Mauermann E, et al. - In this prospective, observational cohort study, researchers looked for a link between intra-operative fentanyl dose and postoperative nausea and/or vomiting (PONV), in association with a contemporary anaesthesia regimen. They also investigated the link between intra-operative fentanyl dosing and postoperative pain scores. Participants were patients undergoing abdominal, gynaecological or otorhinolaryngological inpatient surgery, who were opioid-naive, without chronic pain, and had a simplified Apfel score at least 2. PONV occurred in 163 (45%) of 363 patients, even when more than 80% of the cohort received total intravenous anaesthesia with propofol and additional antiemetic agents were used in some 66% of patients. Higher 24 h pain scores and a trend towards higher 24 h morphine demands were observed in relation to a higher intra-operative fentanyl dose. Findings revealed higher than expected PONV within the first 24 h, despite the use of propofol and antiemetic agents. An association of intra-operative fentanyl, a modifiable risk factor, with the incidence of PONV and postoperative pain was evident.