Acid-Base Disorders USMLE Step 1 Practice Question
A 22-year-old woman with type 1 diabetes is brought to the emergency department because of abdominal pain and progressive lethargy for 1 day. She has had polyuria and polydipsia for several days after running out of insulin. Temperature is 37.1 C (98.8 F), blood pressure is 96/58 mm Hg, pulse is 118/min, and respirations are deep and rapid. Mucous membranes are dry. Laboratory studies show Na+ 132 mEq/L, Cl− 96 mEq/L, HCO3− 10 mEq/L, glucose 540 mg/dL, and positive serum ketones. Which of the following acid-base disturbances is most likely present?
Answer choices
- AMetabolic alkalosis
- BRespiratory alkalosis
- CAnion gap metabolic acidosisCorrect answer
- DChronic respiratory acidosis
- ENonanion gap metabolic acidosis
- FHyperchloremic non-anion gap metabolic acidosis
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