Cortical Pain Response of Newborn Infants to Venepuncture

OBJECTIVE:Sucrose administration and breastfeeding decrease behavioral expressions of pain in neonates. However, recent studies indicated that there is a persistent cortical response with sucrose. This study compared the efficacy of sucrose administration versus breastfeeding to decrease cortical responses to pain during venepuncture.PATIENTS AND METHODS:A randomized, prospective, controlled trial was conducted in a tertiary level maternity ward. Healthy, 3-day-old term neonates, undergoing venepuncture for neonatal screening, were randomly assigned to receive sucrose solution or be breastfed before venepuncture. Variations in the total hemoglobin concentration [HbT] in the contralateral somatosensory cortex were assessed with near infrared spectroscopy. The Neonatal Facial Coding System (NFCS) was used to assess reactions.RESULTS:There were 114 term neonates included, with 102 included for the primary outcome (breastfed group: 48; sucrose group: 54). Similar maximum increases in [HbT] were observed in both groups (mean±SD: sucrose group: 31.2±58.1 μmol/L; breastfed group: 38.9±61.4 μmol/L; P=0.70). Breastfed neonates presented more behavioral expressions that indicated pain compared with sucrose-administered neonates (46.8% vs. 26.8% of NFCS ≥1, P=0.04). The maximum increase in [HbT] was persistent, although newborn infants who did not express behavioral signs of pain had lower concentrations than neonates who did (mean±SD: 21.2±29.1 vs. 60.0±89.8 μmol/L, P<0.01).DISCUSSION:There was no difference in the cortical responses to pain during venepuncture in newborn infants who were administered sucrose versus those who were breastfed.