Vasospasm worsen outcome in patients with aneurysmal subarachnoid hemorrhage (ASAH).~Magnesium is known to dilate cerebral arteries and to block N-methyl-D-aspartate receptors in the injured neurons.~Intravenous magnesium may prevent vasospasm after subarachnoid hemorrhage and may protect neurons against damage during established vasospasm.~The IMASH trial is a randomized, placebo-controlled, double-blinded, multi-center trial to evaluate the effect that intravenous magnesium sulfate infusion on the clinical outcome of patients with aneurysmal subarachnoid haemorrhage.~Methods:~After obtaining randomisation code:~Start MgSO4 20 mmol over 30 minutes, followed by infusion of 80 mmol/day or equivalent volume of saline within 48 h after onset of symptom,~Study drug to be infused for 14 days from the day of hemorrhage (regarded as day 0).~Measure plasma magnesium concentration daily and perform transcranial Doppler to monitor blood flow velocities of both middle cerebral arteries and extracranial segment of the internal carotid arteries.~Plasma magnesium concentration in the IV MgSO4 group should be raised to 2.0-2.5 mmol/L or twice the serum baseline level. Patients that are randomized to saline infusion will only have their magnesium levels normalized if there is a clinical indication to do so.~Outcome assessment Primary outcome: Extended Glasgow Outcome Scale at six months Secondary outcome: Incidence of clinical vasospasm, Barthel Index; modified Rankin score, modified National Institute of Health Stroke Score, MCA velocities, other major complications~Study duration:~6 years with a refined sample size of 340 after analysis of pilot study data; with planned interim analysis.
The IMASH trial is a simple, randomized, double-blinded, placebo-controlled, multi-center trial to answer the question: Does intravenous magnesium sulfate improve clinical outcome after aneurysmal subarachnoid hemorrhage?