Singh 2009.

Study characteristics
Methods	Randomised, quasi‐experimental observational cohort study
Participants	60 patients Inclusion criteria: ASA I, elective LSCS Exclusion criteria: pregnancy‐induced high BP, high‐risk pregnancy, fetal distress, moderate to severe anaemia, patient refusal, infection at site of injection, bleeding diathesis, severe hypovolaemia, elevated intracranial pressure, spine deformity and patients with major systemic illness Setting: India
Interventions	Crystalloid versus colloid preload Group 1: 20 mL/kg Ringer's lactate preloading over 20 min just prior to SAB Group 2: 10 mL/kg HES 130/0.4 (up to a max 500 mL) preloading over 20 min just prior to SAB All women received standardised premedication, positioning, monitoring, IV cannulation/urinary catheter, SAB and technique, oxygen delivery, intra‐operative fluids, oxytocin. Hypotension treated with IV bolus of crystalloid up to 200 mL, further hypotension treated with mephentermine 3 mg IV bolus every 1 min until SBP> 90 mmHg achieved. Bradycardia treated with atropine 300 μg aliquots.
Outcomes	Maternal: haemodynamics/observations, urine output, duration of surgery, uterine incision‐delivery time, SAB complications, "undesirable effects" from HES including "anaphylactoid" reactions, pruritis, bleeding Neonatal: Apgar scores at 1 min and 5 min
Notes	Hypotension was defined as a fall in SAP > 30% of baseline or SAP < 90 mmHg
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
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	Unclear risk	Not reported
Selective reporting (reporting bias)	Unclear risk	Not reported
Other bias	Unclear risk	Not reported