Biomarkers of pain: physiological indices of pain reactivity in infants and children
Biomarkers are common in all areas of clinical work, health research, and are critical indicators of diseases and physiological states. Preferably, a biomarker should be non-invasively accessible, low in cost, highly specific, sensitive, and easy to interpret. Due to the complexity of the pain system, no unidimensional reliable biomarker for pain has been identified to date. Developmental changes and delayed maturation of the involved physiological systems add another layer of complexity to the use of biomarkers in the paediatric population. Nevertheless, readily available and reliable biomarkers of pain would greatly enhance timely and appropriate treatment of pain, especially in infants and verbally or cognitively challenged children. This chapter examines currently available markers, their use, and limitations.