Crossover trial of analgesic efficacy of glucose and pacifier in very preterm neonates during subcutaneous injections

Objective. Very preterm newborns undergo multiple invasive procedures. Nonpharmacological interventions are valuable alternatives for pain relief during minor procedures in neonates. Oral sucrose analgesia has been widely studied in term and preterm neonates during painful procedures. The analgesic effect of oral glucose in very preterm infants has not yet been reported. The objectives of this study were to assess the analgesic effect of orally administered glucose and to determine the synergetic analgesic effect of glucose and pacifiers during subcutaneous injections in very preterm neonates using a validated behavioral acute pain rating scale. Design. Two crossover trials. Setting. One neonatal intensive care unit in a community-based general hospital. Methods. A prospective study was conducted in 40 very preterm neonates. Each infant received 2 treatments in a crossover manner during 2 consecutive subcutaneous injections of erythropoietin. The first trial (25 infants) was intended to compare oral 30% glucose (0.3 mL) versus placebo (0.3 mL of sterile water); the second trial (15 infants) compared oral 30% glucose (0.3 mL) versus oral 30% glucose (0.3 mL) followed by sucking a pacifier. The primary outcome measure was the evaluation of pain induced by a subcutaneous injection of erythropoietin, using Douleur Aigue Nouveau-ne' scale (0 no pain, 10 maximum pain). Results. Twenty-four infants completed the study in the first trial and 15 in the second one. Mean (95% confidence interval [CI]) gestational age, birth weight, postnatal age, and weight at inclusion for neonates in the first and second trial were, respectively, 28.1 (95% CI: 27.3-29.0) and 29.1 (95% CI: 27.8-30.4) weeks, 1036 (95% CI: 944-1128) and 995 (95% CI: 848-1141) g, 26.4 (95% CI: 22.4-30.3) and 26 (95% CI: 22.0-29.9) days, and 1234 (95% CI: 1120-1348) and 1209 (95% CI: 1059-1359) g. In the first trial, median (interquartile) pain scores for placebo and 30% glucose, respectively, were 7 (2.5-9.75) and 4.5 (1-6). In the second trial, median (interquartile) pain scores for 30% glucose and for 30% glucose plus pacifier, respectively, were 4 (2-7) and 4 (1-6). Conclusions. A small dose of 0.3 mL of 30% oral glucose has an analgesic effect in very preterm neonates during subcutaneous injections. This effect is clinically evident because it can be detected by a behavioral pain rating scale. The synergetic analgesic effect of glucose plus sucking a pacifier is less obvious in very preterm neonates as opposed to what other studies have showed in full-term infants.