Nishikawa 2007.

Study characteristics
Methods	RCT
Participants	54 women Inclusion criteria: ASA I‐II status women, between 20 to 40 years, undergoing elective caesarean Exclusion criteria: women with BMI > 30 kg/m², anaemia (Hb < 10 g/dL), history of neurological or psychiatric diseases Setting: Japan
Interventions	Colloid preload versus colloid coload versus crystalloid alone Group 1: colloid preload: after Ringer's lactate was started at a rate of 5 mL/kg, this was changed to HES 6% (molecular weight 70 kDa, degree of substitution 0.5) and infusion rate was increased to 15 mL/kg for 10 min before spinal anaesthesia. Infusion rate was returned to Ringer's lactate at 5 mL/kg Group 2: colloid coload: after Ringer's lactate was started at a rate of 5 mL/kg, this was changed to HES 6% (molecular weight 70 kDa, degree of substitution 0.5) and infusion rate was increased to 15 mL/kg for 10 min after spinal anaesthesia. Infusion rate was returned to Ringer's lactate at 5 mL/kg Group 3: crystalloid alone: Ringer's lactate at 5 mL/kg All women received standardised leg wrapping, no sedative premedication, and a standardised spinal anaesthetic technique and dose. Hypotension requiring intervention was managed with IV bolus of 4 mg of ephedrine to maintain BP at 80% of baseline. Bradycardia was managed with IV atropine 0.5 mg.
Outcomes	Maternal: hypotension; need for ephedrine; BP; bradycardia Neonatal: pH, BE, Apgar scores
Notes	Hypotension was defined as a decrease in SBP < 80% baseline Bradycardia was defined as heart rate < 50 bpm
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number tables
Allocation concealment (selection bias)	Unclear risk	No method of allocation concealment reported
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Double‐blind"; "both the patient and the researcher who recorded the data were blinded as to the type of colloid loading"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	No losses to follow‐up
Selective reporting (reporting bias)	Low risk	Most expected outcomes were reported (except for nausea/vomiting)
Other bias	Unclear risk	Similar baseline characteristics except that women in the HES coload group had lower mean BMI