The effect of transdermal scopolamine on the incidence and severity of postoperative nausea and vomiting in a group of high-risk patients given prophylactic intravenous ondansetron.

Specific risk factors place patients at greater risk for postoperative nausea and vomiting (PONV). Routinely, these patients are treated prophylactically with intravenous (IV) ondansetron or transdermal (TD) scopolamine. No study has examined what effect using a combination of these prophylactic treatments would have on the incidence of PONV in a group of high-risk patients. A total of 56 patients at high risk for PONV were treated prophylactically with IV ondansetron and randomized to receive a TD scopolamine patch or placebo. Demographics, incidence, and severity of PONV and side effects and antiemetic requirements were measured. Nausea was measured using a 0 to 10 verbal numeric rating scale. Descriptive and inferential statistics were used for analysis. No difference in demographics or the incidence of side effects was noted between groups. Patients in the scopolamine group had a lower incidence of PONV (P = .043), longer time to first reported nausea (P = .044), longer time to first episode of emesis (P = .031), and decreased supplemental antiemetic requirements (P = .016) compared with the placebo group. Based on this study, we recommend using a combination of TD scopolamine and IV ondansetron to prevent PONV in patients identified as high risk for PONV.