Pre and postoperative lactate levels and lactate clearance in predicting in-hospital mortality after surgery for gastrointestinal perforation

BACKGROUND: This study aimed to compare the prognostic significance of pre and postoperative lactate levels and postoperative lactate clearance in the prediction of in-hospital mortality after surgery for gastrointestinal (GI) perforation. METHODS: Among patients who underwent surgery for GI perforation between 2013 and 2017, only patients whose lactate were measured before and after surgery were included and divided into an in-hospital mortality group and a survival group. Data on demographics, comorbidities, pre and postoperative laboratory test results, and operative findings were collected. Risk factors for in-hospital mortality were identified, and receiver-operating characteristic (ROC) curve analysis was performed for pre and postoperative lactate levels and postoperative lactate clearance. RESULTS: Of 104 included patients, 17 patients (16.3%) died before discharge. The in-hospital mortality group demonstrated higher preoperative lactate (6.3 ± 5.1 vs. 3.5 ± 3.2, P = 0.013), SOFA score (4.5 ± 1.7 vs. 3.4 ± 2.3, P = 0.004), proportions of patients with lymphoma (23.5% vs. 2.3%, P = 0.006), and rates of contaminated ascites (94.1% vs. 68.2%, P = 0.036) and lower preoperative hemoglobin (10.4 ± 1.6 vs. 11.8 ± 2.4, P = 0.018) compare to the survival group. Multivariate analysis revealed that postoperative lactate (HR 1.259, 95% CI 1.084-1.463, P = 0.003) and preoperative hemoglobin (HR 0.707, 95% CI 0.520-0.959, P = 0.026) affected in-hospital mortality. In the ROC curve analysis, the largest area under the curve (AUC) was shown in the postoperative lactate level (AUC = 0.771, 95% CI 0.678-0.848). CONCLUSION: Of perioperative lactate levels in patients underwent surgery for GI perforation, postoperative lactate was the strongest predictor for in-hospital mortality.