INCIDENCE AND PREDICTORS OF ACUTE KIDNEY INJURY (AKI) IN ICU PATIENTS RECEIVING HIGH-DOSE VASOPRESSORS

Background: Acute kidney injury (AKI) remains a frequent and serious complication in critically ill patients requiring vasopressor therapy. Hemodynamic instability, elevated lactate levels, and fluid imbalance are major contributors to renal dysfunction. Despite advances in critical care, data on the incidence and predictors of AKI in patients receiving high-dose vasopressors in the ICU are limited, particularly in South Asian clinical settings. Objective: To determine the incidence and identify key hemodynamic and metabolic predictors of AKI among intensive care unit patients receiving high-dose vasopressors. Methods: A prospective observational cohort study was conducted at Hameed Latif Hospital, Lahore, over twelve months from january to December 2025. Five hundred adult ICU patients requiring norepinephrine equivalent doses ≥0.1 µg/kg/min for more than six hours were enrolled. AKI was defined using KDIGO criteria. Clinical data, including vasopressor dose, mean arterial pressure (MAP), serum lactate trends, and cumulative fluid balance, were recorded. Multivariate logistic regression identified independent predictors, and associations were expressed as adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Results: The incidence of AKI was 43.6%, with 25.6% Stage 1, 12.4% Stage 2, and 5.6% Stage 3. Independent predictors of AKI included higher vasopressor dose (aOR 1.48; 95% CI 1.22–1.80), lower MAP (aOR 0.87; 95% CI 0.80–0.94), admission lactate ≥4 mmol/L (aOR 2.35; 95% CI 1.40–3.93), and positive fluid balance ≥2 L by day 3 (aOR 1.91; 95% CI 1.28–2.85). AKI was associated with increased mortality (32.6% vs 15.4%) and longer ICU stay (p < 0.001). Conclusion: AKI was common in critically ill patients receiving high-dose vasopressors and was strongly linked to hemodynamic instability, hyperlactatemia, and fluid overload. Optimizing vasopressor titration, maintaining adequate MAP, and preventing excessive fluid accumulation may help mitigate AKI risk and improve outcomes. Keywords: Acute kidney injury, Fluid balance, Hemodynamics, Intensive care units, Lactate, Mean arterial pressure, Vasopressors