Reflections on: Lactate dynamics in cardiac surgery

Hadipourzadeh, et al are congratulated for their retrospective research endeavor, studying the relationship between lactate levels and postoperative renal dysfunction, in 395 patients undergoing coronary artery bypass grafting surgery (CABG). 1 However, the lactate dynamics can be intricate enough to warrant further discussion.Hyperlactatemia can effectively result from the anaerobic or aerobic pathways, as it relates to either an excessive production or a reduced clearance of lactate.Of note, the former manifests in nearly half of the cardiac surgical patients, wherein being multifactorial in etiology, hyperlactatemia might not necessarily be synonymous with an underlying hypoxic milieu. 2,3Emphasizing upon the same, a 2024 scoping review by de Castro Teixeira et al outline cardiopulmonary bypass (CPB) time, tissue hypoperfusion and, the use of vasoactive drugs and corticosteroids, as the major factors associated with lactate elevation in cardiac surgery, alongside suggesting relevant connections between perioperative hyperlactatemia (especially early-onset) and outcomes. 2Having said that, the steroid practice in the Hadipourzadeh et al study, remains to be clarified for the readers. 1 Moreover, the authors happen to report the use of intraoperative hemodynamic infusions qualitatively without accounting for the corresponding doses. 1 Literature exists to relate quantitative parameters such as vasoactive-inotropic score (VIS) with acute kidney injury (AKI) in surgical settings like the index study, as highlighted in a systematic review and meta-analysis by Sun, et al including a total of 58 studies and 29,920 patients, with 34 studies eventually eligible for the meta-analysis. 1,4In addition to reiterating the fact that postoperative renal dysfunction was under investigation in the present study, it ought to be borne in mind that the catecholamines can simultaneously result in lactate elevation given their actions on the glucose metabolism. 1,2ven in this regard, the links between the glucose and lactate metabolism can be difficult to overlook, particularly