Risk factors of nosocomial infection after cardiac surgery in children with congenital heart disease

Background: The aim of our study was to analyze the risk factors of nosocomial infection after cardiac surgery in children with congenital heart disease (CHD). Methods: We performed a retrospective cohort study, and children with CHD who underwent open-heart surgeries at Shanghai Children’s Medical Center from January 1, 2012 to December 31, 2018 were included. The baseline characteristics of these patients of different ages, including neonates (0-1 months old), infants (1-12 months old) and children (1-10 years old), were analyzed, and the association of risk factors with postoperative nosocomial infection were assessed. Results: A total of 11651 subjects were included in the study. The overall nosocomial infection rate was 10.8%. Nosocomial infection rates in neonates, infants, and children with congenital heart disease were 32.9%, 15.4%, and 5.2%, respectively. Multivariate logistic regression analysis found age (OR 0798, 95%CI: 0.769-0.829; P<0.001), STS risk grade (OR 1.267, 95%CI: 1.159-1.385; P<0.001), body mass index (BMI) <5th percentile (OR 1.295, 95%CI: 1.023-1.639; P=0.032), BMI ＞95th percentile (OR 0.792, 95%CI: 0.647-0.969; P=0.023), cardiopulmonary bypass (CPB) time (OR 1.008, 95%CI: 1.003-1.012; P<0.001) and aortic clamping time （OR 1.009, 1.002-1.015; P = 0.008）were significantly associated with nosocomial infection in CHD infants. After adjusted for confounding factors, we found STS risk grade (OR 1.38, 95%CI: 1.167-1.633; P<0.001), BMI<5th percentile (OR 1.934, 95%CI: 1.377-2.715; P<0.001), CPB time (OR 1.018, 95%CI: 1.015-1.022; P<0.001), lymphocyte/WBC ratio﹤cut off value (OR 3.818, 95%CI: 1.529-9.533; P=0.004) and AST＞cut off value (OR 1.546, 95%CI: 1.119-2.136; P=0.008) were significantly associated with nosocomial infection in CHD children. Conclusion: Our study suggested STS risk grade, BMI, CPB duration, low lymphocyte/WBC or high neutrophil/WBC ratio were independently associated with nosocomial infection in CHD infant and children after cardiac surgery.