Terkawi 2015.

Study characteristics
Methods	RCT
Participants	91 women Inclusion criteria: elective CS Exclusion criteria: diabetes, chronic hypertension, gestational hypertension, pre‐eclampsia, cardiac disease, patients with long QT syndrome and known contraindications to spinal anaesthesia Setting: USA
Interventions	Ondansetron versus control Group 1: received 8 mg ondansetron diluted in 10 mL in 0.9% NaCl Group 2: received 10 mL of 0.9% NaCl Study drug was administered over a period of 5 min whilst in sitting position, prior to SAB. All women received standardised aspiration prophylaxis, standardised colloid preload, standardised crystalloid maintenance fluid, standardised monitoring, standardised spinal anaesthetic technique and dose, standardised positioning. Hypotension was managed with boluses of 100 μg of phenylephrine administered incrementally until SBP > 90 mmHg. Bradycardia was managed with 0.4 mg atropine or 0.2 mg glycopyrrolate.
Outcomes	Maternal: incidence of hypotension, incidence of bradycardia, amount of vasopressor and anticholinergic agents given, pruritus, nausea and vomiting, extent of sensory block, estimated blood loss, total fluid administered Neonatal: Apgar scores
Notes	Hypotension was defined as SBP < 90 mmHg or 20% drop in SBP from baseline. Bradycardia was defined as heart rate < 60 bpm.
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 clear
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Drugs prepared by pharmacist
Blinding of outcome assessment (detection bias) All outcomes	Low risk	All research personnel were blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Group 1: 4 excluded (3 due to protocol violation, 1 due to failed SAB) Group 2: 1 excluded (due to protocol violation)
Selective reporting (reporting bias)	Low risk	Not apparent
Other bias	Low risk	None evident