Loo 2002.

Study characteristics
Methods	RCT
Participants	40 women Inclusion criteria: undergoing elective CS, ASA I, age 18 to 40 years, height > 150 cm, weight < 100 kg, full‐term singleton fetus with no congenital abnormalities, no polyhydramnios, no intrauterine growth retardation, and estimated fetal weight > 2500 g
Interventions	Ephedrine + crystalloid co‐load versus crystalloid preload Group 1: prophylactic ephedrine 6 mg IV and 1000 mL Ringer's lactate commenced immediately after spinal anaesthesia Group 2: preload of 1000 mL Ringer's lactate All women received a standardised spinal anaesthetic technique and dose.
Outcomes	Maternal: hypotension (defined as SBP < 100 mmHg); BP; heart rate; time to block; ephedrine dose Neonatal: Apgar scores
Notes	Hypotension defined as SBP < 100 mmHg
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	Allocation concealment: "divided into two groups"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Blinding: described as "double‐blinded" but no further details provided
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	As above
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Losses to follow‐up: not stated
Selective reporting (reporting bias)	Unclear risk	Unclear reporting
Other bias	Low risk	None apparent