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

Abstract

Objectives: To evaluate the effects of white noise on pain-related cortical response, pain score, and behavioral and physiological parameters in neonates with procedural pain.

Methods: 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, and facial expressions and physiological parameters were 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, and duration of painful expressions. The study was registered at the Chinese Clinical Trial Registry (ChiCTR2200055571).

Results: 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 trends for rScO₂, PIPP-R score, and facial expression returning to baseline were different between the two groups without statistical significance.

Conclusion: 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.

Keywords: Facial expression; Intensive care units; Neonates; Premature infant pain profile-revised; Procedural pain; Radial artery; Regional cerebral oxygen saturation; White noise.

Fig. 1

The timeline of the procedure. rScO₂ = regional cerebral oxygen saturation. HR = heart rate. SpO₂ = pulse oximetric oxygen saturation.

Fig. 2

Flow diagram. mITT = modified intent-to-treat. NIRS = near-infrared spectroscopy.

Fig. 3

Graphical trend for the estimates of the PIPP-R score derived from the generalized linear mixed-effect model. The PIPP-R score was assessed every 30 s during the 5 min after the needle withdrawal, and the 10 assessment time points were labeled as T1 to T10, respectively. PIPP-R = premature infant pain profile.

Fig. 4

Graphical trend for the estimates of the rScO₂ derived from the generalized linear mixed-effect model. The rScO₂ was assessed every 30 s during the 5 min after the needle withdrawal, and the 10 assessment time points were labeled as T1 to T10, respectively. rScO₂ = regional cerebral oxygen saturation.