[Effect of the menstrual cycle and ondansetron on postoperative nausea and vomiting]

The incidence of postoperative nausea and vomiting (PONV) has been studied in a prospective group of 92 female patients in the generative period, undergoing thyroid surgery. In a subgroup of 47 examinees we analyzed PONV incidence according to the surgery time within the frame of their menstrual cycle. The highest number was observed in periovulatory and premenstrual periods (p < 0.02). In the formal trial, 24 patients that randomly received ondansetron (8 mg in 4 mL i.v.) and significantly less PONV than their 21 placebo controls (4 mL saline i.v.): 4 or 16.8% vs. 11 or 53.6% (p < 0.04).