Randomized placebo-controlled trial of droperidol and ondansetron for adult emergency department patients with nausea: Demonstration of a new outcome measure.

Background: ED-based trials have repeatedly failed to demonstrate superiority for antiemetic drugs over placebo,1 but the clinical significance of reported between-group differences in mean visual analogue scale (VAS) change is obscure.2 Recent research suggests that a VAS change cut-off level can reliably identify improved patients.3 This would allow more clinically meaningful between-group comparisons to be made. Objective(s): To compare intravenous (IV) droperidol 1.25 mg and ondansetron 8 mg IV with 0.9% saline placebo for adult ED patients with nausea. A VAS change cut-off level was used as the primary outcome measure. Method(s): A randomised controlled trial was conducted at Monash Health, designed to demonstrate superiority of the active drugs over placebo. The primary outcome measure of symptom improvement was defined as a VAS change of >= -8 mm from baseline at 30-minute posttreatment. Mean VAS changes per group, and percentages experiencing the desired treatment effect were also compared. Result(s): Of 215 patients, 73 (34%), 71 (33%) and 71 (33%) received droperidol, ondansetron and placebo. Symptom improvement occurred in 75%, 80% and 76% respectively; between-group differences are shown in Table 1. Mean VAS changes were -29 mm (95% CI: -36 to -23), -34 mm (95% CI: -41 to -28), and -24 mm (95% CI: -29 to -19), respectively. Desired treatment effect was experienced by 77%, 73% and 59% respectively; between-group differences are shown in Table 2. Conclusion(s): Superiority was not demonstrated for droperidol or ondansetron over placebo. The new primary outcome measure provided results which were clinically meaningful and easily understandable. (Table Presented).