Bottiger 2010.

Study characteristics
Methods	RCT
Participants	60 women Inclusion criteria: ASA I/II, elective caesarean delivery Exclusion criteria: none stated Setting: USA
Interventions	Crystalloid preload versus colloid preload Group 1: crystalloid preload (1500 mL Ringer's lactate) Group 2: colloid preload (0.5L 6% HES) Women in both groups received 100 μg/min phenylephrine infusion following spinal anaesthesia which continued until uterine incision. The phenylephrine infusion was adjusted according to heart rate and SBP which was maintained at 20% of the baseline. No further information regarding spinal anaesthetic technique/dose etc was provided.
Outcomes	Maternal: vasopressor dose, incidence of hypotension, incidence of nausea and vomiting, incidence of bradycardia Neonatal: Apgar score
Notes	Hypotension was defined as a 20% fall in SBP from baseline. Hypertension was defined as an increase of 20% from baseline.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Method not explicitly stated
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	3 women excluded for unspecified reasons and at an unclear point along the study pathway Additionally, study states "60 patients were included as part of a 90 patient study"
Selective reporting (reporting bias)	Low risk	None evident
Other bias	Low risk	None evident