Risk factors for surgical site infection in pediatric cardiac surgery patients undergoing delayed sternal closure

Objectives: To determine the incidence of surgical site infections (SSIs) in congenital heart surgery (CHS) patients undergoing delayed sternal closure (DSC) and to evaluate risk factors for SSI. Methods: A nested case-control study was performed within a cohort of CHS patients undergoing DSC at our institution between 2005 and 2009. Cases met 2008 Centers for Disease Control and Prevention criteria for SSI; control subjects were matched based on year of surgery. Uni- and multivariate logistic regressions were performed to identify SSI risk factors. Results: Of 375 patients who underwent DSC, 43 (11%) developed an SSI. The analysis included 172 patients (43 cases, 129 controls); 118 (69%) were neonates, 80 (47%) had undergone Norwood procedure, and 150 (87%) had DSC initiated in the operating room. Case and control subjects were similar based on pre- and intraoperative characteristics. Duration of mechanical ventilation, intensive care unit and hospital length of stay, and mortality were significantly greater in patients with an SSI. Multiple periods of DSC, longer duration of DSC, greater dependence on parenteral nutrition, and extracorporeal membrane oxygenation were significantly associated with SSI in univariate analyses. Multivariate analysis demonstrated that multiple periods of DSC (adjusted odds ratio, 5.9; 95% confidence interval, 1.7-20.1) and extracorporeal membrane oxygenation (adjusted odds ratio, 2.9; 95% confidence interval, 1.1-7.6) remained independent risk factors for SSI. Conclusions: For CHS patients undergoing DSC, extracorporeal membrane oxygenation and multiple periods of DSC are independent risk factors for SSI. New strategies for prevention and prophylaxis of SSI may be indicated for these high-risk patients who have worse outcomes and greater health care resource utilization.