Ali Melkkila 1996.

Study characteristics
Methods	Study design: randomized controlled trial Study grouping: 3 groups, monoprophylaxis
Participants	Baseline characteristics Tropisetron Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): NA Analysed (n): 40 Age (mean ± SD, median (IQR), median (range)): 45.4 ± 15.5 Weight (mean ± SD, median (IQR), median (range)): 73.4 ± 17.6 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): 23/6/11/0 Gender (female in %): 32.5 Non‐smoker (%): NA History of PONV/motion sickness (%): 25/NA Type of general anaesthesia: balanced anaesthesia (N₂O, isoflurane, fentanyl) Duration of anaesthesia or surgery (in min; as mean or median): 1.58 Use of perioperative opioids (if yes, which?): induction fentanyl 2 µg/kg, maintenance 1 µg/kg to clinical parameters Type of surgery: ophthalmic surgery Metoclopramide Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): NA Analysed (n): 40 Age (mean ± SD, median (IQR), median (range)): 46 ± 18.1 Weight (mean ± SD, median (IQR), median (range)): 73.2 ± 12.6 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): 19/11/10/0 Gender (female in %): 42.5 Non‐smoker (%): NA History of PONV/motion sickness (%): 32.5/NA Type of general anaesthesia: balanced anaesthesia (N₂O, isoflurane, fentanyl) Duration of anaesthesia or surgery (in min; as mean or median): 1.78 Use of perioperative opioids (if yes, which?): induction fentanyl 2 µg/kg, maintenance 1 µg/kg to clinical parameters Type of surgery: ophthalmic surgery Placebo Assessed for eligibility (n): ‐ Enrolled (n): ‐ Randomized (n): NA Received treatment (n): NA Analysed (n): 40 Age (mean ± SD, median (IQR), median (range)): 44.7 ± 14.9 Weight (mean ± SD, median (IQR), median (range)): 70.9 ± 14.9 BMI (mean ± SD, median (IQR), median (range)): NA ASA I/II/III/IV (n): 22/9/9/0 Gender (female in %): 50 Non‐smoker (%): NA History of PONV/motion sickness (%): 25/NA Type of general anaesthesia: balanced anaesthesia (N₂O, isoflurane, fentanyl) Duration of anaesthesia or surgery (in min; as mean or median): 1.82 Use of perioperative opioids (if yes, which?): induction fentanyl 2 µg/kg, maintenance 1 µg/kg to clinical parameters Type of surgery: ophthalmic surgery Included criteria: between 18 and 75 years of age, scheduled for elective ophthalmic surgery under general anaesthesia and studied over a period of 12 months Excluded criteria: childbearing potential or lactation, taking concomitant medication that could influence gastrointestinal motility or vomiting, coexisting conditions that could interfere with evaluation of study drugs, or putting the patient at risk (e.g. congestive heart failure, liver disease, renal failure, hypersensitivity to study drugs, history of drug/alcohol abuse) Pretreatment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, history of PONV): no; (history of motion sickness, non‐smoker, perioperative opioids): unclear
Interventions	Intervention characteristics Tropisetron Dose: 0.1 mg/kg Time point of administration: at end of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): (17.5%) droperidol 2.5 mg IV Metoclopramide Dose: 0.25 mg/kg Time point of administration: at end of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): (15%) droperidol 2.5 mg IV Placebo Dose: saline Time point of administration: at end of anaesthesia Route of administration: IV Rescue antiemetics (if yes, which?): (27.5%) droperidol 2.5 mg IV
Outcomes	Vomiting (0 to 24 hours) Outcome type: dichotomous outcome Nausea (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: NA Country: Finland Setting: inpatient, single‐centre Author's name: T. Ali‐Melkkilä Institution: Department of Anaesthesia, Paijat‐Hame Central Hospital, Lahti, Finland Email: NA Address: Department of Anaesthesia, Paijat‐Hame Central Hospital, ST‐15850 Lahti, Finland Duration of study: NA Language: English Study's primary outcome: the primary endpoints were the number of emetic episodes (nausea or vomiting/retching) during the first 24 hours after surgery Trial registry number: NA
Notes	None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "the patients were randomly allocated" 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	Low risk	Quote: "anaesthesia; the investigators and the observers were blinded as to the agent given"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "anaesthesia; the investigators and the observers were blinded as to the agent given"
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 three groups were comparable with regard to age, weight, height, gender distribution and ASA physical status. The number of patients who had been anaesthetised previously was higher in the placebo group, but there was no statistically significant difference between the three groups on the occurrence of PONV after previous general anaesthesia" Judgement comment: baseline characteristics (age, weight, ASA): no. Potential effect modifiers (gender, duration of anaesthesia, history of PONV): no; (history of motion sickness, non‐smoker, perioperative opioids): unclear