Intraoperative lactate as an early risk marker in laparoscopic liver resection and its association with modifiable hemodynamic parameters: a retrospective cohort study

PURPOSE: Early postoperative lactate ≥ 3 mmol/L is associated with adverse outcomes following open hepatectomy; however, the prognostic utility of intraoperative lactate in laparoscopic liver resection (LLR) and its associations with hemodynamic parameters remain unclear. METHODS: This retrospective cohort study included adults undergoing LLR at a university hospital between January 2017 and August 2024. The predictor was peak arterial lactate from skin incision to PACU discharge, dichotomized at 3 mmol/L. The primary outcome was a 30-day composite of all-cause mortality, post-hepatectomy liver failure (PHLF), or acute kidney injury (AKI). As a secondary objective, associations between intraoperative lactate ≥ 3 mmol/L and prespecified hemodynamic exposures (net fluid balance, vasopressor dose, and indices of low mean arterial pressure (MAP), low or high stroke volume variation (SVV), and low cardiac index) were explored using multivariable logistic regression models. RESULTS: Among 257 patients, 143 (55.6%) had lactate ≥ 3 mmol/L. The composite outcome was more frequent in patients with lactate ≥ 3 mmol/L than in those with lactate < 3 mmol/L (15.4% vs. 4.4%; risk difference, 11.0%; 95% confidence interval, 3.6-18.3%), and discrimination was modest (AUC 0.695). AKI accounted for most events (12.6% vs. 0.9%; risk difference, 11.7%; 95% confidence interval, 5.8-18.2%); mortality and PHLF were similar. Lower net fluid balance and greater exposure to low MAP and low SVV were associated with lactate elevation, whereas vasopressor dose, high SVV, and low cardiac index were not. CONCLUSION: In LLR, intraoperative lactate ≥ 3 mmol/L showed modest discrimination for the 30-day composite outcome, driven primarily by AKI.