ABEM Toxicology, Environmental & Infectious Diseases 3

Question 1

A child ingests iron tablets and presents 6 hours later with vomiting, abdominal pain, and bloody diarrhea. Which laboratory finding best indicates systemic iron toxicity?

Accepted Answer

Anion gap metabolic acidosis

Answer

An anion gap metabolic acidosis reflects mitochondrial dysfunction from free radical damage and is a marker of systemic iron toxicity requiring deferoxamine.

Question 2

A patient develops diffuse muscle pain, dark urine, and AKI after a severe rattlesnake envenomation. Which complication is most directly responsible for the renal injury?

Accepted Answer

Myoglobinuria from venom-induced rhabdomyolysis

Answer

Crotalid venom causes myonecrosis and rhabdomyolysis; the resulting myoglobinuria precipitates in renal tubules and causes acute tubular necrosis.

Question 3

Which of the following is the MOST appropriate management of severe hypothermia (core temp 25°C) with ventricular fibrillation refractory to three defibrillation attempts?

Accepted Answer

Continue CPR and withhold further shocks until rewarmed to ≥30°C

Answer

In severe hypothermia, pharmacologic and electrical therapies are largely ineffective below 30°C; CPR should be maintained and rewarming prioritized before repeating defibrillation.

Question 4

A patient with HIV and CD4 count of 60/µL presents with headache, fever, and altered mentation. India ink stain of the CSF is positive. What is the first-line induction therapy?

Accepted Answer

Amphotericin B deoxycholate + flucytosine

Answer

Cryptococcal meningitis induction therapy requires amphotericin B plus flucytosine for at least 2 weeks to achieve fungal clearance before consolidation with fluconazole.

Question 5

After a house fire, a victim presents with confusion, cherry-red skin, and carboxyhemoglobin of 28%. What is the half-life of COHb with 100% normobaric oxygen?

Accepted Answer

~60–90 minutes

Answer

100% normobaric oxygen reduces the carboxyhemoglobin half-life from ~5 hours on room air to approximately 60–90 minutes.

(ABEM) American Board of Emergency Medicine Practice Test

(ABEM) American Board of Emergency Medicine Practice Test

ABEM Toxicology, Environmental & Infectious Diseases 3