← Diagnosis and Management Guides
Acute Kidney Injury
Key considerations: Obstructive uropathy, Rhabdomyolysis, TTP/HUS
Cannot miss
- Obstructive uropathy
- Rhabdomyolysis
- TTP/HUS
- Bilateral renal artery thrombosis
Likely diagnoses
- Prerenal AKI (most common)
- ATN
- Obstructive uropathy
- AIN
Red flags
- Anuria
- Hyperkalemia
- Severe metabolic acidosis
- Volume overload with pulmonary edema
Workup
- history: Volume status, nephrotoxin exposure, urinary symptoms; exam: Volume status assessment, bladder distension; labs: BMP, CBC, urinalysis with microscopy, FENa, urine Na; CK if rhabdomyolysis suspected; imaging: Renal ultrasound to rule out obstruction; bedside: Bladder scan, IVC assessment
Management
- immediate: Treat hyperkalemia if present; Foley catheter if obstruction suspected; IV fluids for prerenal AKI; general: Stop nephrotoxins (NSAIDs, ACEi/ARB, contrast); Match ins and outs; Renal dose adjust all medications
Disposition
- admit: Significant electrolyte abnormalities, need for dialysis, uncertain etiology; discharge: Mild prerenal AKI responding to fluids with close follow-up; consults: Nephrology if dialysis indicated or etiology unclear
Clinical pearls
- FENa <1% = prerenal, >2% = intrinsic renal (not reliable if diuretics given — use FEUrea instead)
- Most common cause of AKI in hospitalized patients is prerenal from volume depletion
Source and review
- KDIGO AKI Guidelines 2012. Last reviewed: 2024-11-01