Clinical management scenarios for acute kidney injury workup, chronic kidney disease staging, and dialysis decisions tested on USMLE Step 2 CK.
40 cards · basic cards · AI-written, checked twice. Edit anything.
- What absolute serum creatinine rise, within what time frame, meets KDIGO criteria for AKI?
- An increase of at least 0.3 mg/dL within 48 hours
- What relative serum creatinine rise, within what time frame, meets KDIGO criteria for AKI?
- At least 1.5 times the baseline value within 7 days
- What urine output threshold meets KDIGO criteria for AKI?
- Less than 0.5 mL/kg/hr for at least 6 hours
- A FENa below what value suggests prerenal azotemia?
- Less than 1 percent
- A FENa above what value suggests intrinsic AKI such as acute tubular necrosis?
- Greater than 2 percent
- Why is FENa unreliable for classifying AKI in a patient on diuretics, and what index should be used instead?
- Diuretics force sodium excretion regardless of cause, so FEUrea should be used instead
- What urine microscopy finding is classic for acute tubular necrosis?
- Muddy brown granular casts
- What urine microscopy finding suggests acute interstitial nephritis?
- White blood cell casts
- What urine microscopy finding suggests glomerulonephritis as the cause of AKI?
- Red blood cell casts (dysmorphic RBCs)
- A BUN to creatinine ratio greater than what value suggests prerenal azotemia?
- Greater than 20 to 1
- What is the most common cause of hospital-acquired AKI?
- Acute tubular necrosis (ischemic or nephrotoxic)
- What two common drug classes cause AKI by altering glomerular hemodynamics rather than direct toxicity?
- NSAIDs and ACE inhibitors/ARBs
- By what mechanism do NSAIDs cause AKI?
- They inhibit prostaglandins that dilate the afferent arteriole, lowering GFR
- By what mechanism do ACE inhibitors precipitate AKI in a patient with bilateral renal artery stenosis?
- Loss of angiotensin II-mediated efferent arteriolar constriction causes GFR to drop
- What is the classic clinical triad of drug-induced acute interstitial nephritis?
- Fever, rash, and eosinophilia