Dr. Christian Apfel's group from Wuerzburg, Germany presented four papers, three of which generated considerable discussion. The first paper entitled " Simplified Risk Score for Predicting Postanesthetic Nausea and Vomiting" concluded that a reliable risk score could be generated from four major predictors: female gender, history of motion sickness or previous PONV, nonsmoking, and the use of postoperative opioids. When 0, 1, 2, 3, or 4 of these risk factors were present, the incidences of PONV were 10% 21%, 39%, 61% and 79%, respectively. The investigators found that the risk scores derived from one hospital center were valid in another center and could be simplified without significant loss of discriminating power.

Dr. Apfel's second poster dealt with the effect of age on vomiting in women who received inhalational anesthesia. The findings suggested that the relative risk of POV increases from the first decade onwards and remained on a high level in the sixth, seventh, and eighth decades (RR 2.9-4.1; all p <0.01). The investigators therefore, concluded that the impact of female gender as a risk factor for POV increases with age, remains significant in the menopause and is, therefore, unrelated to menstruation. These findings are in contradistinction to some other studies that have suggested an emetogenic role for female hormones in triggering PONV during certain phases of the menstrual cycle. The findings also contrast with a recent paper by Sinclair et al (Anesthesiology. 1999; 91:109-118) that reported a 13% reduction in the incidence of PONV for each decade past 50 years.

The third poster from Dr. Apfel's group explored the use of several prophylactic antiemetics in combination with propofol anesthesia for patients at high risk for PONV. All 125 adult patients underwent either ENT or eye surgery. The patients received, prophylactically, either 2.5 mg tropisetron, 62 mg dimenhydrinate, 2.5 mg droperidol, 50 mg metaclopramide, or placebo. Incidences of PN, PV, PONV, and rescue treatment with placebo were 31%, 24%, 35%, and 14%, respectively. The best antiemetic results were obtained with dimenhydrinate where the incidences, respectively, were 11%, 0%, 11%, and 0% The investigators concluded that even with the antiemetic anesthetic agent propofol, additional antiemetic prophylaxis in adults should be considered for those at high risk for PONV.

Dr. Phillip Scuderi from Wake Forest University School of Medicine discussed his very interesting poster, titled "Multimodal Management Eliminates PONV Following Outpatient Laparoscopy." His group hypothesized that a multimodal approach to management of PONV might actually eliminate PONV even in high-risk patients. They randomized female patients undergoing outpatient laparoscopy into one of three groups. Group I (n=60) was managed using a predefined multimodal clinical care algorithm consisting of total intravenous anesthesia (propofol and remifentanil), no N₂₀, no neuromuscular blockade, aggressive IV hydration (25 mL/kg), triple prophylactic antiemetics (ondansetron 1 mg, droperidol 0.625 mg, and dexamethasone 10 mg), and ketorolac 30 mg. Patients undergoing the same surgical procedure who received a standard balanced outpatient anesthetic with ondansetron 4 mg prophylaxis constituted Group II (n=42), and Group III (n=37) received no PONV prophylaxis. None of the Group I patients vomited before discharge compared with 7% in Group II (p=0.07) and 22% in Group III (p=0.003). One patient in Group I required treatment for PONV in the postanesthesia care unit compared with 24% in Group II (p<0.0001) and 41% in Group III (p<0.0001). Time to discharge was also significantly the shortest in Group I. The investigators concluded that multimodal prophylactic management demonstrates superior efficacy in preventing symptomatic PONV compared with routine monotherapy prophylaxis.

The consensus of interactive discussions can be best summarized as follows: 1) No completely effective single antiemetic exists for the prevention of PONV; 2) high risk patients should be identified and targeted for prophylactic antiemetic therapy; 3) combination therapy with agents affecting different receptor sites is superior to monotherapy; 4) drug acquisition costs are only the tip of the iceberg when assessing cost-effectiveness; and 5) an optimal management algorithm may require several iterations.