Determinants of Septic Shock and 90-Day Mortality After Postoperative Healthcare-Associated Intra-Abdominal Infection: The Sepsi-Pop Study, a Multicenter Retrospective Study

BACKGROUND: Healthcare-associated intra-abdominal infections (HC-IAIs) after abdominal surgery are a major cause of sepsis in intensive care units. While predictors of mortality are well established, the determinants of septic shock remain insufficiently defined. METHODS: This retrospective multicenter study included all adult patients who developed HC-IAI after initial abdominal surgery between 2009 and 2021 in three French intensive care units. Clinical, microbiological, and management data were collected. Independent predictors of septic shock and 90-day mortality were identified using multivariate logistic regression. RESULTS: Among 271 patients [median age 65 (55-74) years, 75.6% with cancer], septic shock occurred in 154 (57%) and 90-day mortality was 14.4%. Independent predictors of septic shock were American Society of Anesthesiologists physical status classification >II [odds ratio (OR): 2.48 (1.42-4.40)], absence of cancer [OR: 2.03 (1.03-4.12)], antibiotic exposure within 48 hours [OR: 1.85 (1.03-3.38)], fungal colonization [OR: 4.37 (1.23-20.94)], and Escherichia coli bacteremia [OR: 3.25 (1.15-10.78)]. Female sex was protective [OR: 0.57 (0.33-0.99)]. The 90-day mortality was independently associated with American Society of Anesthesiologists physical status classification >II [OR: 2.83 (1.08-7.97)], age [OR: 1.10 (1.05-1.16)], Sequential Organ Failure Assessment at reoperation [OR: 1.20 (1.05-1.38)], fungal colonization [OR: 14.36 (2.50-89.21)], and treatment failure [OR: 12.15 (2.09-81.90)], whereas effective source control was protective [OR: 0.22 (0.04-0.84)]. CONCLUSIONS: Determinants of septic shock and 90-day mortality partly overlap but differ in therapeutic implications. Fungal colonization and patient frailty emerged as shared risk factors, while mortality was influenced by age, organ failure, and inadequate source control. Early identification of high-risk profiles and timely, targeted interventions may improve outcomes in postoperative HC-IAI.