Abstract / Summary
Acute mesenteric ischemia (AMI) is a life-threatening abdominal emergency with persistently high mortality. Although lactate is widely used as a marker of tissue hypoperfusion, most previous studies have focused on preoperative measurements. This study evaluated the association between serial postoperative lactate levels and in-hospital mortality in patients undergoing surgery for AMI. Ninety-eight patients who underwent surgery for AMI at Adana City Training and Research Hospital between 2018 and 2024 were retrospectively analyzed. Venous blood-gas lactate levels obtained at postoperative hours 0, 6, 12, and 24 were evaluated. The primary endpoint was in-hospital mortality. Prognostic discrimination was assessed using receiver operating characteristic (ROC) analysis, and multivariable logistic regression was used to evaluate the association of 24-hour lactate with mortality after adjustment for age, APACHE II score, and immediate postoperative lactate. Mean age was 70.1 years; 53.1% were male. Overall in-hospital mortality was 65.3% (64/98). Among the evaluated time points, the 24-hour postoperative lactate level had the highest observed AUC for in-hospital mortality (AUC: 0.855; 95% CI: 0.769–0.918). The internally derived Youden threshold of > 22 mg/dL (> 2.44 mmol/L) had a sensitivity of 73.4% (95% CI: 61.5–82.7) and specificity of 91.2% (95% CI: 77.0–97.0). After adjustment for age, APACHE II score, and postoperative hour-0 lactate, the 24-hour lactate level remained associated with in-hospital mortality (adjusted OR per 10 mg/dL increase: 2.01; 95% CI: 1.09–3.70; p = 0.026). In this retrospective cohort, higher postoperative 24-hour lactate levels were associated with in-hospital mortality and had the highest observed AUC among the evaluated postoperative time points. However, the > 22 mg/dL threshold was derived from the same cohort and should be considered exploratory. Prospective multicenter studies with external validation are required before this threshold is used for clinical decision-making.