A randomized controlled trial of the effectiveness of topical amethocaine in reducing pain during arterial puncture

Objective: To determine if topical 4% amethocaine gel can reduce the pain associated with arterial punctures. Design: Randomized, placebo-controlled, double-blinded trial with parallel groups. Setting: Teaching hospital. Patients: Adults requiring arterial punctures for blood gas estimation as part of routine care. Interventions: Four percent amethocaine gel applied for 30 min prior to the radial arterial puncture, compared with a placebo gel. Main outcome measures: Pain scored on a visual analog scale from 0 to 100, and heart rate during the procedure. Results: The mean pain score for the amethocaine group was 16.0 (SD, 23.3) and for the placebo group was 20.7 (SD, 18.5). The mean heart rates during arterial puncture were 84.1 beats/min (SD, 10.7) for the amethocaine group, and 83.8 beats/min (SD, 12.7) for the placebo group. These differences were not statistically significant. Conclusion: The topical use of 4% amethocaine gel does not reduce the pain associated with arterial puncture.