Randomised controlled trials (RCTs) that investigated the effect of magnesium sulphate in patients with subarachnoid haemorrhage were eligible for inclusion. There were no restrictions for magnesium sulphate dose, route of administration, or duration of treatment.
The primary outcomes were: poor outcome (death, vegetative state, or severe disability) or a a favorable outcome (moderate disability and good recovery); mortality was assessed as a secondary outcome. Outcomes were measured three months after aneurysmal subarachnoid haemorrhage using the Glasgow Outcome Scale score or the modified Rankin Scale.
In all included trials, magnesium sulphate was administered through continuous intravenous infusion at doses ranging from 24 to 144mmol/day; the target level of serum magnesium ranged from 1.0 to 2.3mmol/L (where reported). Administration of magnesium sulphate ranged from verification of subarachnoid haemorrhage to within five days of subarachnoid haemorrhage and lasted for 10 to 18 days; in one trial magnesium sulphate was administered until intensive care unit discharge. The mean age of participants ranged from 46 to 58.9 years.
The authors did not state how relevant studies were selected for the review.