Britney Benoit1, Ruth Martin-Misener1, Aaron Newman1, Margot Latimer1, Marsha Campbell-Yeo1
Canada
Background: While infant pain assessment has historically relied on behavioural pain scores, use of neurophysiological imaging methods is an emerging trend. However, to date, there is a lack of synthesis and evaluation of the neuroimaging technologies, data collection and analysis procedures, and study findings to allow recommendations for future work in the field.
Aim: To describe the neurophysiological methods that have been used to construct the scientific knowledge base in the field of infant acute pain assessment.
Methods: A systematic search of key electronic databases (CINAHL, PubMed, PsycINFO, EMBASE) was conducted from database inception to October 2015. The search strategy included key terms for infant, acute pain, pain response, and neurophysiological imaging methods. Of the 2411 abstracts screened, 19 articles were retained and data on study methodology and results were extracted.
Results: Of the included studies, nine utilized near infrared spectroscopy (NIRS), two utilized functional magnetic resonance imaging (fMRI), and eight utilized electroencephalography (EEG) as the primary outcome. There was variability in research designs and procedures in those studies utilizing NIRS, whereas studies utilizing EEG and fMRI reported consistent methods across studies. Of the eight EEG studies, six reported event-related potentials (ERPs) as the primary outcome. All of the ERP studies identified a distinct nociceptive-specific potential, which was found to be stimulus intensity dependent, independent of sleep state, and present in preterm and full term infants.
Conclusion: Of the neurophysiological methods used to date, ERPs appear to be the most consistently described indicator of infant nociception. While additional research is needed, ERPs may be a valuable neurophysiological indicator to supplement behavioural pain tools for use in clinical research to advance our understanding of infant pain responding.
