The newborn infant parasympathetic evaluation in pediatric and neonatology: a literature review

Purpose The Newborn Infant Parasympathetic Evaluation (NIPE) is a heart rate variability-based technology for assessing pain and comfort in neonates and infants under 2-years-old. This review aims to investigate the clinical utility of the NIPE. Methods Two investigators screened Pubmed/Medline and Google Scholar for relevant studies, independently. One investigator extracted data, which were reviewed by a second investigator. Results The NIPE was used during/after painful stimuli (6 studies), in the context of general anaesthesia (2 studies), and for comfort assessment (6 studies). A) Evaluation of procedural pain/distress: 2 studies reported that the mean-NIPE could be used for reliable monitoring of prolonged pain, and one study reported the association between instant-NIPE and pain after a stimulus but the instant-NIPE represents the NIPE average over 3 min. Two studies found no correlation between the NIPE and comfort behavior/pain scales, but they mainly differed in patients’ gestational age and evaluation methodology. B) There are only 2 studies for the evaluation of nociception during surgery under general anaesthesia with contradictory results. C) Studies assessing neonates’ comfort reported increased NIPE scores during skin-to-skin contact and during facilitated tucking associated with a human voice. No effect on NIPE scores of facilitated tucking during echocardiography was reported in preterm infants. One study reported significantly different NIPE scores with 2 surfactant therapy protocols. Overall, study populations were small and heterogeneous. Conclusion The results regarding NIPE’s performances differ between studies. Given the limited number of studies and the heterogeneous outcomes, more studies are required to confirm the NIPE usefulness in the different clinical settings.