Sahoo 2012.

Study characteristics
Methods	RCT
Participants	52 women ASA 1‐2 undergoing elective CS with spinal anaesthesia, with no contraindications to spinal anaesthesia.
Interventions	Intervention: 5HT3 antagonist (Comparison 1) Ondansetron 4 mg in 10 mL saline prior to anaesthesia. N = 26. Compaison: placebo 10 mL saline prior to spinal anaesthesia. N = 26.
Outcomes	Heart rate, BP, oxygen saturations, nausea, vomiting, pain.
Notes	Setting: Kolkata, India. Dates: September to December 2008 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 randomisation.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "double blind". No additional information about participant blinding
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Observations were made by an anaesthetist blinded to group allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	None apparent.
Selective reporting (reporting bias)	Unclear risk	We did not assess the study protocol.
Other bias	Low risk	Nil apparent.