Editor—Currently, most minor procedures in neonates are performed with little or no analgesia. We found that pacifiers can effectively relieve pain and that the analgesic effect is synergetic with sucrose. To our knowledge, this latter effect, which has practical implications, had not been reported before our study. Recently, Blass and Watt reported the same effect.5-1
Campbell wonders why we did not include breast milk or suckling at the breast before and immediately after painful procedures. Our study included six groups, and it would have been difficult to add more—firstly, because of the masking constraints imposed by a randomised double blind study, and, secondly, because we aimed to compare the analgesic effects of non-nutritive sucking with those of sugary solutions. A single study cannot answer several questions at once.
Analgesia induced by milk has been shown in newborn infants.5-2 This effect was not related to lactose and was modest compared with that of sugar. We do not agree with Campbell when she states that pacifiers and sugar solutions given for analgesic purposes are given unnecessarily. We adhere to the “ten steps to successful breastfeeding” and consider that, with regard to step 6, relief of neonatal pain with pacifiers and sugar solutions is medically indicated. We do not think that occasional use of pacifiers or small volumes of sterile glucose or sucrose solutions for a painful procedure should be regarded as equivalent to frequent or routine use.
Blomstrand suggests that the less varied response to venepuncture in infants treated with a pacifier may be due to these infants' inability to express a range of facial expressions during the treatment. This hypothesis can be rejected for at least two reasons. Firstly, when one evaluates facial expressions on the rating scale that we used the modification of only one of eye squeeze, brow bulge, or nasolabial furrow is enough to determine the intensity of this item. Eye squeeze and brow bulge are not incompatible with sucking. Secondly, infants who suck a pacifier make several pauses between sucking bursts, which gives them the opportunity to express grimacing.
Morris asks if evidence is needed to justify cuddling a baby in pain. Obviously not. However, studies that determine the efficacy of behavioural interventions in preventing pain in neonates are welcome for, as Choonara states,5-3 they can encourage health professionals to modify their behaviour. Morris's hypothesis offering instinct and conditioning to explain the mechanism by which pacifiers induce analgesia is interesting. Blass and Watt have suggested that antinociception and pain blockades induced by orogustatory and orotactile mechanisms are likely to be occurring at the level of the dorsal horn of the spinal cord.5-1
Rogers's concern about the difference between analgesia and reduced behavioural response to pain is theoretically valid. As he states, pain has been defined as a subjective experience. This definition has led to many advances, but it challenges our understanding of pain because it does not apply to living organisms that are incapable of self report. This includes neonates and older infants and many adult patients.5-4
The biological and behavioural reactions to pain are evident in term and preterm neonates. The fact that neonates' expression of unpleasantness does not fit within the strict definition of pain contributes to the failure to recognise and aggressively treat pain in children.5-4 Increasing evidence supports the specificity of facial expressions as a manifestation of pain in neonates. As we stated in our paper, we assumed that the more pronounced the facial expressions, limb movements, and vocal expressions the greater the pain in the neonates.
Rashid makes an important point. Endotracheal intubation is a powerful noxious stimulus with potential adverse effects. Although premedication is mandatory for endotracheal intubation in adults, most neonatal units do not sedate neonates before intubating them. Recently, Bhutada et al showed that the heart rate and blood pressure of neonates who are premedicated with thiopental before intubation remain nearer to baseline values than do those of similar infants not given premedication.5-5
References
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