Fluid Balance in Acute Kidney Injury in Critically Ill Patients

This prospective observational cohort study at Assiut University Hospital ICU investigates the association between fluid balance in the first 48 hours of admission and acute kidney injury (AKI) development. Critically ill adults (≥18 years) without AKI at baseline will undergo routine monitoring: hourly fluid intake/output (IV fluids, blood products, urine, drains, insensible losses), daily weights, serial labs (SCr, BUN, electrolytes, albumin, CRP), and clinical/hemodynamic assessments. AKI is defined/staged by KDIGO criteria within 7 days. Sample size is 120 (Epi-Info calculated, 38.4% expected AKI incidence). Data analysis will examine if positive/negative balances predict AKI incidence, severity, RRT need, ICU stay, and 28-day mortality, using AKI-FB risk score. No interventions; standard care only.