Toxicology USMLE Step 1 Practice Question
A 17-year-old girl presents to the emergency department after ingesting an entire bottle of aspirin two hours ago. She is tachypneic (RR 28/min), tachycardic (HR 118/min), and febrile (38.2°C). She complains of nausea, vomiting, and tinnitus. Blood pressure is 118/76 mmHg. Physical examination reveals no altered mental status. Serum salicylate level is 65 mg/dL. Arterial blood gas is most likely to show which acid-base pattern early in this poisoning?
Answer choices
- AMetabolic alkalosis followed by respiratory acidosis
- BRespiratory acidosis followed by metabolic alkalosis
- CNormal acid base status with isolated hypernatremia
- DPure non anion gap metabolic acidosis only
- ERespiratory alkalosis followed by an anion gap metabolic acidosisCorrect answer
- FPure respiratory alkalosis with normal anion gap
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.