Acid-Base Disorders USMLE Step 1 Practice Question
A 39-year-old woman with resistant hypertension (BP 168/102 mmHg) presents with frequent muscle cramps and polyuria. Vital signs show HR 88/min, RR 16/min, temperature 37.2°C. Laboratory studies reveal potassium 2.9 mEq/L, bicarbonate 33 mEq/L, and plasma renin activity suppressed at 0.3 ng/mL/hr. Serum chloride is 94 mEq/L. She denies vomiting or diarrhea. Which acid-base disorder is most likely present?
Answer choices
- ARespiratory acidosis
- BRespiratory alkalosis
- CNonanion gap metabolic acidosis
- DMetabolic alkalosisCorrect answer
- EAnion gap metabolic acidosis
- FMixed metabolic acidosis and respiratory alkalosis
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