Post-operative nausea and vomiting in bariatric surgery patients: an observational study.

BACKGROUND: The risk of post-operative nausea and vomiting (PONV) in patients undergoing bariatric surgery is unclear. The aim of the study was to investigate the risk of PONV and the use and effectiveness of PONV prophylaxis.

METHODS: This prospective observational study included 74 patients undergoing bariatric surgery with total intravenous anaesthesia. Patients were given PONV prophylaxis based on published guidelines and a simplified PONV risk score. Perioperative data were collected and a questionnaire was used at 2, 4, 6, 24, 48 and 72 h after the operation to evaluate PONV. Data are presented as risk (%) with the 95% confidence interval.

RESULTS: Sixty five per cent (54-75) of the patients experienced PONV in the first 24 post-operative hours and the risk increased with the number of risk factors for PONV. PONV occurred in 78% (66-87) of women and 26% (12-49) of men during the first 24 h. In relation to the guidelines, one patient received suboptimal PONV prophylaxis, 23% received optimal prophylaxis and 76% supra-optimal prophylaxis. The risk of PONV was 82% (59-94) with optimal prophylaxis and 59% (46-71) with supra-optimal prophylaxis. Of all patients, 34% (24-45) experienced severe PONV in the first 24 h that limited their activity.

CONCLUSIONS: The incidence of PONV in bariatric surgery patients was high despite a PONV prophylaxis regime following current guidelines. These results cast doubt as to the effectiveness of the usual PONV prophylaxis in this patient group and point to the need for further investigation of PONV prophylaxis and treatment in bariatric surgery patients.