Prognostic significance of lactate/albumin ratio in respiratory failure and sepsis.

introductionPrognostic markers like SOFA and APACHE-II scores for sepsis and acute respiratory failure (ARF) are often complex for routine use. This study evaluated the lactate-albumin ratio (LAR) as a prognostic marker for in-hospital outcomes, mechanical ventilation, and inotrope requirement.

methodsA prospective cohort study was conducted among ICU and Internal Medicine Unit patients at Manipal Teaching Hospital, approved by the Institutional Review Committee (approval number IRC/MCOMS/584). Arterial samples for ABG values (lactate, PaO2, PaCO2, HCO3, and FiO2) and venous samples for albumin, bilirubin and creatinine were collected on admission. Arterial lactate, serum albumin, LAR and SOFA scores were recorded and compared with in-hospital outcomes. Statistical analyses were performed using SPSS version 25, with ROC-AUC for assessing prognostic markers (LAR, lactate alone) and Delong's test for comparison.

resultAmong 115 sepsis cases, ROC-AUC of LAR for in-hospital mortality (cut-off 1.78), mechanical ventilation (1.28), and inotropes (1.07) were 0.914, 0.881, and 0.819, respectively. Among 99 ARF cases, ROC-AUC for mortality (1.98), ventilation (1.10), and inotropes (1.18) were 0.878, 0.958, and 0.876. Among 43 sepsis + ARF cases, ROC-AUC for mortality (2.14), ventilation (1.20), and inotropes (1.20) were 0.853, 0.874, and 0.849.

conclusionThe lactate-albumin ratio was a better prognostic marker than albumin alone and SOFA score for predicting in-hospital mortality, need for mechanical ventilation and inotropes in sepsis, ARF and combined Sepsis and ARF patients whereas it was statistically equivalent to lactate alone in predicting in hospital outcome. Lactate-albumin ratio also indicated disease progression, where an increase in cut-off value was seen with progressed or severe disease.