Mortality in Surgical Site Infections Post-cardiac Surgery - a Prospective, International Id-iri Study

Abstract

OBJECTIVES Surgical site infections (SSIs) after cardiac surgery increase morbidity and mortality. This multi-center study aimed to identify mortality risk factors associated with SSIs following heart surgery. METHODS Conducted from January to March 2023, this prospective study included 167 patients aged > 16 with post-heart surgery SSIs. The primary focus was on 30-day mortality. Univariate analysis and a multivariate logistic regression model, utilizing the Backward elimination method, were employed to establish the final model. RESULTS A number of factors had substantial correlations to death. These included urinary catheterization [OR 14.197 (90% CI 12.198–91.721)], emergent surgery [OR 8.470 (90% CI 2.028–35.379)], valvular replacement [OR 4.487 (90% CI 1.001–20.627)], higher qSOFA scores [OR 3.147 (90% CI 1.450–6.827)], advancing age [OR 1.075 (90% CI 1.020–1.132)] and postoperative re-interventions within 30 days following SSI [OR 14.832 (90% CI 2.684–81.972)]. No pathogen was isolated from wound cultures in 53 (31.7%) patients. 43.1% of SSIs (n = 72) were due to Gram-positive microorganisms, while 27.5% of cases (n = 46) involved Gram-negatives. Among Gram-positives, Staphylococci (n = 30, 17.9%) were the predominant microorganisms, while Klebsiellae (n = 16, 9.6%), Escherichia coli (n = 9, 5.4%), Pseudomonas aeruginosa (n = 7, 4.2%), and were the most prevalent among Gram-negatives. Colonization with VRE, MRSA, carbapenem resistant enteric bacteria on admission was detected in 9 (6.1%) cases. CONCLUSION To mitigate mortality following heart surgery, stringent infection control measures, preoperative screening, and effective surgical antisepsis are crucial. Timely detection of bloodstream infections and the clinical progression of the disease reflected by qSOFA score, and effective treatment are other essential components of SSI management.