ELECTRODERMAL ACTIVITY AND NEONATAL PAIN ASSESSMENT

Abstract

Endosomatic electrodormal activity is the electrical activity of the skin when no external current is applied. It is referred to as skin potential, and is measured by the application of surface electrodes. In general it is believed that skin potential gives a measure of arousal, and will change in response to autonomic nervous system activity. In order to assess the use of skin potential as an index of pain in the newborn, we have measured skin potentials in 29 healthy torm and 11 healthy preterm neonates (modian (range) GA 39 (37-42) and 34 (32-36) weeks respectively) and in 19 preterm neonates receiving intensive care (median GA 26 weeks, range 24-34). Changes in background skin potential level (SPL) and the occurrence of skin potential rosponses (SPR) to both noxious stimulus (heel stab blood test) and non-noxious stimuli, such as touch have been accessed in 79 recordings. SPRs were recorded in 22% sick preterm infants and 45% of healthy infants in response to noxious stimuli. Infants were more likely to show SPR to a non-noxlous stimuli than to a noxious stimulus. Spontaneous SPRs were also seen in number of infants. Endosomatic electrodermal activity is not a suitable means of pain assessment in the newborn infant so neither skin potential responses nor changes in the skin potential level can be used to differentiate noxious from non-noxious stimuli.