Lactate levels predict mortality and need for peritoneal dialysis in children undergoing congenital heart surgery.

Background: The purpose of this study was to investigate whether an initial post-operative lactate level is a predictor of mortality, need for peritoneal dialysis (PD), duration of intubation or length of stay (LOS) in the intensive care unit (ICU) in children undergoing cardiac surgery.

Method: A retrospective, observational follow-up study was conducted in 206 children undergoing cardiac surgery from 2006 to 2007. Multivariate logistics regression analyses were performed to determine whether the lactate level was an independent risk factor. The lactate concentration at arrival in the ICU, outcome and risk factors (patient demographics, surgical complexity, duration of cardiopulmonary bypass and inotropic score) were obtained from the electronic patient data management program and medical records.

Result: The median (interquartile range) lactate level was 1.9 mmol/l (1.3-2.7) in children immediately after cardiac surgery and a mortality of 3.9%. Eight percent of the children had a lactate level higher than 4.5 mmol/l. An increased lactate level ≥4.5 mmol/l resulted in an odds ratio (95% confidence intervals) of 8.4 (1.5-46.1) for mortality and an odds ratio of 16.9 (2.7-106.8) for PD after adjusting for Risk Adjustment for Congenital Heart Surgery 1. Because of the low number of deaths, limited confounder analysis was performed. Duration of intubation and LOS in the ICU were not associated with the initial lactate level when adjusting for confounders.

Conclusion: The initial post-operative lactate level was a predictor of mortality and need for PD in children undergoing surgery for congenital heart disease.