The effect of transdermal scopolamine plus intravenous dexamethasone for the prevention of postoperative nausea and vomiting in patients with epidural PCA after major orthopedic surgery

BACKGROUND: Postoperative nausea and vomiting (PONV) is common complication of Patient-Controlled Analgesia (PCA) after surgery. The authors sought to determine whether a transdermal scopolamine (TDS) patch in combination with IV dexamethasone is more effective than IV dexamethasone alone or IV dexamethasone plus IV ramosetron for reducing PONV in patients receiving epidural PCA after major orthopedic surgery. METHODS: 120 patients that received epidural PCA with hydromorphone and ropivacaine after major orthopedic surgery under spinal anesthesia were allocated to 3 groups: Group D (n = 40) received IV dexamethasone 8 mg, Group DR (n = 40) received IV dexamethasone 8 mg plus IV ramosetron 0.3 mg, Group DS (n = 40) received IV dexamethasone 8 mg plus a TDS patch (Group DS, n = 40). Nausea and vomiting incidences, VAS for nausea, the use of additional antiemetics, and adverse effects (a dry mouth, blurred vision, drowsiness) during the first 24 hours postoperatively were subjected to analysis. RESULTS: The DS Group had a significantly higher rate of complete remission of PONV than the D and DR groups (82.5% vs 47.5%, and 50.0%, respectively), and had lower rates of nausea (17.5% vs 55.0%, and 50.0%), and vomiting (10.0% vs 50.0%, and 25.0%), and required less antiemetics (5.0% vs 35.0%, 22.5%) than group D and Group DR during the first 24 hours after surgery. Furthermore, no inter-group differences were observed with respect to adverse effects in the three groups. CONCLUSIONS: The prophylactic use of a TDS patch plus dexamethasone was found to be a more effective means of preventing PONV in patients that received epidural PCA after major orthopedic surgery than dexamethasone alone or dexamethasone plus ramosetron without adversely affecting side effects.