179 The Predictive Role of APACHE II Score in Patients with Peritonitis at National Hospital Abuja

Abstract Aim This study assesses the predictive role of APACHE II in surgical outcomes of patients managed for peritonitis in Abuja, Nigeria. Method This is a prospective study of consecutive adult patients managed for peritonitis by the general surgery unit of National Hospital Abuja (NHA) within a 19-month study duration (September 2020 through March 2022). Patient characteristics and treatment outcomes were recorded in a structured proforma and analysed using the SPSS, version 25. The accuracy, sensitivity, specificity, and threshold of the APACHE II were derived from the ROC curve analysis and its coordinates. Results There were 54 patients with peritonitis during the study period with a male-to-female ratio of 2.6:1. Complicated appendicitis and trauma were the two leading causes of peritonitis. This study's mortality and morbidity rates were 13.0% and 63.0%, respectively. APACHE II score at admission positively correlated with the likelihood of post-operative mortality, morbidity, number of post-operative complications, ICU admission and length of hospital admission. The average APACHE II score of patients in this study was 7.1±5.2. APACHE II best-predicted mortality by the ROC curve at a threshold point of 9 (sensitivity of 85.7%, specificity of 70.2%, accuracy of 86.8%, P-value 0.002). At a threshold score of 6, APACHE II was significantly associated with the occurrence of post-operative morbidity (sensitivity of 74.3%, specificity of 73.7%, accuracy of 75.2%, P-value= 0.043). Conclusions This study confirms that APACHE II score at admission can predict the outcome of surgery within the first 30 days post-surgery among adult patients who had peritonitis at NHA.