Association between preoperative systemic inflammation response index and postoperative sepsis in patients undergoing intestinal obstruction surgery: an observational study

Sepsis is a life-threatening complication following intestinal obstruction surgery for which early biomarker-based prediction is needed. The value of the Systemic Inflammatory Response Index (SIRI) remains under-explored in intestinal obstruction. This retrospective analysis included 396 patients who underwent surgery for intestinal obstruction between April 2013 and April 2021. Differences between the sepsis and non-sepsis groups were compared. The optimal cutoff value of SIRI was determined using the ROC curve. The predictive performance of SIRI was compared with that of NLR, PLR, SII, AISI, and NAR using the area under the receiver operating characteristic curve (AUC) with DeLong’s test for paired ROC curves. The correlation between SIRI and postoperative sepsis is analyzed using multivariate logistic regression analysis. Subgroup analysis and sensitivity analysis were employed to assess the robustness of SIRI. A total of 371 patients were included in the final cohort, and 60 (16.17%) developed postoperative sepsis. The AUC of SIRI is better than AISI and there is no significant difference compared to other inflammatory indicators. Patients with an SIRI > 4.53 exhibited a significantly elevated risk for postoperative sepsis after multivariable adjustment [aOR = 3.70, 95% CI (1.59–8.58)]. Interaction analysis revealed no significant effect modification of the SIRI-sepsis association by age, etiology, bowel viability status, bowel location, degree of obstruction, or cancer status (all interaction P > 0.05). Subgroup analysis and sensitivity analysis confirmed the robustness of the significant association between preoperative SIRI > 4.53 and postoperative sepsis. The SIRI stands as a risk factor of postoperative sepsis in patients with intestinal obstruction surgery.