Prediction of Outcome in Critically ill Patients with Perforation Peritonitis Using APACHE-II Scoring System

Abstract

Background: Perforation peritonitis is a common condition encountered in surgicalemergency in third world countries and most of these patients are managed in critical care units. APACHE-II scoring system was outlined in 1985 by Knaus et al and is still in use for the prediction of outcome in critical care patients. Aim: To find out the level of accuracy of APACHE-II scoring system in the prediction of outcome in critically ill patients with perforation peritonitis. Methodology: Study was carried out in 10 bedded ICU in Lahore General Hospital, Lahore, Pakistan from 2012 to 2016. Five hundred and seventeen patients with perforation peritonitis were included in the study after their informed consent. Prediction of outcome for each patient was done through APACHE-II equation by using the obtained variables. Actual/Observed outcome of each patient was documented in the form of discharge from ICU or death in the ICU. Predicted mortality rates were compared to the actual/observed mortality rates and Standardized Mortality Ratios (SMR), sensitivity and specificity were calculated. Statistical analysis was done using Software Package for windows, IBM SPSS version 20. Area under the ROC curve was measured to test the discrimination. Standardized Mortality Ratios were calculated with ninety five percent confidence intervals and difference between predicted and observed mortality rates were analyzed. Results: Mean APACHE-II score of 517 patients included in our study was (17.39+5.36) with minimum score of 9 and maximum score of 38. Sensitivity, specificity and diagnostic value of APACHE-II scoring system turned out to be 97.7%, 90.7% and 91.87% respectively with an SMR of 0.696. Area under the Receiver Operating Characteristics Curve was found to be 0.907. Conclusion: APACHE-II scoring system is a reliable predictor of outcome in criticalcare patients with perforation peritonitis.