Chewing gum for the treatment of postoperative nausea and vomiting: a pilot randomized controlled trial

Background. A novel treatment, chewing gum, may be non-inferior to ondansetron in inhibiting postoperative nausea and vomiting (PONV) in female patients after laparoscopic or breast surgery. In this pilot study, we tested the feasibility of a large randomized controlled trial. Methods. We randomized 94 female patients undergoing laparoscopic or breast surgery to ondansetron 4 mg i.v. or chewing gum if PONV was experienced in the postanaesthesia care unit (PACU). The primary outcome was full resolution of PONV, with non-inferiority defined as a difference between groups of <15% in a per protocol analysis. Secondary outcomes were PACU stay duration, anti-emetic rescue use, and acceptability of anti-emetic treatment. The feasibility of implementing the protocol in a larger trial was assessed. Results. Postoperative nausea and vomiting in the PACU occurred in 13 (28%) ondansetron patients and 15 (31%) chewing gum patients (P = 0.75). Three chewing gum patients could not chew gum when they developed PONV. On a per protocol basis, full resolution of PONV occurred in five of 13 (39%) ondansetron vs nine of 12 (75%) chewing gum patients [risk difference 37% (6.3-67%), P = 0.07]. There was no difference in secondary outcomes between groups. Recruitment was satisfactory, the protocol was acceptable to anaesthetists and nurses, and data collection was complete. Conclusions. In this pilot trial, chewing gum was not inferior to ondansetron for treatment of PONV after general anaesthesia for laparoscopic or breast surgery in female patients. Our findings demonstrate the feasibility of a larger, multicentred randomized controlled trial to investigate this novel therapy. Clinical trial registration. Australian New Zealand Clinical Trials Registry: ACTRN12615001327572.