Systemic Inflammatory Indices and Disease Severity in Acute Colonic Pseudo-Obstruction: An Exploratory Retrospective Study

Background: Acute colonic pseudo-obstruction (ACPO) is associated with substantial morbidity and mortality, particularly when complicated by ischemia or perforation. Although radiological assessment remains central to clinical monitoring, objective biomarkers reflecting disease severity and clinical course are limited. This study was designed as an exploratory, hypothesis-generating analysis to examine associations between composite systemic inflammatory indices and ACPO severity. Methods: In this retrospective observational study, 47 patients diagnosed with ACPO and 50 age- and sex-matched healthy controls were analyzed. Neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) were calculated from peripheral blood counts obtained at hospital admission. Associations between these indices and subsequent surgical intervention were evaluated, recognizing surgery as a decision-dependent clinical endpoint. Results: SIRI and SII values were significantly higher in patients with ACPO compared with controls. Within the ACPO cohort, NLR and SIRI demonstrated the strongest within-cohort discrimination for surgical intervention (AUC 0.840, 95% CI: 0.722–0.958 and AUC 0.835, 95% CI: 0.718–0.952, respectively). A multivariate model incorporating SIRI (>3.52) and colonic diameter (>12 cm) achieved 88.9% within-sample classification accuracy. Conclusions: This exploratory study demonstrates that composite inflammatory indices derived from routine blood counts are associated with disease severity and clinical course in ACPO. These preliminary findings require validation through larger, prospective, multicenter studies incorporating disease control groups, objective outcome measures, and formal validation frameworks before any clinical utility can be established.