Due to many infants admitted to hospital undergo repeated invasive procedures, therefore, oral sucrose is frequently given to relieve procedural pain in neonates on the basis of its effect on behavioral and physiological pain scores.

However, in the recent double-blind randomized controlled trial study, the researchers accessed whether sucrose administration reduce pain-specific brain and spinal cord activity after an acute noxious procedure in newborn infants.

As the results, according to investigators, oral sucrose may not provide effective analgesia in neonates.

The study authors, Rebeccah Slater, PhD, from the University College London, UK, and colleagues, said, “Our data suggest that oral sucrose does not significantly affect activity in neonatal brain or spinal cord nociceptive circuits, and therefore might not be an effective analgesic drug.”

According to the researchers, the ability of sucrose to reduce clinical observational scores after noxious events in newborn infants should not be interpreted as pain relief.

The study involved 59 newborn infants at University College Hospital.
Based on a computer-generated randomization code, the infants were allocated to receive 0.5 mL 24% sucrose solution or 0.5 mL sterile water 2 minutes before undergoing a clinically necessary heel lance.
The investigators, clinicians, participants, and parents were blinded as to the identify of the solutions.
The endpoints of main study enpoints was electroencephalographically determined pain-specific brain activity evoked by 1 time-locked heel lance.
Secondary outcomes were baseline behavioral and phsyiological measures, observational pain scores, and spinal nociceptive reflex withdrawal activity.

The endpoint of main study for per protocol analysis included 20 of 29 infants randomly assigned to receive sucrose and 24 of 30 infants randomly assigned to receive sterilized water.
The group had no significant difference in nociceptive brain activity after the noxious heel lance. Similarly, the groups did not differ significantly in magnitude or latency of the spinal nociceptive reflex withdrawal recorded from the biceps femoris of the stimulated leg.

As the results, according to the researches, compared with infants given sterile water, those given sucrose had a significantly lower observational pain score. After sucrose administration, significantly more infants had no change in facial expression.

Despite several limitations in this study such as that it was a single-center trial with a small sample size, which may mean that the trial was not powered for observation of subtle effects that sucrose might have on central nervous system processing, the authors conclude, “Sucrose seem to blunt facial expression activity after painful procedures, but our data suggest that it does not reduce direct nociceptive activity in central sensory circuits, and therefore might not be an effective analgesic drug.”

They added that “the absence of evidence for an analgesic action of sucrose in this study, together with uncertainty over the long-term benefits of repeated sucrose administration, suggest that sucrose should not be used routinely for procedural pain in infants without further investigation.”

As accompanying commentator, Robert E. Lasky, PhD, from the University of Texas Medical School in Houston, and Wim van Drongelen, PhD, from the University of Chicago, Illinois, note that despite its limitations, this study adds “an important and innovative measurement to evaluating pain management in newborn babies.”

Dr. Lasky and Dr. Drongele write, “Slater and colleagues characterise the cortical evoked responses that they recorded as a more direct measure than other responses used to measure pain in newborn babies. But, it is the wellbeing of the infant that is the definitive outcome in determining the efficacy of medical interventions and not surrogate outcomes, regardless of how central they are hypothesised to be to the pain response in the newborn baby…until we better understand pain pathways and the short-term and long-term premature to conclude that sucrose might not be an effective analgesic for newborn babies.”