Risk factors for nosocomial infection in a neonatal intensive care unit.

Objective: To determine risk factors for nosocomial infection in a neonatal intensive care unit (NICU).

Design: A prospective, open cohort study.

Setting: A 22-bed NICU.

Patients: Neonates admitted to a single NICU during 1994-1998 were included in the study. Outcome variables included central venous catheter (CVC)-associated primary bloodstream infection (BSI), non-CVC-associated primary BSI, pneumonia, and overall nosocomial infection. Independent variables included birth weight, use of mechanical ventilation (MV), duration of MV, use of a CVC, duration of CVC use, duration of NICU stay, gestational age, congenital malformation, maximum (ie, worst) base excess, and maximum and minimum fraction of inspired oxygen (FIO(2)) for maintaining appropriate blood saturation levels during the first 12 hours after NICU admission.

Results: A total of 1051 neonates were admitted to the NICU. Overall, 358 NIs were diagnosed. Non-CVC-associated primary BSI was the most frequent nosocomial infection (in 195 neonates [54.5%]), followed by pneumonia (46 [12.8%]), and CVC-associated primary BSI (35 [9.8%]). The mortality rate was 16%. In the final logistic regression model, the following 5 risk factors were found to be predictive of nosocomial infection development: use of MV, longer duration of MV, longer duration of CVC use, longer duration of NICU stay, and low maximum appropriate Fio(2).

Conclusion: Invasive device use and duration of use continue to greatly influence the development of nosocomial infection in NICUs. In our cohort, birth weight showed no influence on the development of nosocomial infection. Low maximum Fio(2) influenced the occurrence of overall nosocomial infection.