Emergency Medicine Written Board Exam Sample Questions
Book 2 - 2006
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QUESTION

19.        A 3-year-old boy is brought in by his parents after he was found playing with his grandmother’s medicine bottles 30 minutes ago. The bottles did not have child-proof tops and one was opened. Glyburide tablets were scattered about, and as many as five tablets are missing. A tablet was found in his diaper and another extracted from his mouth. 

He appears normal and is euglycemic by finger-stick blood glucose measurement. 

Which of the following is TRUE?

A) After glyburide exposure, hypoglycemic patients may be safely discharged after parenteral dextrose and a 6-hour period of euglycemia
B) All pediatric patients with possible exposure to hypoglycemic agents must be admitted to the hospital
C) All sulfonylurea medications have a similar time to peak effect, however they may differ in duration of action
D) Glyburide, like other biguanide medications, induces hypoglycemia by decreasing hepatic glycogenolysis
E) Octreotide’s use as an antidote is limited by side effects

ANSWER

19.             C          All sulfonylurea medications have a similar time to peak effect,
                              however they may differ in duration of action

Glyburide (Micronase, DiaBeta, Glynase) is a member of the sulfonylurea class of hypoglycemic agents used for the treatment of type II diabetes. Sulfonylureas decrease blood glucose by direct action at pancreatic beta-islet cells that promotes insulin release. In overdose, these agents can induce significant hypoglycemia and may be especially dangerous in the pediatric population where even a small (1-2 tablets) exposure may cause significant hypoglycemia. All sulfonylureas have a similar time to peak effect of around 4-6 hours; however they may differ in their duration of action. This is important in the management of potentially toxic exposures, as all are expected to develop symptoms within eight hours of ingestion. In clinical studies of pediatric sulfonylurea ingestion, in fact, all patients who become symptomatic do so within 8 hours except in cases where parenteral dextrose has been given. This delayed onset of toxicity most likely represents masking of earlier onset hypoglycemia by IV dextrose rather than a true delay in the effects of the sulfonylureas. Therefore in the case of asymptomatic pediatric exposure to sulfonylurea, the patient may be observed with serial blood glucose determinations and, provided no hypoglycemia develops, discharged after eight hours. All hypoglycemic patients warrant hospital admission.

The first line of therapy in the hospital is IV dextrose. Initially bolus-dose dextrose should be given followed by dextrose infusion in cases where hypoglycemia persists. Octreotide, a somatostatin analog, counters the effect of sulfonylureas by blocking insulin release at the pancreatic beta-islet cells. It has emerged as a logical antidote for sulfonylurea overdose. In short-term dosing octreotide has no side effects. The optimal dosing guidelines for octreotide have not been established. The recommended dose for adults is 50-100 mcg (pediatric dose: 4-5 mcg/kg/day divided every 6 hours) given IV or SC every 12 hours. Octreotide should be administered at the onset of hypoglycemia with IV dextrose. After octreotide is given, many patients will not require any further dextrose supplementation. Biguanide oral anti-hyperglycemic agents are a distinct class from the sulfonylureas and include metformin and phenformin. They act primarily by limiting hepatic glucose production and decreasing insulin resistance at peripheral insulin receptors. When taken alone, even in overdose, they are not expected to induce severe hypoglycemia.

1. Harrigan RA, Nathan MS, Beattie P. Oral agents for the treatment of type 2 diabetes mellitus: pharmacology, toxicity, and treatment. Ann Emerg Med 2001;38(1):68-78. (2004 LLSA article)

161.      A 20-year-old man complains of wrist pain after a high-speed motor vehicle crash. His right wrist is swollen and tender with a minimal deformity to the wrist. The neurovascular exam of his wrist is normal. A radiograph is obtained and shown below.

Which of the following statements is LEAST accurate?

A) Emergent orthopedic consultation is required
B) The injury is a result of forceful dorsiflexion and impact on an outstretched hand
C) The injury is part of a continuous spectrum of ligamentous disruption
D) The median nerve may be compromised
E) The scapholunate and triquetrolunate joint space is increased on PA view

ANSWER

161.           E          The scapholunate and triquetrolunate joint space is increased                                on PA view

The radiograph depicts a lunate dislocation. Perilunate and lunate dislocations represent midcarpal ligament disruption, usually involving the scapholunate ligament. These dislocations may occur with or without an associated carpal bone fracture. The dislocations usually occur as a result of very forceful dorsiflexion on an outstretched hand, as occurs with a fall from a height or a motor vehicle accident. During the injury, the ligaments and carpal bones around the lunate are stripped away, and the capitate is displaced posterior to the lunate resulting in a perilunate dislocation. If a lunate dislocation occurs, the capitate rebounds back to push the lunate off of the radius into the palm. A gross deformity is usually absent, and diagnosis depends on proper interpretation of the radiographs. In a perilunate dislocation on the lateral wrist radiograph, the capitate is displaced posteriorly to the lunate, and the lunate maintains contact with the radius. On the PA view, the scapholunate and triquetrolunate joint spaces may be increased due to torn ligaments. In a lunate dislocation, the lunate may look like a “piece of pie” on the PA view, and this sign is pathognomonic for a lunate dislocation. On a lateral view, the lunate is pushed off of the radius and resembles a spilled tea-cup, and this is known as the “tea-cup sign”. Perilunate and lunate dislocations require emergent orthopedic consultation. Open, unstable or irreducible dislocations require open reduction and fixation. Complications of a lunate dislocation occasionally include median nerve compression due to the volar dislocation into the carpal tunnel.

1. Tintinalli. Emergency Medicine: A Comprehensive Study Guide. 6th Ed. 2003:1678.

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