Prophylactic magnesium sulfate for aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis.

Delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage is a cause of considerable morbidity and mortality. Magnesium sulfate has been proposed as a prophylactic intervention for angiographic vasospasm and to improve clinical outcomes. A systematic review was conducted to determine the evidence for the prophylactic use of magnesium sulfate in aneurysmal subarachnoid hemorrhage. Medline, Embase, Cochrane library, clinicaltrials.gov, and controlled-trials.com were searched with a comprehensive search strategy. 2,035 records were identified in the initial search and 1,574 remained after removal of duplicates. Randomized, parallel group, controlled trials of magnesium sulfate in patients with aneurysmal subarachnoid hemorrhage were included. A total of ten studies were included. Review Manager and GRADE software were used to synthesize the results. The summary effect for Glasgow outcome scale and the modified Rankin scale is a risk ratio (RR) of 0.93 [95 % confidence interval (CI) 0.82-1.06]. The RR for mortality is 0.95 [95 % CI 0.76-1.17]. Delayed cerebral ischemia has a RR of 0.54 [95 % CI 0.38-0.75], which is the only outcome with a statistically significant summary effect measure favoring magnesium treatment. Delayed ischemic neurological deficit has a RR of 0.93 [95 % CI 0.62-1.39]. Transcranial doppler vasospasm has a RR of 0.72 [95 % CI 0.51-1.03]. Current evidence does not support the prophylactic use of magnesium sulfate in aneurysmal subarachnoid hemorrhage.