Comparison of the Effects of Vapocoolant Spray and Topical Anesthetic Cream on Pain During Needle Electromyography in the Medial Gastrocnemius

Abstract

Objective: To compare the effects of a vapocoolant spray and an eutectic mixture of local anesthetics (EMLA) cream in reducing pain during needle electromyography examination. Design: Randomized controlled trial. Setting: Physical medicine and rehabilitation department of a university hospital. Participants: Adults who underwent needle electromyography (N=99) were randomized to 1 of 2 experimental groups or the control group. Two patients dropped out during the study. Interventions: In the experimental groups, vapocoolant spray or EMLA cream were applied before needle electromyography. In the control group, needle electromyography was performed without pretreatment. Main Outcome Measures: Intensity of pain associated with needle electromyography was assessed using a 100-mm visual analog scale (VAS). Patient satisfaction and preference for repeated use were measured using a 5-point Likert scale. Results: VAS score for pain intensity was significantly lower in the spray group (31.9; 95% confidence interval [CI], 22.0-41.7) compared with the control group (52.9; 95% CI, 45.9-60.0; P=.002), whereas there was no significant difference between the EMLA cream group (42.4; 95% CI, 34.2-50.7) and the control group. Patient satisfaction and preference for repeated use were higher in the spray group than the EMLA group. Conclusions: Vapocoolant spray was more effective than EMLA cream in reducing pain during needle electromyography. Archives of Physical Medicine and Rehabilitation 2013;94:919-24 (C) 2013 by the American Congress of Rehabilitation Medicine