The effects of environmental noise and infant position on cerebral oxygenation.

Purpose: To assess how different infant positions and peak sound levels affected cerebral oxygen saturation over time.

Subjects: Twenty-four premature infants who were born less than 32 weeks' gestational age without congenital cardiac, neurologic, and gastrointestinal anomalies.

Design: Repeated-measures design with the first observation between 2 and 48 hours of life; once again between 49 and 96 hours of life; on day of life 7; and every 7 days thereafter until discharge home, transfer to another hospital, or 40 weeks postmenstrual age, whichever came first.

Methods: Continuous sound levels (decibels) were obtained and 2 infant positions were performed while measuring cerebral oxygen saturation during 40-minute observation periods.

Main Outcome Measures: Effect of peak sound and differences in infant position on cerebral oxygen saturation.

Results: Peak sound levels 5 dB above the average ambient sound level did not significantly change cerebral oxygen saturation values. Differences in cerebral oxygenation were significantly less when infants were changed from a supine, head midline position to a right lateral, 15° head elevation compared with a left lateral, 0° elevation position.

Conclusions: Aspects of the current neonatal intensive care unit environment do not appear to affect cerebral oxygen saturation.