A COMPARATIVE STUDY OF APACHE-II AND P-POSSUM SCORING SYSTEMS IN PREDICTING POSTOPERATIVE MORTALITY FOR PATIENTS UNDERGOING NON-TRAUMATIC EMERGENCY LAPAROTOMY

Abstract

Objeective To compare the predictive ability of the APACHE-II and P-POSSUM scoring systems in predicting thirty day postoperative mortality among patients undergoing non-traumatic emergency laparotomy in a large public sector hospital in Pakistan.

Methods A prospective observational study was carried out at Dr. Ruth KM Pfau Civil Hospital Karachi among patients undergoing non-traumatic emergency laparotomy. APACHE-II and P-POSSUM scores were calculated for each patient using physiological and operative parameters. The mortality was assessed within 30 days of post-operation. Receiver Operating Characteristic (ROC) curve analysis was used to determine the discriminative ability of both scores. Optimal cutoff points were identified using Youden’s Index, and diagnostic accuracy was assessed through sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Results Of 192 patients, the 30-day postoperative mortality rate was 24 (12.5%). Both APACHE-II and P-POSSUM showed excellent discriminatory power, with area under the AUC values exceeding 0.90. The optimal cutoff for APACHE-II mortality risk was 27.35, reporting sensitivity, specificity, PPV, NPV, and diagnostic accuracy of 95.8%, 22.6%, 15.0%, 97.4%, and 31.8% respectively. For P-POSSUM, the optimal cutoff was 49.75, with sensitivity, specificity, PPV, NPV, and diagnostic accuracy of 95.8%, 45.8%, 20.2%, 98.7%, and 52.1% respectively.

Conclusion Both APACHE II and P-POSSUM scores are effective in predicting 30-day postoperative mortality, with P-POSSUM offering superior diagnostic accuracy due to the inclusion ofintraoperative variables.