Intraoperative Lactate as a Predictor of Complications in Major Surgery

This is the authors' abstract. We don't add key points for this paper.

Background: : Major surgery is associated with substantial physiological stress, alterations in tissue perfusion, changes in oxygen delivery, and metabolic disturbances that may contribute to postoperative complications. Serum lactate is a widely available biomarker that reflects the balance between lactate production and clearance and has been increasingly investigated as a prognostic marker in the perioperative setting. Objective: To review the available evidence regarding the role of intraoperative lactate as a predictor of postoperative complications in patients undergoing major surgery, with emphasis on its prognostic value, timing of measurement, and potential clinical implications. Methods: : A narrative review of the literature was conducted to evaluate studies assessing intraoperative lactate concentrations in adult patients undergoing major surgical procedures. Evidence regarding the association between intraoperative lactate levels and postoperative complications, organ dysfunction, intensive care requirements, and mortality was considered. Results: : Elevated intraoperative lactate concentrations have been associated with an increased risk of adverse postoperative outcomes in several major surgical populations. In particular, higher lactate concentrations measured during or at the end of surgery have been associated with postoperative morbidity, prolonged intensive care and hospital stay, organ dysfunction, and mortality. However, the prognostic value of lactate varies according to the type of surgery, timing of measurement, magnitude and persistence of elevation, and the clinical context. Importantly, intraoperative hyperlactatemia may result from multiple mechanisms, including tissue hypoperfusion and impaired oxygen utilization, but also from catecholamine-mediated glycolysis, hepatic dysfunction, pharmacological effects, and other metabolic processes. Conclusions: : Intraoperative lactate is a promising perioperative biomarker for identifying patients at increased risk of complications following major surgery. Its interpretation, however, should be integrated with hemodynamic parameters, surgical characteristics, comorbidities, and other markers of organ dysfunction rather than considered an isolated predictor. Further prospective studies are needed to establish standardized sampling strategies, clinically meaningful thresholds, and its role within multimodal perioperative risk assessment.