Alactic base excess as an early predictor of sepsis-associated acute kidney injury: a prospective observational study

Sepsis-associated acute kidney injury (SA-AKI) is a major contributor to morbidity and mortality in critically ill patients. Early detection and intervention are essential for improving clinical outcomes. This study investigates the predictive utility of alactic base excess (ABE) as an early biomarker for SA-AKI within the first 24 h of hospital or emergency department admission.

A prospective observational study was conducted in a tertiary care hospital in Eastern India from May 2022 to April 2023. Adult patients (≥ 18 years) diagnosed with sepsis at hospital/emergency/intensive care unit (ICU) admission were enrolled. ABE was calculated at 0, 12, and 24 h after admission to hospital or emergency department by adjusting standard base excess for serum lactate levels. The primary outcome was the development of acute kidney injury (AKI), defined by Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Secondary outcomes included AKI severity, stratification by ABE ranges, and in-hospital mortality.

Among 369 enrolled patients, 159 (43%) developed AKI, and 66 (17.9%) required renal replacement therapy (RRT). Baseline ABE remained a significant independent predictor, with each 1 mmol/L increase (less negative value) associated with an 11% reduction in AKI risk (adjusted OR 0.89, 95% CI 0.80-0.99, p = 0.030). More negative baseline ABE values were significantly associated with both increased AKI incidence and mortality. ABE measurements at 12 and 24 h were not independently predictive.

Baseline ABE is a cost-effective, easily obtainable biomarker that independently associates with SA-AKI and correlates with in-hospital mortality. Its early use in sepsis management may improve risk stratification and outcomes, especially in resource-limited settings. Multicenter validation is recommended. Trial registration number The study was registered with the Clinical Trial Registry of India (CTRI/2022/07/044168), dated 20/07/2022.