Validation of lactate clearance at 6 h for mortality prediction in critically ill children

Abstract

Background and Aims: To validate the lactate clearance (LC) at 6 h for mortality prediction in Pediatric Intensive Care Unit (PICU)-admitted patients and its comparison with a pediatric index of mortality 2 (PIM 2) score. Design: A prospective, observational study in a tertiary care center. Materials and Methods: Children <13 years of age, admitted to PICU were included in the study. Lactate levels were measured at 0 and 6 h of admission for clearance. LC and delayed or nonclearance group compared for in-hospital mortality and compared with PIM 2 score for mortality prediction. Results: Of the 140 children (mean age 33.42 months) who were admitted to PICU, 23 (16.42%) patients died. For LC cut-off (16.435%) at 6 h, 92 patients qualified for clearance and 48 for delayed or non-LC group. High mortality was observed (39.6%) in delayed or non-LC group as compared to clearance group (4.3%) (P = 0.000). LC cut-off of 16.435% at 6 h (sensitivity 82.6%, specificity 75.2%, positive predictive value 39.6%, and negative predictive value 95.7%) correlates with mortality. Area under receiver operating characteristic (ROC) for LC at 6 h for mortality prediction was 0.823 (P = 0.000). The area under ROC curve for expected mortality prediction by PIM 2 score at admission was 0.906 and at 12.3% cut-off of PIM 2 Score was related with mortality. The mean PIM 2 score was high in delayed or non-LC group (25.25%) compared to LC group (10.95%) (P = 0.004). Conclusion: LC cut-off <16.435% at 6 h was associated with high mortality.