Pain Behavioural Response to Acoustic and Light Environmental Changes in Very Preterm Infants.

Audrey Marchal,André Dufour,Pierre Kuhn,Meggane Melchior,Claire Zores,Pierrick Poisbeau

doi:10.3390/children8121081

Abstract

Noise and high light illumination in the neonatal intensive care unit (NICU) are recognized as stressors that could alter the well-being and development of vulnerable preterm infants. This prospective observational study evaluated the pain behaviours of very preterm infants (VPIs) to sound peaks (SPs) and light levels variations (LLVs) in the NICU. We measured spontaneously occurring SPs and LLVs in the incubators of 26 VPIs over 10 h. Their behavioural responses were analysed through video recordings using the “Douleur Aigue du Nouveau-né” (DAN) scale. We compared the maximum DAN scores before and after environmental stimuli and the percentage of VPIs with a score ≥ 3 according to the type of stimuli. A total of 591 SPs and 278 LLVs were analysed. SPs of 5 to 15 dBA and LLVs significantly increased the maximum DAN scores compared to baseline. The occurrence of DAN scores ≥ 3 increased with both stressors, with a total of 16% of SPs and 8% of LLVs leading to quantifiable pain behaviour. Altogether, this study shows that VPIs are sensitive to SPs and LLVs, with a slighter higher sensitivity to SPs. The mechanisms leading to pain behaviours induced by noise and light changes should be evaluated further in the context of VPIs brain development. Our results provide further arguments to optimize the NICU sensory environment of neonatal units and to adapt it to the expectations and sensory abilities of VPIs.

Highlights

Despite recent advances in neonatal care, about 40% of very preterm infants (VPIs), born before 32 weeks of gestational age, have neurodevelopmental sequelae in France and in high income countries [1,2,3,4]
To determine whether sound peaks (SPs) lead to pain behaviour according to the standard clinical criteria in VPIs, we evaluated the occurrence of du Nouveau-né” (DAN) scores ≥ 3 for all SPs
We observed a significant increase in maximal DAN scores, whatever the light level changes and the sleep state (Wilcoxon matched-pairs signed rank test, W = 253, p < 0.001; n = 23), from an average baseline DAN score of 0.48 (±0.47) to 1.04 (±0.56) after levels variations (LLVs)

Summary

Introduction

Despite recent advances in neonatal care, about 40% of very preterm infants (VPIs), born before 32 weeks of gestational age, have neurodevelopmental sequelae in France and in high income countries [1,2,3,4]. VPIs are exposed to numerous and repeated painful stimuli [6,7], which have been shown to have consequences later in life [8,9]. Painful stimuli during caring procedures have been shown to affect brain growth and functions in VPIs [9,10,11]. The sensory systems of the newborn infants, still immature at birth, are among the first to develop and are functional during the last trimester of pregnancy, and VPIs are well equipped to react to the neonatal intensive care unit (NICU) environment [4,5]

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Results

Discussion

Conclusion