Swiatkowski 1999.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 2 groups, monoprophylaxis
Participants	Baseline characteristics Ondansetron Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 67 Received treatment (n): NA Analysed (n): 67 Age (mean ± SD, median (IQR), median (range)): 42.9 ± 14.2 Weight (mean ± SD, median (IQR), median (range)): 65.2 ± 9.4 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (isoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): 81.4 Use of perioperative opioids (if yes, which?): intraoperative fentanyl, postoperative pethidine Type of surgery: laparoscopic surgery Droperidol Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): 67 Received treatment (n): NA Analysed (n): 67 Age (mean ± SD, median (IQR), median (range)): 46.5 ± 15.1 Weight (mean ± SD, median (IQR), median (range)): 65.6 ± 10.5 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): NA/NA/0/0 Gender (female in %): 100 Non‐smoker (%): NA History of PONV/motion sickness (%): NA Type of general anaesthesia: inhalational anaesthesia (isoflurane, N₂O) Duration of anaesthesia or surgery (in min; as mean or median): 75.8 Use of perioperative opioids (if yes, which?): intraoperative fentanyl, postoperative pethidine Type of surgery: laparoscopic surgery Included criteria: ASA I and II, scheduled for laparoscopic surgery (laparoscopic cholecystectomy or minor gynaecological laparoscopic surgery) Excluded criteria: preoperative nausea or vomiting requiring therapy; current use of antiemetics, benzodiazepines, or phenothiazine derivatives; previous dyskinetic reactions to droperidol; previous allergy to any of the drugs involved in the study; history of epilepsy; gastrointestinal reflux; liver or renal impairment; use of prostaglandins or ergometrine before or during the procedure Pretreatment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia): no; (history of PONV/motion sickness, non‐smoker, perioperative opioids): unclear
Interventions	Intervention characteristics Ondansetron Dose: 4 mg Time point of administration: immediately after induction of anaesthesia and before surgery Route of administration: IV Rescue antiemetics (if yes, which?): 4.48% (droperidol 1.25 mg IV) Droperidol Dose: 75 µg/kg Time point of administration: immediately after induction of anaesthesia and before surgery Route of administration: IV Rescue antiemetics (if yes, which?): 2.99% (droperidol 1.25 mg IV)
Outcomes	Vomiting (6 to 12 hours) Outcome type: dichotomous outcome Extrapyramidal symptoms (acute dyskinesia, 0 to 24 hours) Outcome type: dichotomous outcome Sedation/drowsiness (0 to 24 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: Glaxo Wellcome Polska supplied ondansetron Country: Poland Setting: inpatient, single‐centre Author's name: J. Świa̧tkowski Institution: University Department of Anaesthesiology and Intensive Therapy, Medical University School, Lublin, Poland Email: NA Address: University Department of Anaesthesiology and Intensive Therapy, Medical University School, Jaczewskiego 8, 20‐090 Lublin, Poland Duration of study: NA Language: English Study's primary outcome: incidence of PONV Trial registry number: NA
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "they were randomized to receive either ondansetron (Glaxo Wellcome Polska..." Judgement comment: no information on sequence generation provided
Allocation concealment (selection bias)	Unclear risk	Judgement comment: no statement
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "neither the patient nor the observer during the post‐operative period knew which drug had been administered" Quote: "...both given intravenously (i.v.) by the attending anaesthetist immediately after induction of anaesthesia and before the surgery" Judgement comment: insufficient information on blinding of anaesthetists
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "neither the patient nor the observer during the post‐operative period knew which drug had been administered"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement comment: no missing outcome data
Selective reporting (reporting bias)	Unclear risk	Judgement comment: no reference to a study protocol or trial registry number reported
Other bias	Unclear risk	Quote: "the patients in the two groups treated with droperidol or ondansetron were comparable with regard to the demographic data shown in Table 1. There was no significant difference between two groups" Judgement comment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia): no; (history of PONV/motion sickness, non‐smoker, perioperative opioids): unclear