Concentrated sucrose solution seems to reduce crying and the autonomic effects of a painful procedure in healthy normal babies. Sucrose may be a useful and safe analgesic for minor procedures in neonates.

In a randomised, double blind, controlied study the ability of 5Ol lignocaine ointment to reduce the behavioural response to heel lance in 30 healthy neonates was assessed. Five per cent lignocaine ointment applied to the heel under an occlusive dressing for one hour before heel prick did not reduce the infants' behavioural response to the heel prick procedure. (Arch Dis Child 1995; 72: F49-F5 1) Keywords: topical lignocaine, heel lance, behavioural response.Local anaesthetics act by blockading the sodium channels in the cell membranes of sensory nerves, and so blocking nerve conduction. EMLA cream is a mixture of two local anaesthetic agents, lignocaine and prilocaine, suspended in an oil in water emulsion. The physical properties of EMLA cream make it an ideal drug for transdermal application. When applied to intact skin under an occlusive dressing the analgesic effect can last for several hours.' EMLA is widely used in infants and children and produces a reduction in pain response to procedures such as venepuncture and lumbar puncture.2Although it has been shown that lignocaine and prilocaine do not reach toxic concentrations following transdermal application of EMLA in children over 3 months of age,3 prilocaine has been implicated in the development of methaemoglobinaemia in infancy.4 A metabolite of prilocaine oxidises haemoglobin to methaemoglobin. The enzyme responsible for the reversal of this oxidation, cytochrome b5 reductase, is present in low concentrations in infancy, and this increases the risk of methaemoglobinaemia.5Because EMLA is not suitable for use in neonates, if local anaesthesia is required the only method of giving this is by subcutaneous infiltration, which means an additional painful procedure. If an alternative local anaesthetic agent without prilocaine was available, which was effective when applied topically, this could be used in neonates and infants under 1 month of age.We have already shown a consistent behavioural response to the painful stimulus of heel lance in healthy neonates,6 and were interested to see if this behavioural response could be reduced by the use of 5% lignocaine ointment before the procedure. MethodsUsing the results of our previous study of behavioural response to heel lance, we felt that if the local anaesthetic were to be judged successful in reducing the behavioural response to pain then the number of behaviour items induced following the heel lance stimulus should be reduced from a median of 5, to a median of 1.5 We calculated that 15 infants would be required in both the treatment and placebo groups to demonstrate this reduction (90% power, 5% significance).Healthy infants who needed capillary blood samples for bilirubin estimation were recruited to the study following consent from the mother. The study was approved by the hospital ethics committee.The study was of a double blind placebo design. Infants were allocated to receive 5% lignocaine ointment or control (emulsifying ointment) in a random manner. About 0 5 g ointment was applied to the ...