Effects of atropine and scopolamine on bradycardia and emetic symptoms in otoplasty

Objective: To assess the effects of unilateral or bilateral otoplasty on br adycardia and postoperative nausea and vomiting (PONV) and the efficiency o f transdermal scopolamine in the prophylaxis of PONV. Study Design: Post ho c assessment of the data from a double-blind, randomized study. Methods: Fi fty otoplasty patients were studied; half of them received randomly and in double-blind fashion a transdermal therapeutic system (patch) of scopolamin e (TTS-scopolamine) as prophylaxis against PONV before general anesthesia. The placebo group received atropine 10 mu g.kg(-1) intravenously during ind uction. Results: The scopolamine-treated patients suffered more from modera te peroperative bradycardia (8/25; P < .05) than the atropine-treated patie nts (1/25), Two patients wearing a half of the TTS-scopolamine patch needed intravenous atropine. After unilateral otoplasty, none of the TTS-scopolam ine-treated patients and 50% of the atropine-treated patients suffered from PONV. After bilateral operation, the respective incidences were 39% and 81 % (P < .01). After unilateral otoplasty no patient needed droperidol, but a fter bilateral otoplasty, 12 of 19 of the atropine-treated and 4 of 18 (P < .05) of the scopolamine-treated patients needed droperidol. The mean numbe rs of doses of droperidol mere 0.8 +/- 0.9 and 0.3 +/- 0.6 (P < .05), respe ctively. Two additional patients, wearing half of the TTS-scopolamine patch , suffered from mild central anticholinergic syndrome. Conclusion: TTS-scop olamine offers effective prophylaxis against PONV (auriculoemetic reflex), but does not protect from bradycardia (auriculocardiac reflex) in otoplasty . Cutting of the TTS-scopolamine patch may lead to undesirable side effects .