Nausea is a common problem in ED patients. Antiemetic drugs have been used in the ED for decades, but a recent Cochrane review found no convincing evidence for the benefit of antiemetic drugs over placebo. This was largely based on three placebo-controlled trials, which found mean Visual Analog Scale (VAS) changes for various drugs and placebo, to be similar. However, reliance on mean VAS change as the primary outcome measure has probably been a mistake. It does not give information on the number of improved patients, so these cannot be compared between groups. Alternative primary outcome measures warrant further exploration. Use of a VAS cut-off level indicative of clinically significant symptom improvement would allow comparison of numbers of patients with improved nausea ratings. This is proposed as the best option currently available. Preliminary testing of this outcome measure suggests that the conclusions of past studies may be misleading, and that the question of antiemetic efficacy for ED patients is not yet answered.
- Clinical effectiveness
- Visual Analog Scale