Loke 2002.

Study characteristics
Methods	RCT
Participants	40 women Inclusion criteria: ASA I women presenting for elective caesarean under spinal anaesthesia
Interventions	Head‐down tilt versus control: Group 1: anaesthesia induced in right lateral position (woman's spine inclined at 5 to 6 degrees from horizontal with head slightly lower); anaesthesia induced in right lateral position 10 degree head‐up tilt Group 2: anaesthesia induced in right lateral position (woman's spine inclined at 4 to 5 degrees from horizontal with head slightly higher). All women received a standardised preload of 1 litre crystalloid IV and a standardised spinal anaesthetic technique and dose.
Outcomes	Maternal: hypotension; sensory block; ephedrine requirement; nausea; pain Neonatal: Apgar scores at 1 min and 5 min
Notes	Hypotension defined as SBP < 90 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	"Sealed envelope method"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not mentioned
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding: outcome assessors were only admitted to the operating room once the position of the operating table had been readjusted
Incomplete outcome data (attrition bias) All outcomes	Low risk	Losses to follow‐up: none reported but losses unlikely
Selective reporting (reporting bias)	Low risk	None apparent
Other bias	Low risk	None apparent