Effects of white noise on procedural pain-related cortical response and pain score in neonates: A randomized controlled trial

To evaluate the effects of white noise on pain-related cortical response, pain score, and behavioral and physiological parameters in neonates with procedural pain. A double-blind, randomized controlled trial was conducted. Sixty-six neonates from the Neonatal Intensive Care Unit in a university-affiliated general hospital were randomly assigned to listen to white noise at 50 dB (experimental group) or 0 dB (control group) 2 min before radial artery blood sampling and continued until 5 min after needle withdrawal. Pain-related cortical response was measured by regional cerebral oxygen saturation (rScO2) monitored with near-infrared spectroscopy, facial expressions and physiological parameters recorded by two video cameras. Two assessors scored the Premature Infant Pain Profile-Revised (PIPP-R) independently when viewing the videos. Primary outcomes were pain score and rScO2 during arterial puncture and 5 min after needle withdrawal. Secondary outcomes were pulse oximetric oxygen saturation (SpO2) and heart rate (HR) during arterial puncture. Sixty neonates (experimental group, n = 29; control group, n = 31) were included in the final analysis. The maximum PIPP-R score in the experimental and control groups was 12.00 (9.50, 13.00), 12.50 (10.50, 13.75), respectively (median difference − 0.5, 95% CI −2.0 to 0.5), and minimum rScO2 was 61.22 ± 3.07%, 61.32 ± 2.79%, respectively (mean difference − 0.325, 95% CI −1.382 to 0.732), without significant differences. During arterial puncture, the mean rScO2, HR, and SpO2 did not differ between groups. After needle withdrawal, the level of rScO2 and PIPP-R score, and facial expression returned to baseline faster in the experimental group without statistical significance. The white noise intervention did not show beneficial effects on pain-related cortical response as well as pain score, behavioral and physiological parameters in neonates with procedural pain.