- FENa < 1%: Prerenal AKI (not reliable if diuretics used)
- FEUrea < 35%: Better for patients on diuretics
- BUN:Cr > 20: Suggests prerenal state
- FENa can be <1% also in contrast nephropathy, myoglobinuria, acute GN
- Spot urine PCR (protein:creatinine) ≥ 0.3 g/g: Significant proteinuria
- ≥ 3.5 g/day: Nephrotic range
- Microalbuminuria (30–300 mg/day): Early diabetic nephropathy
- ACE-i/ARBs reduce proteinuria independently of blood pressure lowering
- ↑ Cr ≥ 0.3 mg/dL in 48h, OR
- ↑ Cr ≥ 1.5. baseline within 7 days, OR
- UO < 0.5 mL/kg/hr for ≥ 6 hours
- Muddy brown casts: ATN (ischemic or nephrotoxic
- RBC casts: Glomerulonephritis (pathognomonic)
- WBC casts: AIN or pyelonephritis
- Granular casts: Non-specific; ATN, CKD
- Avoid: NSAIDs, metformin (eGFR <30), gadolinium (NSF risk), SGLT2i (ineffective <25 mL/min)
- Reduce: Renally-cleared antibiotics (aminoglycosides, vancomycin, beta-lactams, gabapentin)
- Contrast: Hold with eGFR <30 or AKI; ensure adequate hydration pre/post procedure
- Digoxin toxicity risk ↑ with ↓ GFR (narrow therapeutic window)
- CKD is an independent CV risk factor; mortality from CV disease exceeds ESRD
- BP target: <130/80 mmHg (KDIGO 2021); ACE-i/ARB first-line if proteinuria present
- SGLT2 inhibitors: Proven cardiorenal protection in CKD (CREDENCE, DAPA-CKD trials)
- Anemia: Target Hgb 10–11.5 g/dL with ESA therapy; replete iron concurrently
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Test your knowledge with the Bean Bowl on the Equilibrium Architects home page. A cumulation of board style questions from all sections.