Sugar Does Not Relieve Newborn Pain

A physician I was interviewing recently informed me that when he performs circumcision surgery upon a newborn baby (96% undergoing prepuce amputation do not receive anesthesia for the procedure in the United States), "I give him a pacifier dipped in a solution of 25% sucrose, which helps to soothe him during surgery." Another OB/GYN who also uses sugar-dipped pacifiers during genital cutting said, "We don't use anesthesia here because that is just more mucking, and babies don't like being mucked with." According to the following news report by the UCL Research Department of Neuroscience, Physiology and Pharmacology (NPP), however, this sugar method of pseudo 'pain relief' is as bogus as we assumed it to be.


In 2001, recommendations were published, that suggested oral sucrose (sugar) be given to newborns to help relieve pain from invasive procedures (including circumcision surgery).

But a new study led by the UCL Research Department of Neuroscience, Physiology & Pharmacology (NPP) and published today in The Lancet, shows that giving sugar to newborn babies as a form of pain relief does not work.

Instead, sucrose changes the facial expressions of some babies giving the impression that pain is being relieved. The finding could lead to future changes in healthcare policy as oral sucrose is frequently given to relieve procedural pain in newborn babies who must undergo invasive procedures, such as taking blood from a vein or heel lances.

The trial, funded by the Medical Research Council, studied 59 newborn, healthy babies at University College Hospital and found that activity in the pain areas of the brain did not differ regardless of whether they were given sucrose for pain relief. There was little difference between the infants’ leg reflex reactions either, which also indicates discomfort.

Scientists measured pain activity in the brain and spinal cord before and after babies had undergone a routine heel lance – a standard procedure used to collect blood samples from babies. Half the babies were given a sucrose solution prior to the lance, as per the standard procedure, and the remainder were given sterilized water. Brain activity was measured using neonatal electroencephalography (EEG) and spinal cord pain reflex was recorded with electromyography (EMG).

Dr Rebeccah Slater (UCL Research Department of Neuroscience, Physiology & Pharmacology), who led the study, reports, “Our findings indicate that sucrose is not an effective pain relief drug. This is especially important in view of the increasing evidence that pain causes short and long-term adverse effects of infant neurodevelopment. While we remain unsure of the impact pain has, we suggest that it is not used routinely to relieve pain in infants without further investigation.”

Professor Chris Kennard, chair of the MRC’s Neuroscience and Mental Health funding board says, “This trial has significant implications for healthcare policy and is a first class example of where MRC research is helping bring scientific discoveries from laboratory bench to patient bedside more quickly. With uncertainty around the role that pain plays in a baby’s neurodevelopment, this research is a vital tool for informing healthcare decision makers. Scientific advancements like these would not be possible without the support of medical research volunteers, and families and scientists remain indebted to the huge contribution from members of the public.”

The paper, "Oral sucrose as an analgesic drug for procedural pain in newborn infants: a randomised controlled trial" is published in The Lancet today.

Citation:

Slater, Rebeccah, et al. "Oral sucrose as an analgesic drug for procedural pain in newborn infants: a randomised controlled trial." The Lancet, 10.1016/S0140-6736 (10)61303-7.

Background
Many infants admitted to hospital undergo repeated invasive procedures. Oral sucrose is frequently given to relieve procedural pain in neonates on the basis of its effect on behavioural and physiological pain scores. We assessed whether sucrose administration reduces pain-specific brain and spinal cord activity after an acute noxious procedure in newborn infants.

Methods
In this double-blind, randomised controlled trial, 59 newborn infants at University College Hospital (London, UK) were randomly assigned to receive 0·5 mL 24% sucrose solution or 0·5 mL sterile water 2 min before undergoing a clinically required heel lance. Randomisation was by a computer-generated randomisation code, and researchers, clinicians, participants, and parents were masked to the identity of the solutions. The primary outcome was pain-specific brain activity evoked by one time-locked heel lance, recorded with electroencephalography and identified by principal component analysis. Secondary measures were baseline behavioural and physiological measures, observational pain scores (PIPP), and spinal nociceptive reflex withdrawal activity. Data were analysed per protocol. This study is registered, number ISRCTN78390996.

Findings
29 infants were assigned to receive sucrose and 30 to sterilised water; 20 and 24 infants, respectively, were included in the analysis of the primary outcome measure. Nociceptive brain activity after the noxious heel lance did not differ significantly between infants who received sucrose and those who received sterile water (sucrose: mean 0·10, 95% CI 0·04—0·16; sterile water: mean 0·08, 0·04—0·12; p=0·46). No significant difference was recorded between the sucrose and sterile water groups in the magnitude or latency of the spinal nociceptive reflex withdrawal recorded from the biceps femoris of the stimulated leg. The PIPP score was significantly lower in infants given sucrose than in those given sterile water (mean 5·8, 95% CI 3·7—7·8 vs 8·5, 7·3—9·8; p=0·02) and significantly more infants had no change in facial expression after sucrose administration (seven of 20 [35%] vs none of 24; p<0·0001).>