Epidemiology of antibiotic use in a neonatal intensive care unit

To determine the incidence and pattern of antibiotic use in a neonatal intensive care unit (NICU).

Prospective study of a one-month NICU cohort. Investigators visited each subject, checking nursing notes, antibiotic flow sheets, and laboratory data at each daily visit.

The NICU at Yale-New Haven Hospital, New Haven, Connecticut; a regional care, level 3 unit in a tertiary care medical center.

All infants admitted to the NICU for one month (n = 63) who resided in the unit for > or = 24 hours.

75% of the infants had antibiotic treatment begun in the first 48 hours of life. The highest rate of antibiotic treatment starts was in premature infants with birthweight less than 1,500 g, 92% of whom received antibiotics in the first 48 hours. In the subsequent days of life the incidence of starting antibiotic treatment was low and sporadic and the prevalence of antibiotic treatment by day of life showed a sharp decline between the third and fourth days of life. Five cross-sectional studies in the nursery showed point-prevalence rates of antibiotic use to be 27% to 43% of the whole NICU population, highest in the intensive care sector of the unit and in those < 72 hours of age.

The high incidence of antibiotic starts in this NICU was largely the result of almost universal treatment of premature infants beginning on the first day of life. The risk of infection in these infants is quite low; more information is needed concerning how to distinguish infants who do not require treatment. This study provides comparison data for NICUs compiling data on incidence and prevalence of antibiotic use and developing programs to limit antibiotic use.