The Aggregate Index of Systemic Inflammation and Risk of Perforation, Mortality, and Surgery in Ileus

Abstract This article aims to evaluate the relationship between the aggregate index of systemic inflammation (AISI) and the occurrence of perforation, the likelihood of surgical management, and in-hospital mortality in patients with ileus, and to assess its diagnostic performance in comparison with other hematological inflammatory indices. This prospective observational study was conducted in the emergency department of a tertiary-care hospital. Adult patients (≥ 18 years) diagnosed with ileus based on clinical, radiological, and laboratory findings were consecutively enrolled. Demographic characteristics, comorbidities, and laboratory parameters obtained at presentation were recorded. The primary outcome was intestinal perforation, while secondary outcomes were the likelihood of surgical management and in-hospital mortality. Receiver operating characteristic (ROC) analysis and multivariable logistic regression were performed to evaluate the diagnostic and independent prognostic value of AISI. A total of 265 patients were included. Intestinal perforation occurred in 12 patients (4.6%), in-hospital mortality in 20 (7.6%), and 110 patients (42%) underwent surgical management. AISI demonstrated good discriminatory performance for perforation (AUC, 0.780) and moderate performance for mortality (AUC, 0.638) and surgical management (AUC, 0.620). In multivariable analysis, AISI was independently associated with the likelihood of perforation (adjusted OR, 1.12 per 1,000-unit increase; 95% CI, 1.04–1.20; p = 0.004) and the likelihood of surgical management (adjusted OR, 1.16; 95% CI, 1.06–1.27; p = 0.002), but not with in-hospital mortality (p = 0.236). Age remained independently associated with mortality (adjusted OR, 1.05 per year; 95% CI, 1.01–1.08; p = 0.011). Overall model explanatory power was modest. AISI was independently associated with the likelihood of perforation and surgical management but not with in-hospital mortality. Although AISI may provide supportive information for early risk stratification in patients with ileus, its limited specificity and modest overall predictive performance indicate that it should be used only as an adjunct to clinical assessment rather than as a standalone decision-making tool.