Effects of the neonatal intensive care unit environment on preterm infant oral feeding.

Objective: To examine the effect of neonatal intensive care unit environmental characteristics (perceived levels of light and sound, and time of day) in open unit wards and single-family rooms (SFRs) on oral feeding outcomes in preterm infants.

Design: Data were collected at each scheduled oral feeding for 87 preterm infants from the first oral feeding until discharge. Data included the prescribed volume of feeding and the volume consumed, the infant's level of wakefulness before feeding, and the nurse's perception of light and sound.

Results: Data were collected on 5111 feedings in the ward unit and 5802 in the SFR unit from feedings involving 87 preterm infants. Light and sound were rated significantly lower in the SFR (χ² = 139 and 1654.8, respectively). Feeding times of 9 am, 12 noon, and 3 pm were associated with the highest perceived levels of light and sound, regardless of unit design (P < 0.0001). Moderate light levels and feeding times of 12, 3, and 6 am were associated with improved feeding outcomes. Infants consumed a greater proportion of their prescribed feeding volume when fed in the open ward and when awake before feeding.

Conclusion: Further study on the clinical effects of unit design is needed, as is study on the effects of environmental stimuli, so that interventions can be appropriately developed and tailored for infants needing the most support for optimal development.