Validation of the Mannheim peritonitis index as a prognostic tool in mortality and morbidity of peritonitis secondary to hollow viscus perforation

Abstract

Background: Peritonitis due to hollow viscus perforation is a surgical emergency associated with high mortality. Early risk stratification is essential. The Mannheim peritonitis index (MPI) is a validated prognostic tool. Aims and Objectives: This study aimed to evaluate the effectiveness of the MPI in predicting mortality, assess its role in morbidity prediction, and determine its prognostic value in risk stratification of perforation peritonitis. Materials and Methods: A cross-sectional study was conducted on 60 patients with perforated peritonitis over 24 months. Clinical, laboratory, and intraoperative variables were recorded. MPI scores were calculated. Associations with mortality and morbidity were analyzed using Chi-square tests. Receiver operating characteristic analysis was performed to assess diagnostic performance. Results: The most affected age group was 41–50 years (28.3%). Males constituted 81.7%. Organ failure occurred in 33.3%, and malignancy in 10%. Appendicular perforation was the most common source (35%), followed by gastric (28.3%) and duodenal (20%) perforations. Diffuse peritonitis was present in 91.7%. Post-operative complications occurred in 35.3%, predominantly surgical site infection (23.5%). Overall mortality was 15%. Mortality was higher with organ failure (45% vs. 0%), malignancy (60% vs. 10.9%), and colonic perforation (80%). Fecal exudate showed the highest mortality (71.4%) (P<0.0001). MPI demonstrated strong predictive performance with an area under the curve of 0.964. At a cutoff ≥26, sensitivity was 88.9%, specificity was 94.1%, positive predictive value was 72.7%, negative predictive value was 97.9%, and accuracy was 93.3%. Conclusion: The MPI demonstrated high accuracy in predicting mortality and supported clinical risk stratification in perforated peritonitis. However, its utility in morbidity prediction was limited.