High Arterial Lactate Levels after Hepatic Resection Are Associated with Low Oxygen Delivery and Predict Severe Postoperative Complications

High End-Surgery Arterial Lactate Concentration (ES-ALC) predicts poor outcome after hepatectomy. The aim of this study was to identify intraoperative hemodynamic parameters predicting high ES-ALC during elective liver resection. Patients who underwent liver resection between 2017 and 2018, under FloTrac/EV1000TM hemodynamic monitoring, were included. The ESALC cutoff best predicting severe postoperative complications was identified. Association between high ES-ALC and preoperative and intraoperative variables was assessed. 108 patients were included; 90-day mortality was 0.9% and severe morbidity 14.8%. ES-ALC cutoff best discriminating severe complications was 5.05 mmol/L. Patients with ES-ALC > 5.0 mmol/L had a relative risk of severe complications of 2.8% (p = 0.004). High ES-ALC patients had longer surgery and ischemia duration, larger blood losses and higher requirements of fluids and blood transfusions. During surgery, hemoglobin concentration and oxygen delivery (DO2) decreased more significantly in patients with high ES-ALC, although they had similar values of stroke volume and cardiac output to those of other patients. At multivariate analysis, surgery duration and lowest recorded DO2 value were the strongest predictors of high ES-ALC. ES-ALC > 5.0 mmol/L in elective liver resection predicts postoperative morbidity and is essentially driven by the impaired DO2. Timely correction of blood losses might prevent the ES-ALC increase.