Study on evaluation of P-POSSUM scoring system in patients undergoing exploratory laparotomy

Abstract

Background: Emergency exploratory laparotomy carries substantially higher morbidity and mortality than elective surgery, and accurate risk stratification is essential for perioperative decision-making, patient counselling and surgical audit. The Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (P-POSSUM) is widely used for this purpose, but its performance in Indian tertiary surgical units requires local validation. This study aimed to evaluate the validity of P-POSSUM in predicting 30-day postoperative mortality and to characterize the complication profile in patients undergoing emergency exploratory laparotomy. Methods: This prospective observational study was conducted over two years (November 2023 to October 2025) in the Department of Surgery of a tertiary teaching hospital in Northern Maharashtra. A total of 134 patients aged 13 years or older undergoing emergency exploratory laparotomy were enrolled by convenience sampling. Preoperative physiological and intraoperative operative severity variables were recorded and P-POSSUM scores calculated using the standard logistic regression equation. Observed 30-day mortality was compared with P-POSSUM-predicted mortality, and observed-to-expected (O:E) ratios were calculated. Associations between clinical parameters and mortality were assessed using the chi-square test. Results: The mean age was 56.25±15.04 years, with a male predominance (53.7%). Perforation peritonitis (41.79%) was the commonest diagnosis, followed by acute intestinal obstruction (29.10%) and appendicular perforation (20.90%). The mean physiological score was 12.05±5.06, operative score 9.31±3.36, and mean predicted mortality was 33.72±24.39%. Overall observed mortality was 23.88% (32/134) compared with an expected mortality of 33.72%, giving an O:E ratio of approximately 0.71, indicating that P-POSSUM overestimated mortality in this surgical cohort. Physiological score >18, higher operative severity, greater blood loss, degree of peritoneal soiling and presence of malignancy were significantly associated with mortality (p<0.05). Postoperative complications occurred in 59.7% of patients, most commonly sepsis (20.90%) and renal failure (19.40%); 63.43% required ICU admission and 40.30% required ventilatory support. Conclusions: P-POSSUM remains a clinically useful risk-stratification tool for patients undergoing emergency exploratory laparotomy in an Indian tertiary surgical unit, but it systematically overestimates mortality, indicating a need for population-specific recalibration to improve its predictive accuracy and surgical audit utility.