Warmed Versus Room Temperature Saline Solution for Ocular Irrigation: A Randomized Clinical Trial

Author: Ernst AA, Thomson T, Haynes M, Weiss SJ

Publication: Ann Emerg Med 1998 Dec;32(6):676-9

STUDY OBJECTIVE: To test the hypothesis that ocular irrigation with warm saline solution is more comfortable than irrigation with room temperature saline solution in normal volunteers.

METHODS: The study was a randomized, single-blind crossover trial, in which each subject received 30 mL warmed and 30 mL room temperature saline solution in opposite eyes. The solutions (warmed versus room temperature) and the order of irrigation (right eye versus left) were separately randomized. Physicians were blinded to solution temperature. Subjects rated the discomfort of irrigation on separate visual analog scales (VAS). The study had 80% power to detect at least a 12-mm difference in VAS readings.

RESULTS: Thirty-five volunteers were enrolled in the study. There was no gender effect or order effect for the 2 solutions. The mean VAS score for warmed saline solution was 15 mm+1-15 mm (SD). The mean VAS score for room temperature saline was 34 mm+/-24 mm (SD), (95% confidence interval for difference of 19 mm [10 mm to 28 mm], P <.0001, Witcoxon signed rank test). CONCLUSION: Warmed saline solution was both clinically and statistically more comfortable than room temperature saline solution as an ocular irrigant among normal volunteers. NOTE: “Warmed solution” was defined in the study as being between 90-100 degrees F (32.2 and 37.8 degrees C); “room temperature” is approximately 70 degrees F (21.1 degrees C)