Systematic review on peri-operative lactate measurements to predict outcomes in patients undergoing liver resection.

Lactate measurements have proven utility as a triage tool, therapeutic guide, and prognostic indicator, with broad use in Acute Care and transplantation. Its value in guiding therapy and predicting outcomes following liver resection is less well-defined. This systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines assessed the relationship between peri-operative lactate levels and morbidity and mortality after liver resection. Seven relevant studies comprising 2573 patients in total were identified. Six studies assessed intra-operative or early postoperative lactate levels, one publication examined pre-operative levels. All studies demonstrated a significant association between peri-operative lactate levels and adverse outcomes. The influence of pre-operative diabetes and cirrhosis on postoperative lactate levels was shown in one study each, no study assessed the association of lactate with post-hepatectomy liver failure according to defined criteria. The heterogeneity of study measurements and end-points precluded a meta-analysis from being performed. Early postoperative lactate >3-3.7 mmol/L is associated with mortality but validation of clear cut-off levels for outcome prediction is pending. Literature suggests lactate is a useful predictive marker for outcomes post liver surgery, especially when measured in the early postoperative phase. Further research is required to standardize the use of lactate measurements in a meaningful therapeutic manner.