Toxicology USMLE Step 1 Practice Question
A 19-year-old college student is brought to the emergency department after intentionally ingesting a bottle of aspirin tablets. He presents with tinnitus, nausea, and tachypnea (RR 28/min). Vital signs show BP 138/85 mm Hg, HR 102/min, temp 38.2°C, SpO2 98% on room air. Arterial blood gas reveals pH 7.47, PaCO2 24 mm Hg, HCO3- 17 mEq/L, and serum salicylate level 89 mg/dL. No altered mental status is currently noted. Which acid-base disturbance best explains these findings?
Answer choices
- ARespiratory acidosis only
- BRespiratory alkalosis with anion gap metabolic acidosisCorrect answer
- CNonanion gap metabolic acidosis only
- DMetabolic alkalosis only
- ERespiratory acidosis with metabolic alkalosis
- FMetabolic acidosis only
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.