Effect of non-sucrose sweet tasting solution on neonatal heel prick responses. Effects of chewing gum on responses to routine painful procedures in children. Intra-oral administration of sweet-tasting substances and infants' crying response to immunization: a randomized, placebo-controlled trial.
A substance commercially described as 'sugar free,' used as a sweetener for paracetamol suspension, was evaluated on measures of neonatal pain. Sixty infants were randomly allocated to receive one of four solutions before heel stab blood sampling: sterile water (placebo); 25 or 50% sucrose (weight/volume); and the commercial sweet-tasting solution. There was a significant reduction in crying time and pain score 3 minutes after the painful stimulus in all groups compared with the controls. It is concluded that this sweet-tasting solution has analgesic effects as potent as those of concentrated sucrose solutions. In infants, sweet taste and sucking on a pacifier both have analgesic effects. Animal studies suggest that sweet taste may involve opioids, while rhythmic oral movements, as with a pacifier, increase the release of serotonin, which is involved in the gating of nociceptive afferents. The present study was designed to see if these effects produce an analgesic effect in children. Two studies were performed, during blood draws in a pediatric test center in 7- to 12-year-old children, and during vaccination at school in 9- to 11-year-old children. Using unsweetened or sweetened chewing gum, there were four groups: control, sweet, chew, and sweet plus chew. Overall, there was no effect of either sweet taste or chewing on pain responses. However, in boys sweet taste tended to increase pain ratings, but only in conjunction with chewing, while in girls sweet taste tended to decrease pain ratings in conjunction with chewing and increased them in the absence of chewing. Ratings of pain intensity and affective state were correlated. Affective state before the painful stimulus was related to pain response in the girls and in the boys in the test center, but not in the schools. In the schools, the presence of peers may have influenced the ratings. The analgesic effects of four solutions administered intra-orally (25 and 50% sucrose solutions, hydrogenated glucose, and a sterile water placebo) were tested in groups of babies receiving routine DTP (diphtheria, tetanus, and pertussis) and HIB (Haemophilus influenzae type B) injections at the first, second, or third immunization. The duration of the baby's cry during 3 min following DTP and HIB injections was measured as main outcome. For all three immunization groups, the babies receiving the placebo generally spent most time crying. For both the DTP and HIB injections, the difference between 50% sucrose and placebo was most evident in the group receiving the 3rd immunization. Intra-oral administration of the 50% sucrose solution, compared to placebo, appeared to reduce the cry response to painful experiences in babies beyond the neonatal period.
                Copyright 2002 S. Karger AG, Basel
Based on these four studies, two of which were subgroups of small numbers of eligible toddlers from larger studies, there is insufficient evidence of the analgesic effects of sweet tasting solutions or substances during acute painful procedures in children over one year of age. Further well-conducted RCTs are warranted in this population.