Pre and Post-Operative Lactate Levels and Lactate Clearance in Predicting in Hospital Mortality After Surgery for Gastrointestinal Perforation

Gastrointestinal perforation is a life-threatening surgical emergency associated with significant morbidity and mortality. Early risk stratification is essential for optimizing perioperative management and improving outcomes. Lactate levels are a biomarker of tissue hypoxia and perfusion, and their clearance postoperatively may help predict in-hospital mortality. Objective: The objective of this study is to evaluate the prognostic significance of preoperative and postoperative lactate levels and lactate clearance in predicting in-hospital mortality following surgery for gastrointestinal perforation Methods: After the ethical approval from the institutional review board, this retrospective observational study was conducted at Department of general surgery in Dr Ruth KM PFAO civil hospital Karachi, from 1st October 2024 to 30th December 2024.Through non-probability consecutive sampling, 100 patients aged 18 and above, both genders, undergoing emergency surgery for gastrointestinal perforation, and availability of preoperative and postoperative lactate measurements. Results: Survivors had a significantly lower preoperative lactate level (3.17 ± 1.7 mmol/L) compared to non-survivors (6.7 ± 1.9 mmol/L), p < 0.0001. Similarly, postoperative lactate levels were markedly lower in survivors (2.6 ± 0.8 mmol/L) than in non-survivors (6.8 ± 2.3 mmol/L), also with a p-value < 0.0001. The area under the curve (AUC) for preoperative lactate was 0.905 (95% CI: 0.843–0.967, p < 0.0001), while postoperative lactate had an AUC of 1.0 (95% CI: 1.0–1.0, p < 0.0001), indicating perfect predictive ability. Conclusion: Hospital mortality rates of patients undergoing gastrointestinal perforation surgeries can best be predicted through lactate assessments performed before and after surgery.