AGE-RELATED RESPONSE TO LIDOCAINE-PRILOCAINE (EMLA) EMULSION AND EFFECT OF MUSIC DISTRACTION ON THE PAIN OF INTRAVENOUS CANNULATION

Objective. To compare the efficacy of a local anesthetic cream and mus ic distraction in reducing or preventing pain from needle puncture (in travenous cannulation) in children. A secondary aim was to examine the influence of age on the pain report and behavior and on the therapeut ic outcome. Methodology. Children aged 4 to 16 years (N = 180) who wer e to undergo surgery under general anesthesia via intravenous cannulat ion were randomly allocated to one of three interventions. The compari son of lidocaine-prilocaine emulsion (EMLA, Astra) and a placebo emuls ion was double-blind. Stratification by age group (4 to 6, 7 to 11, 12 to 16) ensured an equal number of children (20) in each intervention/ age group category. A global assessment of the behavioral reaction to the procedure was made by the principal investigator, taking into acco unt vocal, verbal, facial, and motor responses. The child was asked to assess pain severity on the Faces Pain Scale (FPS) and a visual analo gue toy (VAT). The scales were applied conservatively as ordinal scale s: FPS 0 to 6; VAT 0 to 10. Results. Children who received lidocaine-p rilocaine emulsion reported less pain (mean FPS score = 1.42) compared with placebo emulsion (mean FPS score = 2.58) and with music distract ion (mean FPS = 2.62). There was a highly significant therapeutic effe ct (P < .001) on the self-report and behavioral scores. Younger childr en, regardless of intervention, reported significantly more pain than the older children (mean FPS scores: 2.85, 2.33, 1.43 for age groups 4 to 6, 7 to 11, and 12 to 16 respectively; P < .001). The superiority of the local anesthetic emulsion was maximal in the youngest age group (4 to 6) almost eliminating pain-related behavior, and multiple regre ssion analysis confirmed significant age and treatment effects and rev ealed interaction between therapeutic effect and age. Although a trend favoring the active emulsion was evident in the older children (7 to 11,12 to 16) the differences were not significant. The pain scores wer e influenced by the type (gauge) of cannula, but this did not affect t he conclusion regarding therapeutic and age effects. There was no infl uence of sex, experience with venipuncture, or whether the child was a nxious on arrival in the operating room. Conclusions. The results show that lidocaine-prilocaine emulsion is highly effective in preventing pain from venipunctures in young children, the group in most need of p revention.