Empirical antibiotic treatment and the risk of necrotizing enterocolitis and death in very low birth weight neonates

BACKGROUND AND OBJECTIVES: Antibiotics are one of the most overused drugs in the neonatal unit. Our objective was to assess associations between the duration of the initial antibiotic course and subsequent necrotizing enterocolitis (NEC) and/or death in very low birth weight (VLBW) neonates with sterile initial postnatal culture results. DESIGN AND SETTING: A retrospective cohort analysis of VLBW neonates admitted to a tertiary center during the period from 1 January 2008 to 31 December 2009. PATIENTS AND METHODS: The study included VLBW neonates who had been inborn and admitted to the neonatal intensive care unit within the first 24 hours after birth. We used descriptive statistics to characterize the study population, and multivariate analyses to evaluate associations between therapy duration, prolonged empirical therapy, and subsequent NEC and/or death. RESULTS: Of 328 VLBW neonates admitted to our center, 207 (63%) survived >5 days and received initial empirical antibiotic treatment for >= 5 clays. The median duration of initial empirical antibiotic therapy was 7 days (range 5-10 days). Those neonates were more likely to be of younger gestational age, lower birth weight, and to have lower Apgar scores (P<.001, .001 and .017, respectively). Each empirical treatment day was associated with increased odds of death (OR 1.45, CI 1.24-1.69), NEC (OR 1.32, CI 1.05-1.65), and the composite measure of NEC or death (OR 2.13, CI 1.55-2.93). CONCLUSION: The use of prolonged initial empirical antibiotic therapy in VLBW neonates with initial sterile culture results may be associated with an increased risk of NEC or death and should be used with caution.