Mohta 2010.

Study characteristics
Methods	RCT
Participants	60 women Inclusion criteria: ASA I or II women with term uncomplicated pregnancies, scheduled to undergo elective CS under subarachnoid block Exclusion criteria: pregnancy‐induced hypertension, cardiovascular disease, cerebrovascular disease, placental or fetal abnormalities, absolute or relative contraindication to spinal anaesthesia and women with SBP < 100 mmHg Setting: India
Interventions	Phenylephrine versus mephentermine Group 1: infusion of phenylephrine (50 μg/mL); administered immediately following spinal anaesthesia, at a rate of 60 mL/h (50 μg/min) Group 2: infusion of mephentermine s (600 μg/mL); administered immediately following spinal anaesthesia, at a rate of 60 mL/h (600 μg/min) All women received a standardised fluid preload and standardised spinal anaesthetic technique. Spinal anaesthetic dose was 2.2 mL of hyperbaric 0.5% bupivacaine unless patient's height was < 150 cm, in which case the dose was 2 mL. Hypotension was managed with a 2 mL bolus dose of respective vasopressor solution (100 μg phenylephrine or 1.2 mg mephentermine). Hypertension was managed with stepwise reduction in infusion by 6 mL/h. Bradycardia was managed with 0.3 mg boluses of atropine.
Outcomes	Maternal: hypotension; reactive hypertension; bradycardia; nausea; vomiting; dizziness Neonatal: umbilical arterial and venous blood gases; Apgar scores at 1 min and 5 min
Notes	Hypotension was defined as fall of ≥ 20% from baseline or an absolute value of < 100 mmHg SBP, whichever was higher. Hypertension was defined as a rise in SBP > 20% above baseline. Bradycardia was defined as heart rate < 50 bpm
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomly divided into two groups of 30 each"
Allocation concealment (selection bias)	Unclear risk	"Sealed envelope"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Described as double‐blind: "the solution of vasopressor for infusion was prepared by an assistant who was not involved in the study, and the investigator, as well as the patient, were thus blinded to the identity of vasopressor used" However, it was not possible for the anaesthetist to be blinded as treatment of hypotension with "the respective vasopressor solution" would have required knowledge of which vasopressor was used.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	As above
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
Other bias	Low risk	Similar baseline characteristics except for a lower mean baseline heart rate in the phenylephrine group