Tsen 2000.

Study characteristics
Methods	RCT
Participants	40 women Inclusion criteria: ASA I and II women not in labour undergoing elective caesarean for term uncomplicated singleton pregnancies, taking only prenatal vitamins and weighing less than 100 kg Exclusion criteria: women with cardiac, pulmonary or renal diseases, or systemic diseases that could influence haemodynamic responses, including pre‐eclampsia, hypertension and diabetes; if women were taking or had a history of taking any medications that could influence haemodynamic responses, including magnesium sulphate, terbutaline or beta‐blockers
Interventions	Ephedrine versus control Group 1: ephedrine 2 mL IV (10 mg) given simultaneously with spinal anaesthetic Group 2: saline 2 mL IV given simultaneously with spinal anaesthetic All women received a standardised crystalloid preload and a standardised spinal anaesthetic technique and dose, followed by standardised surgical positioning. Hypotension was treated with 10 mg IV doses of ephedrine.
Outcomes	Maternal: hypotension; MAP; heart rate; tachycardia (ephedrine group only); hypertension (ephedrine group only); systemic vascular resistance index; stroke index; cardiac index Neonatal: Apgar score < 8 at 5 min
Notes	Hypotension was defined as 20% decrease in MAP
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not described
Allocation concealment (selection bias)	Unclear risk	Sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Blinding: double‐blind – Apgar scored by a paediatrician blinded to the study – no further details
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	As above
Incomplete outcome data (attrition bias) All outcomes	Low risk	No losses to follow‐up
Selective reporting (reporting bias)	Low risk	Not apparent
Other bias	Low risk	Not apparent