Efficacy of Modified POSSUM Scoring System in Predicting Morbidity and Mortality in Cases of Perforated Peritonitis

Abstract

Jahid Husain S*, Gulam Nabi, Milind H Iddalagi and Syed Saad

Background: Even though surgical peritonitis being one of the most common problem faced by surgeons in emergency, still the post-operative period of perforated peritonitis is unpredictable most of the times and it carries considerable morbidity and mortality. It therefore becomes necessary for a scoring system that predicts the post-operative period.

There have been many scoring systems developed, including the American Society of Anesthesiologists (ASA) for general risk prediction, Acute Physiology and Chronic Health Evaluation III (APACHE III) for intensive care, and the Goldman Index for cardiac-related problems after surgery. In our study, we propose to use the modified POSSUM scoring to predicting the morbidity and mortality in perforated peritonitis.

Methods: Patients presenting to MVJ Medical College and Research Hospital, Hoskote from December 2020- November 2022 (24 Months). All cases of established peritonitis admitted in Department of General Surgery of MVJMC&RH. A total of 50 patients admitted who underwent emergency laparotomy for perforated peritonitis at MVJ Medical College and Research Hospital. Patients presenting with peritonitis was evaluated with detailed history and clinical examination and pre-operative physiological variables was collected and intra-operative variables were assessed and the expected outcome was measured by using POSSUM equation. Patient was followed up for 4 week after the surgery. Outcome and complications were recorded. Statistical analysis done by expected and observed outcome (chi-square test).

Results: In our study, 50 patients were studied and male outnumbered females. The most common site of perforation in gastrointestinal tract was gastric perforation followed by duodenum, ileum and appendix. Crude mortality rate of 10%. Crude morbidity rate of 60% and most of the patients presented with multiple complications. Maximum number of patients presented late >24 hrs and almost 50% mortality in the group where patient presented late (>48 hrs). Physiological variables such as cardiovascular system, blood pressure, hemoglobin, blood urea, serum potassium and operative variables such as operative complexity, multiple procedure, presence of malignancy, mode of surgery were significant. Additional factor perforation to operation time was included in our study and found to be significant. Predicted risk of mortality and morbidity was calculated and compared with the observed mortality and morbidity. An Observed to Expected ratio (O: E) for mortality was 1.020 (there was no significant difference between the predicted and observed values) (p=0.980) and for morbidity was 1.005 (there was no significant difference between the predicted and observed values) (p=0.934). For mortality and morbidity, positive predictive value was 80% and 97%, negative predictive value was 95% and 93%, sensitivity was 80% and 97%, specificity was 95% and 93% respectively. POSSUM score as it’s better at predicts mortality and morbidity, but it’s over predict morbidity in lower risk groups.

Conclusion: POSSUM scoring system is better since it’s include both physiological and operative parameters and can be used as a significant tool for predicting outcomes in perforated peritonitis. Factors such as cardiovascular system, blood pressure, hemoglobin, blood urea, serum potassium, operative complexity, multiple procedure, presence of malignancy, mode of surgery were significant to predict post-operative outcomes independently. Depends on the scoring system, patients attender can be counselled pre-operatively and prior correction of risk factors can be done. Strict vigilance and prompt adjustment of the verified parameters can improve the patient's overall health and decrease morbidity and mortality. Widespread awareness and education about perforated peritonitis, early referrals, early diagnosis and prompt treatment must be implemented to shorten the duration of perforation to operation time.