladder within this time frame is consistent with cystic duct obstruction.
15. A 39-year-old woman complains dif\ufb01culty swallowing, predominantly with liquids, and regurgitation of
foul-tasting food. She had an esophagram a few days ago, and you obtain the results, which show a \ufb02accid,
dilated esophagus with a sharply tapered narrowing at the gastroesophageal junction. She has:
a. Esophageal colic.
b. Esophageal malignancy.
c. Re\ufb02ux esophagitis.
d. Scleroderma.
e. Achalasia.
The answer is e. Achalasia is a disorder of esophageal motility and incomplete relaxation of the lower esophageal
sphincter (beaking of LES). In contrast to mechanical narrowing, the dysphagia is often temperature-dependent
and improves with warm food. Radiologically, it may be confused with malignancy. Re\ufb02ux esophagitis and peptic
stricture do not result in a signi\ufb01cantly dilated esophagus. Scleroderma causes a rigid, aperistaltic esophagus; the
LES is not beaked.
... CHAPTER 2 Abdominal and Gastrointestinal Emergencies 31
16. A 37-year-old woman with extensive past medical history now has acute cholecystitis. You suspect
cholesterol gallstones because of her past history of:
a. Hypertriglyceridemia.
b. Hypercholesterolemia.
c. G6PD de\ufb01ciency with recent inadvertent use of sulfa-containing antibiotic.
d. Sickle cell trait.
e. Surgical resection of the ileum.
The answer is e. Obesity, clo\ufb01brate therapy, age, and oral contraceptive use contribute to the formation of
cholesterol gallstones, by increasing biliary cholesterol excretion. Ileal resection leads to malabsorption of bile salts,
depletion of bile acid pool, and an inability to micellize cholesterol, resulting in an increased risk of gallstone
formation. There is no correlation between serum cholesterol level and biliary cholesterol stone formation.
Cholesterol gallstones can also form during gallbladder hypomotility, such as occurs with parenteral nutrition,
fasting, or pregnancy. While hemoglobinopathies, such as sickle