Koivuranta 1999.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 2 groups, combination prophylaxis
Participants	Baseline characteristics Droperidol + ondansetron Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): 45 Analysed (n): 45 Age (mean ± SD, median (IQR), median (range)): 42 (21 to 62) Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 23.5 (18.2 to 34.5) ASA I/II/III/IV (n): 33/11/1/0 Gender (female in %): 100 Non‐smoker (%): 67 History of PONV/motion sickness (%): 100/51 Type of general anaesthesia: inhalational anaesthesia (sevoflurane) Duration of anaesthesia or surgery (in min; as mean or median): 95 Use of perioperative opioids (if yes, which?): 300 µg fentanyl intraoperative, 24.6 mg oxycodone postoperative Type of surgery: gynaecological laparoscopic surgery Droperidol + tropisetron Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): 43 Analysed (n): 43 Age (mean ± SD, median (IQR), median (range)): 38 (25 to 51) Weight (mean ± SD, median (IQR), median (range)): NA BMI (mean ± SD, median (IQR), median (range)): 24.0 (17.1 to 37.5) ASA I/II/III/IV (n): 33/10/0/0 Gender (female in %): 100 Non‐smoker (%): 79 History of PONV/motion sickness (%): 100/35 Type of general anaesthesia: inhalational anaesthesia (sevoflurane) Duration of anaesthesia or surgery (in min; as mean or median): 70 Use of perioperative opioids (if yes, which?): 250 µg fentanyl intraoperative, 25.6 mg oxycodone postoperative Type of surgery: gynaecological laparoscopic surgery Included criteria: female, history of previous PONV, scheduled to have elective gynaecological laparoscopic surgery, over 18 years of age, ASA I to III Excluded criteria: pregnant, breastfeeding, evidence of hepatic or other metabolic dysfunction, Parkinson's disease, currently received opioids or medication with antiemetic activity Pretreatment: baseline characteristics (age, BMI, ASA): no. Potential effect modifiers (gender, perioperative opioids, non‐smoker, history of PONV/motion sickness): no; (duration of anaesthesia): yes
Interventions	Intervention characteristics Droperidol + ondansetron Dose: droperidol 0.75 mg, ondansetron 8 mg Time point of administration: droperidol after induction of anaesthesia, ondansetron at the end of the procedure Route of administration: IV Rescue antiemetics (if yes, which?): 31% (droperidol 0.75 mg) Droperidol + tropisetron Dose: droperidol 0.75 mg, tropisetron 5 mg Time point of administration: droperidol after induction of anaesthesia, tropisetron at the end of the procedure Route of administration: IV Rescue antiemetics (if yes, which?): 40% (droperidol 0.75 mg)
Outcomes	Vomiting (0 to 24 hours) Outcome type: dichotomous outcome Vomiting (0 to 2 hours) Outcome type: dichotomous outcome Nausea (0 to 24 hours) Outcome type: dichotomous outcome Subjects with any SAE (0 to 24 hours) Outcome type: dichotomous outcome Extrapyramidal symptoms (0 to 24 hours) Outcome type: dichotomous outcome Headache (0 to 24 hours) Outcome type: dichotomous outcome Sedation/drowsiness (0 to 2 hours) Outcome type: dichotomous outcome Adverse events (general notes in the publication, 24 hours' observation) Outcome type: general notes on side effects
Identification	Sponsorship source: NA Country: Finland Setting: inpatients, multi‐centre (2) Author's name: M. Koivuranta Institution: Department of Anaesthesiology, Oulu University Hospital, Ouluandt Department of Anaesthesiology, Lappland Central Hospital, Rovaniemi, Finland Email: NA Address: Department of Anaesthesiology, Oulu University Hospital, Kajaanintie 50,FIN‐90220 Oulu, Finland Language: English Duration of study: NA Trial registry number: NA Study's primary outcome: NA
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Judgement comment: quote: "randomized". No further information on sequence generation provided
Allocation concealment (selection bias)	Low risk	Judgement comment: quote: "the treatment allocation codes were contained in sealed opaque envelopes and for each consecutive patient recruited the assisting nurses opened the next envelope in order and administered the study drug but did not participate in the post‐operative assessment"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Judgement comment: quote: "in a random double‐blind fashion to receive intravenously (i.v.) (...) either a slow injection of ondansetron 8 mg or tropisetron 5 mg, diluted to the same volume of saline"; "the assisting nurses opened the next envelope in order and administered the study drug but did not participate in the post‐operative assessment"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Judgement comment: quote: "all observations were made without the interviewer being aware of the study treatment"; "all observations were made without the interviewer being aware of the study treatment"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: quote: "two patients were excluded from the final analysis because of a protocol violation"
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no reference to a study protocol or trial registry number reported
Other bias	High risk	Judgement comment: quote: "furthermore, this was in spite of the fact that the patients in the ondansetron group had a higher incidence of motion sickness, received a longer anaesthetic and larger dose of fentanyl" Baseline characteristics (age, BMI, ASA): no. Potential effect modifiers (gender, perioperative opioids, non‐smoker, history of PONV/motion sickness): no; (duration of anaesthesia): yes