Acute Kidney Injury USMLE Step 1 Practice Question
A 67-year-old man with hypertension and type 2 diabetes presents with acute onset oliguria after undergoing coronary angiography for unstable angina. Serum creatinine increased from 1.2 to 3.8 mg/dL within 48 hours. Urinalysis shows muddy brown casts and minimal proteinuria. Urine osmolality is 350 mOsm/kg and urine sodium is 65 mEq/L. Which of the following is the most likely diagnosis?
Answer choices
- APrerenal acute kidney injury from dehydration
- BAcute tubular necrosis from contrast-induced nephropathyCorrect answer
- CAcute glomerulonephritis from lupus nephritis
- DPostrenal acute kidney injury from ureteral obstruction
- EAcute interstitial nephritis from medication exposure
- FThrombotic microangiopathy from disseminated intravascular coagulation
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