Topical amethocaine gel for pain relief of heel prick blood sampling: a randomised double blind controlled trial

Background-Heel prick blood sampling is a commonly performed and painful pr ocedure in the newborn infant. Use of a topical local anaesthetic does not relieve this pain. A 4% w/w amethocaine gel (Ametop) reduces the pain of ve nepuncture in the newborn but has not been tried with heel pricks. Aim-To investigate the effect of topical amethocaine gel on the pain of hee l prick in the newborn infant. Design-Randomised, double blind, placebo controlled trial. Subjects-Sixty newborn infants, gestation 28-42 weeks (median 36), postnata l age 1-16 days (median 5) undergoing routine heel prick blood sampling. Methods-A 1.5 g portion of 4% w/w amethocaine gel or placebo was applied to the skin under occlusion for one hour, then wiped away. Heel prick blood s ampling with a spring loaded lance was performed five minutes later. The pr ocedure was videotaped and pain assessed at one second intervals using an a daptation of the neonatal facial coding system (NFCS). No or minimal pain w as defined as a cumulative score of less than 5 (out of 15) in the three se conds after firing of the lance and as lack of a cry in the first five seco nds. Results-In terms of a low NFCS core and lack of cry (p = 0.12) 20 of 30 (67 %) in the amethocaine group and 13 of 29 (45%) in the placebo group had no or minimal pain in response to the heel prick. The median cumulative NFCS s core over the three seconds after firing the lance was 3 (interquartile ran ge 0-6) in the amethocaine group compared with 5 (interquartile range 1-10) in the placebo group (p = 0.07). These differences are not significant. Conclusions-Topical amethocaine gel does not have a clinically important ef fect on the pain of heel prick blood sampling and its use for this purpose cannot therefore be recommended. Alternative approaches to the relief of pa in from this procedure should be explored.