Gunusen 2010.

Study characteristics
Methods	RCT
Participants	120 women Inclusion criteria: healthy women aged 20‐40 years scheduled for elective caesarean delivery under spinal anaesthesia who had uncomplicated singleton, term pregnancy Exclusion criteria: chronic or pregnancy‐induced hypertension, cardiac disease, diabetes mellitus, height < 155 cm, a contraindication to spinal anaesthesia, or known fetal abnormality Setting: Turkey
Interventions	Colloid preload versus crystalloid preload versus ephedrine infusion plus crystalloid co‐load Group 1: crystalloid preload: rapid infusion of Ringer's lactate 20 mL/kg, within 15‐20 min of the spinal block. Following anaesthesia, placebo infusion solution administered at a rate of 2.5 mL/min using an infusion pump. Ringer's lactate 1000 mL administered at minimal maintenance rate via 2nd cannula Group 2: colloid preload: 4% succinated gelatine solution (Gelofusine) 500 mL, within 15‐20 min of the spinal block Following anaesthesia, placebo infusion solution administered at a rate of 2.5 mL/min using an infusion pump. Ringer's lactate 1000 mL administered at minimal maintenance rate via 2nd cannula Group 3: ephedrine infusion plus crystalloid co‐load: no fluid preload given Following anaesthesia, infusion solution of ephedrine 50 mg in 100 mL (1.25 mg/mL) administered at rate of 2.5 mL/min using an infusion pump. Ringer's lactate1000 mL, administered rapidly via 2nd cannula All women received standardised aspiration prophylaxis, a standardised spinal anaesthetic technique and dose, standardised surgical positioning and standardised oxytocin administration. Hypotension (requiring intervention) was treated immediately with an IV bolus of ephedrine 5 mg from a separate syringe, repeated when necessary, every 2 min if hypotension persisted or recurred Hypertension treatment: infusion was stopped if the SBP and heart rate increased above the baseline values Bradycardia treatment consisted of IV atropine 0.5 mg.
Outcomes	Maternal: moderate hypotension; severe hypotension; maternal bradycardia requiring intervention; maternal tachycardia; hypertension; nausea and vomiting Neonatal: acidosis (cord/neonatal blood with pH < 7.2); neonatal Apgar score < 8 at 5 min
Notes	Moderate hypotension was defined as a decrease of 20% from baseline, or an SBP < 95 mmHg. Severe hypotension was defined as a decrease of 30% from baseline. Bradycardia was defined as heart rate < 50 bpm. Tachycardia was defined heart rate > 120 bpm. Hypertension was defined as an increase in SBP > 30% above baseline.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation list
Allocation concealment (selection bias)	Unclear risk	"Randomly allocated" – concealment method not specified
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Pre‐load fluid in groups CO and CR was administered by an anaesthetic nurse who was not otherwise involved in the care of the patients. Co‐load fluids were prepared by an anaesthetic nurse who was independent of the study. Ringer's lactate in all groups were covered by a similar non‐transparent plastic bag in the perioperative period.  The anaesthetist did not enter the operating room until the study solutions had been given, so that those recording data were unaware of the study group allocation.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"Those recording data were unaware of the study group allocation." Attending paediatrician assessed Apgar scores – unclear if blinded to allocated treatment Umbilical blood samples were taken by the same midwife in the operating room – likely to have been blinded to allocated treatment
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	1/120 – 1 patient in crystalloid preload group was excluded from the study due to an inadequate spinal block
Selective reporting (reporting bias)	Low risk	None apparent
Other bias	Low risk	None apparent