Nosocomial infections in pediatric cardiovascular surgery patients: a 4-year survey.

Objective: To determine the prevalence, characteristics, and risk factors for nosocomial infections (NIs) in children postcardiac surgery and hospitalized in a pediatric intensive care unit (PICU).
Design: Case control study.
Setting: PICU of a tertiary care university-affiliated medical center.
Patients and Controls: Between January 1, 1999 and December 31, 2002, 356 children underwent cardiac surgery and were admitted to the PICU (381 admissions). There were 146 episodes (91 patients) of NI according to the Centers for Disease Control and Prevention criteria. The control group (92 patients) was drawn as a random sample from admissions with no evidence of NI.
Measurements and Main Results: Data retrieved from medical records included demographic information, type of operation, complexity score, extrinsic risk factors (invasive devices, postoperative complications, etc.), specific pathogens, therapeutic interventions, and outcome. There were 146 episodes of NI during 381 admissions, yielding a nosocomial infection ratio of 38.3%, and a prevalence of PICU-acquired infection of 24.4% (93 admissions with NI out of a total of 381 admissions). The most common NI sites were the bloodstream and the lower respiratory tract (65.8% and 16.4%, respectively). The main causative organisms were Coagulase negative Staphylococcus, Klebsiella pneumonia, and Candida spp. (18.8%, 16.7%, and 15%, respectively). Multivariate analysis revealed the following risk factors for NI: age < 2 months, congenital malformations, post operative complications, and open-chest procedure. The crude mortality rate for patients with NI was 23.7%, compared with 2.2% for patients without NI (p < 0.001). Predictors for mortality in patients with NI were post operative complications, open-chest procedure, sepsis, and urinary tract infection.
Conclusions: Our results draw attention to the importance of NI and their influence on survival in pediatric patients undergoing cardiac surgery. Prevention and control measures may reduce these infections and subsequently reduce morbidity and mortality in this vulnerable population.