POSSUM: A Scoring System for Perforative Peritonitis

Perforative peritonitis carries considerable morbidity and mortality with the postoperative period unpredictable most of the times. It therefore becomes necessary for a scoring system that predicts the post-operative outcome. POSSUM (Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity) helps in predicting the post-operative morbidity and mortality in these patients. POSSUM scores are based on 12 physiological factors and 6 operative factors. In our study, we included two more factors, which are specifically important in perforative peritonitis; they are, perforation to operation time and the presence of co-morbidity. The presence of these factors significantly affects the post-operative status. Through this prospective study, we can predict which patients are at a higher risk of death or complication and give appropriate management as necessary.

Our sample size was 50 patients with perforative peritonitis. The study was conducted in single unit from September 2013 to August 2014. Data was collected based on POSSUM scoring system. Outcome of the patients was recorded as death / alive; complicated / uncomplicated and statistical analysis was done by comparing the expected and observed outcomes.

By applying linear analysis, an observed to expected ratio of 1.005 was obtained for mortality and 1.001 for morbidity. There was no statistically significant difference between the observed and expected mortality rates (χ(2) = 3.54, p = 0.316) and morbidity rates (χ(2) = 2.40, p = 0.792). It was found to be comparable with other studies. The factors independently studied; perforation to operation time and presence of co-morbidity were statistically significant with respect to outcome (p<0.05).

Although a small sample size is the limitation of this study, POSSUM scoring system is a good indicator of postoperative outcome in patients with perforative peritonitis and was applicable in our setup. It is useful in identifying high risk patients and give preferential care to them for better outcome. Inclusion of factors like perforation to operation time and co-morbid status can improve the scoring system and better care can be provided.