Early post-operative nausea and vomiting: A retrospective observational study of 2030 patients

Background The overall risk of post-operative nausea and vomiting (PONV) after general anaesthesia is reportedly 20%-40%. The first episode of PONV may occur early in the post-anaesthesia care unit (PACU) or later at the ward or after discharge at home in an ambulatory setting. This study aimed to investigate and describe the risk of early PONV in a PACU, and we hypothesised that patients and perioperative factors were associated with early PONV. Methods This single-centre retrospective observational study was conducted in a Swedish county hospital from January to June 2017 and included adult patients who underwent surgical procedures under general anaesthesia. Perioperative data were obtained by reviewing the local registry for surgical procedures, medical records and anaesthesia and post-operative charts. Early PONV was defined as PONV occurring up to 4 hours post-operatively at the PACU. Any notification in the medical records, perioperative charts or the registry regarding nausea, vomiting or PONV treatment was regarded as PONV. Univariate and multivariate analyses were performed for factors associated with early PONV. Results A total of 2030 patients were included in the study, of which 9.6% (n = 194) experienced early PONV. Factors associated with a high risk of early PONV were suboptimal PONV prophylaxis, need for opioids, female sex, body mass index >35 kg m(-2) and major surgery and anaesthesia time >= 60 minutes. Conclusion We found that every 10th patient under general anaesthesia experienced early PONV. Suboptimal PONV prophylaxis and previously acknowledged risk factors for PONV were associated with early PONV.