Association Between Preoperative Systemic Immune Inflammation Index and Postoperative Sepsis in Patients with Intestinal Obstruction: A Retrospective Observational Cohort Study.

Background: Sepsis is a severe complication that results in increased morbidity and mortality after intestinal obstruction surgery. This study examined the role of preoperative systemic immune inflammation index (SII) for postoperative sepsis in intestinal obstruction patients. Methods: Data on patients who underwent intestinal obstruction surgery were collected. SII was determined and separated into two groups (<= 1792.19 and >1792.19) according to the optimal cut-off value of SII for postoperative sepsis. The odds ratio (OR) is calculated for the correlation between SII and postoperative sepsis. Additional analyses were used to estimate the robustness of SII. Results: A total of 371 intestinal obstruction patients undergoing surgery were included in the final cohort, and 60 (16.17%) patients developed postoperative sepsis. Patients with an SII > 1792.19 had a significantly higher risk for developing postoperative sepsis after multivariable adjustment [adjusted odds ratio = 2.12, 95% confidence interval: [1.02-4.40]]. The analysis of interaction showed no correlation between the preoperative SII and postoperative sepsis regarding age, hypertension, American Society of Anesthesiologists classification, blood loss, albumin, hemoglobin, creatinine, and leukocyte (all interactions p > .05). In subgroup analysis, all statistically significant subgroups showed that SII was a risk factor for postoperative sepsis (all p < .05). The analyses of subgroups and interactions revealed that the interaction effect of a preoperative SII > 1792.19 and postoperative sepsis remained significant. A sensitivity analysis confirmed the robustness of the results. Conclusions: A preoperative SII > 1792.19 was a risk factor for postoperative sepsis in patients undergoing intestinal obstruction surgery.