Sucrose is an effective analgesic for procedural pain in preterm infants. It has been hypothesized that its analgesic effects are mediated by the release of endogenous opioid neurotransmitters such as β-endorphin.
To determine whether intraoral administration of sucrose was associated with an increase in serum β-endorphin concentrations in preterm infants with a gestation period less than 29 weeks who were not exposed to a painful stimulus.
We performed a prospective open-label study in preterm infants admitted to 2 tertiary neonatal intensive care units. Each infant received a single dose of 30% sucrose intraorally during a 1- to 2-minute period. A blood sample was obtained using an indwelling arterial catheter to determine β-endorphin concentration immediately before and 2 to 5 minutes after the commencement of sucrose administration.
We enrolled 11 preterm infants with a mean ± SD gestational age of 27.2 ± 0.9 weeks and a mean ± SD birth weight of 1018 ± 238 g (1.02 ± 0.24 kg) at a mean ± SD postnatal age of 3.0 ± 2.5 days. The mean ± SD β-endorphin concentration before and after sucrose administration was 60.4 ± 30.5 pg/mL and 57.4 ± 22.4 pg/mL, respectively (P = .45). No adverse events were observed during the study procedures.
Intraoral administration of sucrose in preterm infants did not lead to an increase in serum β-endorphin concentrations at a point in time when the analgesic effects of sucrose were presumed to be present.