Bilirubin is not an independent predictor of mortality in patients admitted to intensive care with sepsis – A prospective, single-center cohort from South India

Background: Hyperbilirubinemia is frequently observed in critically ill patients with sepsis and is proposed as a prognostic marker for mortality. However, its independent predictive value, particularly when accounting for established severity indices, remains unclear. Methods: We conducted a prospective cohort study in the intensive care unit (ICU) of a tertiary care center in South India from April 2021 to April 2022. Adults (≥18 years) with sepsis were enrolled, excluding those with preexisting liver disease or alternative causes for hyperbilirubinemia. Serum total bilirubin was measured within 48 h of ICU admission and categorized as normal (≤1.2 mg/dL), mildly elevated (1.21–2 mg/dL), or significantly elevated (>2 mg/dL). Demographic, clinical, and laboratory data were collected. The primary outcome was ICU mortality. Univariate and multivariate logistic regression analyses identified the independent predictors of mortality. Results: Among 110 patients, ICU mortality was 29.1%. Nonsurvivors had significantly higher bilirubin levels (6.2 ± 5.5 mg/dL vs. 1.8 ± 2.3 mg/dL, P < 0.001) and higher Acute Physiology and Chronic Health Evaluation II (APACHE-II) scores. Elevated bilirubin was associated with mortality in univariate analysis (univariate odds ratio [OR] 1.3/1 mg/dL increase, 95% confidence interval [CI] 1.2–1.5, P < 0.001). However, after adjusting for APACHE-II score and comorbidity burden, bilirubin was not an independent predictor of mortality (adjusted OR [aOR] 1.3, 95% CI 0.8–2.2, P = 0.266). APACHE-II score remained the only independent predictor (aOR 1.8, 95% CI 1.1–2.9, P = 0.02). Conclusion: While hyperbilirubinemia is associated with increased ICU mortality in sepsis, it is not an independent predictor after accounting for disease severity.