663 - Antibiotic utilization among newborns with congenital diaphragmatic hernia

To assess antibiotic utilization among a large cohort of newborns with CDH over a 10-year period.  

Design/Methods: Retrospective observational study including inborn newborns with CDH at a level IV referral center (free standing children’s hospital with special delivery unit) and associated level III birth center who underwent active care and survived to NICU admission, born 1/2013-11/2022 with available disposition. Median total days for all parenteral/enteral antibiotics during birth hospitalization until 1 year of age were determined, overall and for individual drugs. Four metrics were calculated overall and by year: 1) proportion with antibiotic start in first 72h; 2) proportion with antibiotic start after 72h among those surviving for 72h; 3) length of therapy [LOT = antibiotic yes/no each day] per 100 patient days; and 4) days of therapy [DOT = aggregate sum of antibiotic days accounting for >1 drug per day] per 100 patient days. Trends in metrics over time were assessed visually.

Results: Of 381 newborns with CDH, median length of stay was 56 days, 344/381 (90.3%) underwent repair during birth hospitalization, and 315 (82.7%) survived to discharge (Table 1). Overall, 370/381 (97.1%) received antibiotics for a median of 13 (5,31) days (Table 2), including 242/381 (63.5%) in the first 72 hours and 352/359 (98.1%) after 72 hours. Ampicillin (50.4%) and gentamicin (52.8%) were used most in first 72 hours and cefazolin (91.6%), vancomycin (67.7%), and cefepime (65.7%) were used most after 72 hours. Overall LOT and DOT were 30/100 and 45/100 patient days, respectively. There were no apparent changes in antibiotic utilization over time (Figure).

Conclusion(s): In this large cohort of newborns with CDH over a 10-year period, more than half received antibiotics in the first 72 hours and nearly all after 72 hours. The most common early antibiotics were in line with AAP recommendations for early-onset infection risk. The most common later antibiotics likely reflect peri-operative prophylaxis (cefazolin) and empiric broad spectrum treatment (vancomycin and cefepime). Antibiotic use among newborns with CDH, assessed using 4 metrics, did not change over time.