Pan 1996.

Study characteristics
Methods	RCT
Participants	48 women undergoing elective CS under epidural anaesthesia, ASA 1‐2, not planning to breast feed, no psychiatric disease or motion sickness.
Interventions	Intervention 1: 5‐HT3antagonist (Comparison 1) Ondansetron, IV ‐ 8 mg. N = 16. Intervention 2: dopamine antagonist (Comparison 2) Droperidol, IV ‐ 0.625 mg. N = 16. Comparison: placebo Normal saline, IV. N = 16.
Outcomes	Intraoperative nausea, vomiting (combined to make a cumulative score).
Notes	Setting: University Medical Centre, Virginia, USA. Dates: not reported. Funding source: not reported. Declaration of interest: not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated.
Allocation concealment (selection bias)	Unclear risk	Who made up the syringes was not described.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Double blind". Assessor unaware of allocation.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Assessor unaware of allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss of participants described.
Selective reporting (reporting bias)	Unclear risk	We did not assess the protocol.
Other bias	Low risk	No baseline differences.