The effect of hyperlactatemia timing on the outcomes after cardiac surgery

AbstractBackgroundSeveral studies linked postoperative hyperlactatemia to worse outcomes in adult patients undergoing cardiac surgery. However, data on the effect of timing of hyperlactatemia on outcomes are scarce. We sought to determine the prevalence of early hyperlactatemia (EHL) and its impact on clinical outcomes compared to late hyperlactatemia (LHL) in patients undergoing ACS procedures.ResultsWe included 305 consecutive adult patients who underwent cardiac surgery procedures between July 2017 and Nov 2019 at a single institution. Lactate level was measured in the first 10 h after surgery and EHL was defined as lactate level > 3 mmol/L in the first hour after surgery. Logistic regression analysis was performed to determine predictors of EHL. Seventeen percent (n= 52) had EH while 83% (n= 253) did not. Patients with EHL had significantly longer cardiopulmonary bypass (P= 0.001) and cross-clamp (P= 0.001) times due to increased surgical complexity in this group. Early hyperlactatemia was associated with increased post-operative extracorporeal membrane oxygenation (ECMO) support (0% vs 5.7%,P< 0.001), longer intensive care unit stay (P= 0.004), and increased hospital mortality (0% vs. 3.8%,P= 0.009). Cardiopulmonary bypass time (OR 1.001; 95% CI 1.011–1.012,P= 0.02) and glucose level (OR 1.2; 95% CI 1.1–1.3,P= 0.003) were independently associated with increased rate of EHL. In contrast, diabetes mellitus (OR 0.26; 95% CI 0.12–0.55,P< 0.001) significantly attenuated the rate of EHL.ConclusionsEarly hyperlactatemia after cardiac surgery was associated with increased morbidity and mortality. Late hyperlactatemia was very common and had a self-limiting and benign course.