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

Accurate pain assessment in preterm infants in the neonatal intensive care unit (NICU) is complex. Infants who are born at early gestational ages (GA), and who have had greater early pain exposure, have dampened facial responses which may lead to under-treatment. Since behavioral and physiological responses to pain in infants are often dissociated, using multidimensional scales which combine these indicators into a single score may limit our ability to determine the effects of interventions on each system. Our aim was to design a unidimensional scale which would combine the relatively most specific, individual, behavioral indicators for assessing acute pain in this population. The Behavioral Indicators of Infant Pain (BIIP) combines sleep/wake states, 5 facial actions and 2 hand actions. Ninety-two infants born between 23 and 32 weeks GA were assessed during 3, 1 min Phases of blood collection. Outcome measures included changes in BIIP and in Neonatal Infant Pain Scale (NIPS) scores coded in real time from continuous bedside video recordings; changes in heart rate (HR) were obtained using custom physiological processing software. Scores on the BIIP changed significantly across Phases of blood collection (p<0.01). Internal consistency (0.82) and inter-rater reliability (0.80-0.92) were high. Correlations between the BIIP and NIPS were modest (r=0.64, p<0.01) as were correlations between the BIIP and mean heart rate (r=0.45, p<0.01). In this initial study, the BIIP has been shown to be a reliable, valid scale for assessing acute pain in preterm infants in the NICU.