Postoperative nausea and vomiting in patients undergoing total abdominal hysterectomy under spinal anaesthesia: a randomized study of ondansetron prophylaxis.

BACKGROUND AND OBJECTIVE: Patients undergoing total abdominal hysterectomy under general anaesthesia have a high risk of developing postoperative nausea and vomiting (PONV). The aim of this study was to evaluate the incidence of PONV in patients undergoing total abdominal hysterectomy under spinal anaesthesia with intravenous patient-controlled analgesia (PCA) using morphine and to compare its incidence with and without antiemetic prophylaxis.

METHODS: Thirty-four patients undergoing total abdominal hysterectomy under spinal anaesthesia with i.v. PCA morphine postoperatively were divided into two groups. The first (n = 17) received ondansetron prophylaxis near the end of surgery while the second (n = 17) received no prophylaxis. Morphine consumption, emetic episodes (on a 3-point scale), patient satisfaction (visual analogue score), sedation and pruritus were evaluated 2, 4, 6, 9, 12, 18 and 24h postoperatively.

RESULTS: Patient characteristics, postoperative morphine consumption (43.3 +/- 7.6 vs. 40.3 +/- 12.3 mg) and peristaltic recovery time (16.9 +/- 5 vs. 18.4 +/- 5.2 h) were similar in both groups. Overall nausea and vomiting were significantly lower in the ondansetron prophylaxis group than in the group without prophylaxis (52.9% vs. 88.2%, P < 0.05). Though nausea alone was higher in the prophylaxis group (41.2% vs. 29.4%), nausea with vomiting was significantly lower in the prophylaxis group (11.8% vs. 58.8%, P < 0.01). Patients' satisfaction scores were higher in the ondansetron group at all times and the difference was significant (P < 0.05) 4 h postoperatively.

CONCLUSIONS: The incidence of PONV in patients undergoing total abdominal hysterectomy under spinal anaesthesia with i.v. PCA morphine is very high (88.2%). Antiemetic prophylaxis with ondansetron is highly recommended in this patients group resulting in a lower incidence of nausea and vomiting, and significantly improves patient' satisfaction and life quality in the early postoperative period.