The Value of POSSUM & P-POSSUM as Surgical Audit Tool Predicting Morbidity and Mortality in Emergency Laparotomy

Introduction: Improvement of surgical outcomes in emergency laparotomy surgery remained dubious. Physiology and Operative Severity Score for the enumeration of Mortality (POSSUM) and Portsmouth-POSSUM (P-POSSUM) have been validated in multiple studies. The objective of this study is to determine the value of both as surgical audit tool predicting the morbidity and mortality of emergency laparotomy in a single tertiary centre in Malaysia. Methods: A retrospective review was performed in Hospital Universiti Sains Malaysia after obtaining ethical approval. All adult subjects that underwent emergency abdominal surgery from 2012 until 2015 were reviewed. Data collected were subjects' demography, clinical-pathological profiles and clinical pathway characteristics. Expected morbidity and mortality were calculated using POSSUMs risk prediction model and subsequently compared against the observed outcome. The risk prediction model was analyzed using Hosmer and Lemeshow Goodness of Fit statistical test. Results: Eighty-three (83) subjects were analyzed in this study. The proportion of 30-day in-hospital morbidity was 44 (53.0%) subjects and in-hospital mortality was 12 (14.5%) subjects. Eighteen subjects that developed in-hospital morbidity had suffered a respiratory complication. The observed-to-expected ratio of POSSUM predicting morbidity was 0.9 and P-POSSUM predicting morbidity was 0.8. However, using Hosmer and Lemershow Goodness of Fit statistical analysis, the p-value of less than 0.05 showed both POSSUM and P-POSSUM predicted poor morbidity and mortality across all risk stratifications in this population. Conclusions: POSSUM and P-POSSUM are not suitable for surgical audit tool in this centre because both produce a poor prediction of in-hospital morbidity and mortality in emergency laparotomy.