Acute Kidney Injury USMLE Step 1 Practice Question
A 68-year-old man with a 10-year history of type 2 diabetes mellitus and hypertension presents for routine follow-up. His baseline serum creatinine is 1.8 mg/dL (eGFR 38 mL/min/1.73mĀ²), and urinalysis shows 2+ proteinuria. He is started on lisinopril 10 mg daily for diabetic nephropathy. Two weeks later, he reports mild fatigue and dyspnea on exertion. Laboratory studies show: serum creatinine 2.6 mg/dL, BUN 48 mg/dL, potassium 5.8 mEq/L, bicarbonate 20 mEq/L, and urine sodium 15 mEq/L. Urinalysis remains unchanged with no hematuria or casts. Blood pressure is 138/82 mmHg. Which of the following is the most appropriate next step in management?
Answer choices
- AContinue lisinopril and initiate loop diuretic therapy to improve renal perfusion
- BObtain urgent renal artery duplex ultrasound to evaluate for renal artery stenosis
- CDiscontinue lisinopril, initiate hemodialysis, and administer insulin for hyperglycemia
- DDiscontinue lisinopril, check serum creatinine in 1-2 weeks, and address hyperkalemiaCorrect answer
- EIncrease lisinopril dose to 20 mg daily and add amlodipine for improved blood pressure control
- FContinue lisinopril with close monitoring; the creatinine rise is expected and reversible
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