Acid-Base Disorders USMLE Step 1 Practice Question
A 48-year-old man with chronic alcoholism presents to the emergency department with acute confusion and slurred speech. Vital signs show BP 128/82 mmHg, HR 102 bpm, RR 18/min, temp 36.8°C, SpO2 98% on room air. Labs reveal Na+ 140 mEq/L, Cl− 88 mEq/L, HCO3− 34 mEq/L, and elevated serum beta-hydroxybutyrate. Blood glucose is normal. Which acid-base disorder best describes his status?
Answer choices
- APure anion gap metabolic acidosis
- BMixed respiratory acidosis and metabolic alkalosis
- CPure metabolic alkalosis
- DMixed anion gap metabolic acidosis and metabolic alkalosisCorrect answer
- ENonanion gap metabolic acidosis
- FRespiratory alkalosis with concurrent metabolic acidosis
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