Early pain in preterm infants - A model of long-term effects

Experience shapes the developing brain and can reprogram stress systems [1,2]. Therefore, the developmentally "unexpected" stimulation of prolonged repetitive pain and stress induced by invasive procedures and their spin-off effects, as part of life-saving neonatal intensive medical care, continues to be a major concern. There are several recent reviews of potential long-term effects of early pain on the developing. infant [3-6] and advances in understanding the developmental neurobiology of pain [7]. In this article, a model for conceptualizing long-term effects of pain on human neonates is presented, and emerging evidence in support of this model is examined. Although there is still very limited empirical data in humans specifically related to long-term effects of early physical pain, concerns are prevalent that among vulnerable prematurely born infants, repeated and prolonged pain exposure may alter subsequent development of pain systems, as well as affect long-term neurodevelopmental and social-emotional functioning. These concerns are backed by multiple lines, of evidence that stress systems are particularly vulnerable to permanent change, reflecting early plasticity of the central nervous system (CNS). The neurobiologic substrate for pain experience is inherently different in infants born very prematurely who undergo hospitalization during a period of the most rapid brain development. As the most vulnerable infants, this article focuses on potential effects of repetitive pain in preterm infants.