Droperidol and dolasetron alone or in combination for prevention of postoperative nausea and vomiting after vitrectomy.

Purpose: Droperidol and the new serotonin-3 antagonists are effective drugs for the prophylaxis of postoperative nausea and vomiting (PONV). The aim of this trial was to evaluate whether dolasetron could be a substitute for droperidol, because the Food and Drug Administration has required a Black Box warning on the droperidol package insert.

Design: Randomized, placebo-controlled, double-blinded trial.

Participants: Inpatients undergoing vitreoretinal surgery (standard 3-port pars plana vitrectomy for proliferative diabetic vitreoretinopathy, complicated retinal detachment, or macular disease, such as macular pucker, macular hole, or choroidal neovascularization).

Intervention: Two hundred forty patients (3x80) receiving droperidol (10 microg. kg(-1)), dolasetron (12.5 mg), or the combination of both drugs administered 5 to 10 minutes before the end of surgery.

Control: Eighty patients received saline placebos as controls.

Methods: Standardized general anesthesia was performed, including benzodiazepine premedication, propofol, atracurium or vecuronium, desflurane in N(2)O/O(2), and a continuous infusion of remifentanil. Postoperative analgesia and antiemetic rescue medication were standardized. Episodes of vomiting, retching, nausea, and the need for additional antiemetics were recorded for 24 hours.

Main Outcome Measures: Severity of PONV (rated by a standardized scoring algorithm) was analyzed as the main end point of the study using the Kruskal-Wallis test.

Results: Data of 304 patients could be analyzed. Mean severity scores in the placebo, dolasetron, droperidol, and combination groups were 1.21, 0.76, 0.47, and 0.30. Incidences of PONV of any severity were 56%, 40%, 28%, and 18%, respectively. The reduction of the incidence of PONV and its severity was statistically significant in the droperidol group and in the combination group relative to the placebo. Dolasetron alone failed to reduce the incidence of PONV. The combination of dolasetron and droperidol showed an additive antiemetic efficacy.

Conclusion: Low-dose droperidol (10 microg. kg(-1)) but not dolasetron (12.5 mg) reduced postoperative nausea and vomiting after vitreoretinal surgery. Dolasetron (12.5 mg) is not an equivalent substitute for droperidol.