Ngan Kee 2004a.

Study characteristics
Methods	RCT
Participants	50 women Inclusion criteria: term singleton pregnancies scheduled for elective caesarean under spinal anaesthesia Exclusion criteria: pre‐existing or pregnancy‐induced hypertension, cardiovascular or cerebrovascular disease, known fetal abnormality or contraindication to spinal anaesthesia Setting: Hong Kong, China
Interventions	Phenylephrine versus control Group 1: phenylephrine IV immediately after intrathecal injection; 100 µg/min for 3 min Group 2: control (saline infusion plus rescue IV bolus of phenylephrine (100 µg) when SAP < 80% baseline Note: women in the phenylephrine group were given phenylephrine 100 µg/min whenever SAP was less than baseline. All women received a standardised spinal anaesthetic technique and dose.
Outcomes	Maternal: hypotension; BP; nausea and vomiting; bradycardia requiring intervention; phenylephrine dose; incision to birth time Neonatal: umbilical arterial blood gases; umbilical venous blood gases; Apgar scores
Notes	Hypotension defined as SAP < 80% baseline
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Computer‐generated randomization codes"
Allocation concealment (selection bias)	Low risk	"Codes contained in sealed, sequentially numbered envelopes"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Double blind"; "two identical syringes"; investigators and women were blinded to the contents of the syringes
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	As above
Incomplete outcome data (attrition bias) All outcomes	Low risk	Losses to follow‐up: none (although there was insufficient cord blood to measure pH in 1 neonate)
Selective reporting (reporting bias)	Low risk	Appears to report all
Other bias	Low risk	None evident