Olsen 1994.

Study characteristics
Methods	RCT
Participants	28 women Inclusion criteria: healthy parturients at term scheduled for elective CS due to disproportion or breech presentation
Interventions	Prophylactic ephedrine + crystalloid preload versus crystalloid preload alone Group 1: 750 mL isotonic saline plus 20 mL/kg preload Group 2: 750 mL isotonic saline plus 500 mL preload followed by ephedrine bolus (0.15 mg/kg) and ephedrine infusion (0.4 mg/kg/h); ephedrine commenced after spinal anaesthetic All women received standardised positioning, and a standardised spinal anaesthetic technique and dose followed by standardised surgical positioning.
Outcomes	Maternal: hypotension; BP; level of block; induction to incision/incision to birth times; ephedrine dose Neonatal: umbilical pH; Apgar scores
Notes	Hypotension was defined as > 10 mmHg decrease in MAP (reported only as dose of ephedrine)
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	Method not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Blinding not mentioned
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Apgar scores were blinded – no further details
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Losses to follow‐up: 2/28 women were excluded due to technical difficulties with the ephedrine infusion pump and the Dinamap respectively
Selective reporting (reporting bias)	Unclear risk	Unclear reporting
Other bias	Unclear risk	unclear reporting