Relative effectiveness of lignocaine-prilocaine emulsion and nitrous oxideinhalation for routine preoperative laboratory testing

We studied the impact of age-related factors and the benefits of 50% nitrou s oxide or EMLA cream in 108 children undergoing preoperative laboratory te sting. Procedural pain was assessed by behavioural scores (CHEOPS) and pain intensity ratings. Age, preexisting behavioural distress and difficulty of venous access were significant predictors of outcome in univariate analysi s. Nitrous oxide and EMLA cream were both effective in lowering pain relate d behaviour and pain ratings generated by the different adult observers and the children where applicable. EMLA cream was more effective than 50% nitr ous oxide in children 1-4 years old. Although EMLA cream was responsible fo r a 28+/-5 min prolongation of waiting time at the clinic, the present resu lts suggest that it should remain the first line intervention to alleviate pain from venepuncture in paediatric outpatients.