Sanansilp 1998.

Study characteristics
Methods	RCT
Participants	97 women undergoing CS under epidural, ASA 1‐2, without history of convulsions, Parkinsonism, drug abuse and psychiatric problems.
Interventions	Group 1: dopamine antagonist (Comparison 2) Epidural droperidol 2.5 mg (+ epidural morphine 5 mg). N = 32. Group 2: dopamine antagonist (Comparison 2) IV droperidol 2.5 mg (+ epidural morphine 5 mg). N = 32. Group 3. placebo Epidural morphine alone. N = 33.
Outcomes	Pruritis, nausea, vomiting, sedation, pain.
Notes	Setting: Siriraj Hospital, Bangkok, Thailand. Dates: not reported. Funding source: not reported. Declaration of interest: not reported. This study currently provides no data for the review because the data are presented graphically. We have wrote to the authors in 2009 requesting the specific data.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information provided.
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote; "double blind".
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not specifically described.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Appears to be no exclusions or loss to follow‐up.
Selective reporting (reporting bias)	Unclear risk	We did not assess the trial protocol.
Other bias	Low risk	No evidence of other biases.