Relations Between Behavioral and Cardiac Autonomic Reactivity to Acute Pain in Preterm Neonates

Abstract

Objective-The purpose of this study was to assess relations and concordance between behavioral and physiologic reactivity to pain in preterm neonates at 32 weeks postconceptional age as a function of gestational age at birth. Setting-Level III neonatal intensive care unit.Design/Patients-The study group comprised 136 preterm neonates (mean [range] birthweight, 1,020 g [445-1,500 g]; gestational age at birth, 28 weeks [23-32 weeks]) separated into three groups according to gestational age at birth as follows: 23 to 26 weeks (n = 48), 27 to 29 weeks (n = 52), and 30 to 32 weeks (n = 36).Outcome Measures-Reactivity to routine blood collection at 32 weeks postconceptional age was assessed using bedside-recorded behavioral and autonomic measures. Coders who were blinded to the study design scored behavioral responses (facial activity using the Neonatal Facial Coding System, sleep/waking state, and finger splay). Autonomic reactivity was assessed by change in heart rate and spectral analysis of heart rate variability (change in low-frequency and high-frequency power, and the ratio of low-frequency to high-frequency power during blood collection).Results-Facial activity and state correlated moderately with change in heart rate across gestational age groups (r = 0.41-0.62). Facial activity and state did not correlate significantly with change in low-frequency and high-frequency power, or the ratio of low-frequency to high-frequency power (r = 0.00-0.31). Finger splay did not correlate with any autonomic recording (r = 0.03-0.41). Concordance between established biobehavioral measures of pain revealed individual differences. Although some neonates showed high behavioral but low physiologic reactivity, other neonates displayed the opposite reaction; however, the majority displayed concordant reactions. Conclusions-The study findings confirm the value of measuring domains independently, especially in neonates born at a very young gestational age. Multidimensional assessment of pain using both biological and behavioral measures is essential because different parameters can potentially yield different information. 3-5 This assessment can be approached in two ways. Composite scales additively combine elements of physiologic and behavioral responses, providing a summary score. Alternatively, multiple sources of response are recorded, but are not combined into a single score. The purpose of this study was to examine the relations between behavioral and physiologic reactivity to further understand the development of pain-response systems. For the purpose of research, several univariate measures were studied. KeywordsFew studies have reported relations between behavioral and physiologic responses during painful procedures. Relations between responses may differ across GA and vary with background experience. 5 In some studies with neonates of young postconceptional age (PCA) and with neonates born close to term, facial activity and measures of heart rate were moderately related. Among neonates with a mean PCA of 28-29 week...

Skin conductance as a marker of pain in infants of different gestational age

“…However, term infants are not used to dealing with painful stimuli. Their behaviour is just more organized 18,19 . Much work has been done relating to pain assessment in preterm infants.…”

Initial validation of the Behavioral Indicators of Infant Pain (BIIP)

“…Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. and physiological components, dissociations between behavioral and physiological pain responses are common (Barr, 1998;Morison et al, 2001). Furthermore, facial actions are the relatively most specific behavioral pain indicators in preterm infants, yet these responses may be dampened.…”

“…In order to provide appropriate pain management in this population, accurate assessment of pain is necessary (Anand et al, 2005), yet complex because we are limited to indirect measures of pain responses. And although infant pain responses have both behavioral and physiological components, dissociations between behavioral and physiological pain responses are common (Barr, 1998;Morison et al, 2001). Furthermore, facial actions are the relatively most specific behavioral pain indicators in preterm infants, yet these responses may be dampened.…”

Specific Newborn Individualized Developmental Care and Assessment Program Movements Are Associated With Acute Pain in Preterm Infants in the Neonatal Intensive Care Unit

“…Third, no physiologic or behavioral threshold specifically marks the presence of pain. Finally, although using a single pain index is easier for clinicians, the physiologic and behavioral responses of preterm infants to painful stimuli are often dissociated 15 ; therefore, reliance on current pain indices may not capture the range of responses in this population. 16 Currently, changes in facial activity, shifts in infant sleep/waking state, and physiologic indices of heart rate are the most promising biobehavioral pain indicators in preterm infants.…”