Nivatpumin 2016.

Study characteristics
Methods	RCT
Participants	168 women Inclusion criteria: age > 18 years, ASA I‐II, term singleton pregnancy, elective caesarean delivery under spinal anaesthesia Exclusion criteria: diabetes mellitus other than gestational diabetes, hypertension, BMI > 40 kg/m², complicated pregnancy, allergy to study drugs, long QT syndrome, contraindications to spinal anaesthesia Setting: Thailand
Interventions	Ondansetron versus ephedrine versus control Group 1: ephedrine 10 mg IV Group 2: ondansetron 8 mg IV Group 3: normal saline IV Above interventions were diluted in 10 mL 0.9% saline and administered immediately after spinal anaesthesia. All women received the same aspiration prophylaxis, monitoring, crystalloid preload, anaesthetic technique and dose. If hypotension developed, women received ephedrine 5‐10 mg or noradrenalin 4‐8 μg IV (choice of agent was up to the attending anaesthetist). Bradycardia was treated with IV atropine 0.6 mg.
Outcomes	Maternal: hypotension, nausea and vomiting, incidence of vasopressor and dose of vasopressor used Neonatal: Apgar scores
Notes	Hypotension defined as decrease in SBP > 20% of baseline or SBP < 90 mmHg. Bradycardia defined as heart rate < 50 bpm.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation table
Allocation concealment (selection bias)	Low risk	Sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only 2 women were excluded due to protocol violations
Selective reporting (reporting bias)	Low risk	None apparent
Other bias	Low risk	None apparent