Prognostic Value of the HCO₃-to-Lactate Ratio in Acute Mesenteric Ischemia: A Retrospective Analysis

Acute mesenteric ischemia (AMI) is a life-threatening emergency with persistently high mortality rates, requiring improved tools for perioperative risk assessment. This study investigates the real-world outcomes of patients with occlusive arterial AMI undergoing surgery, focusing on predictors of short-term mortality.

A retrospective, single-center analysis was conducted on patients undergoing emergent mesenteric surgery for occlusive arterial AMI between January 2015 and May 2024. The primary outcome was 30-day survival; secondary outcomes included predictors of in-hospital mortality based on preoperative laboratory parameters.

Sixty patients (mean age 75 ± 12 years) were included, with a 30-day survival rate of 45%. Of the 60 patients, 15 (75%) with acute-on-chronic symptoms (n = 20) survived, compared to 12 (30%) with acute onset (n = 40) (P = 0.003). Multivariate Cox regression identified lactate, bicarbonate (HCO₃), the HCO₃-to-lactate ratio, and neutrophil count as predictors of 30-day mortality. The HCO₃-to-lactate ratio ≤10 demonstrated high predictive accuracy (area under the curve 0.832, sensitivity 90.6%, specificity 75%). In acute-onset cases, excluding acute-on-chronic symptoms improved specificity to 100%.

The HCO₃-to-lactate ratio is a robust prognostic marker in occlusive arterial AMI, reflecting both tissue hypoperfusion and impaired metabolic compensation. These findings support its potential utility in risk stratification and in guiding clinical decision-making in the emergent management of AMI.