Comparison of the Effects of Vapocoolant Spray and Topical Anesthetic Cream on Pain during Intraarticular Injection of the Shoulder: a Randomized Double-Blind Controlled Trial.

OBJECTIVE: This study was performed to compare the effects of a vapocoolant spray and an eutectic mixture of local anesthetics (EMLA) cream on reducing pain during intraarticular (IA) injection of the shoulder.

DESIGN: Double-blind randomized placebo-controlled clinical trial.

SETTING: University hospital.

PARTICIPANTS: Sixty-three patients who underwent IA injection of the shoulder joint were randomized into the spray group, EMLA group, or placebo group.

INTERVENTION: Placebo cream + vapocoolant spray (spray group), EMLA cream + placebo spray (EMLA group), or placebo cream + placebo spray (placebo group) before IA injection.

MAIN OUTCOME MEASURES: A 100-mm visual analog scale (VAS) for injection pain and 5-point Likert scales for participant satisfaction and preference for repeated use were administered immediately after IA injection.

RESULTS: The VAS scores for pain during IA injection were 30.0 (95% confidence interval: 19.7-41.2) in the spray group, 50.0 (37.7-63.0) in the EMLA group, and 53.8 (41.6-65.0) in the placebo group (F = 6.403, P < 0.01). The spray group showed significantly better Likert scale scores than the placebo group for participant satisfaction (P = 0.003) and preference for repeated use (P < 0.001).

CONCLUSIONS: Vapocoolant spray was effective in reducing pain during IA injection of the shoulder.