The cold pressor test in children: Methodological aspects and the analgesic effect of intraoral sucrose

Abstract

To determine whether intraoral sucrose has analgesic-like effects in pre-pubertal children and to explore the utility of an ethical and viable laboratory test of nociceptive stimulation in this age group, 8–11-year-olds ( n = 42) underwent the cold pressor test (CPT) at 10°C on each of 2 successive days, while holding either 24% sucrose or water in their mouths. Outcome measures used were threshold (time at which the arm first started to hurt), tolerance (when children removed their arms because they could not stand it any more) and visual analogue scale (VAS) ratings of the intensity of sensation. To ensure validity of the data obtained in this age group, some responses were rejected according to established decision rules and blind to group assignment. Each measure produced interesting data but also had limitations. Threshold data that did not meet validity criteria occurred more frequently with younger children. Tolerance data was not available for a significant proportion (57%) of children, since they left their arms in the water for the maximum time allowed (4 min). This occurred more frequently on the second day of testing and with younger children. Inability to perform adequately on the VAS also occurred, but was not related to age. Holding sucrose in the mouth was associated with a significant 35% prolongation of the children's threshold times relative to water, but there was no detectable effect on tolerance and intensity ratings. It is concluded that the analgesic properties of intraoral sucrose, seen previously in human newborns and rat pups, may also be present in pre-pubertal children. Further study is needed to determine whether and under what conditions this effect may be replicated. In spite of some limitations, the CPT appears to be a potentially useful tool for pediatric pain research.