Monitor hourly urine output per kg body weight.
Target UO: ≥ 0.5 mL/kg/hr in adults. < 0.5 for 6 hrs = KDIGO AKI Stage 1. < 0.3 for 24 hrs = Stage 3. Burn patients: target 0.5–1.0. Children: target 1.0 mL/kg/hr. Adequate UO is the simplest bedside marker of end-organ perfusion. Foley catheter ensures accurate measurement in critical patients.