Acid-Base Disorders USMLE Step 1 Practice Question
A 17-year-old girl is brought to the emergency department because of nausea, vomiting, and tinnitus after ingesting an unknown number of tablets during an argument with her parents. Arterial blood gas shows pH 7.42, PaCO2 24 mm Hg, and HCO3− 15 mEq/L. Which of the following best describes her acid-base status?
Answer choices
- AMixed respiratory alkalosis and metabolic acidosisCorrect answer
- BMixed respiratory acidosis and metabolic alkalosis
- CPure respiratory alkalosis
- DPure nonanion gap metabolic acidosis
- EPure anion gap metabolic acidosis
- FCompensatory respiratory alkalosis with primary metabolic acidosis
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