Prophylactic magnesium for improving neurologic outcome after aneurysmal subarachnoid hemorrhage: Systematic review and meta-analysis

PurposeNeurologic disability is common after aneurysmal subarachnoid hemorrhage (aSAH). Our objective was to systematically review the prophylactic use of magnesium to improve neurologic outcomes in these patients.MethodsWe searched MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials to June 2012 for randomized and quasi-randomized controlled trials of intravenous magnesium in adults after aSAH, given before radiologic vasospasm or delayed cerebral ischemia (DCI) and compared with any control group. Two reviewers independently extracted data on study population, interventions, and outcomes (good neurologic outcome [primary outcome], cerebral infarction, DCI, radiographic vasospasm, mortality, adverse events). Analyses used random-effects models.ResultsOf 702 citations, 13 trials (n = 2401) met the selection criteria. Meta-analyses showed that magnesium did not increase the probability of good neurologic outcome (risk ratio [RR], 1.02; 95% confidence interval [CI], 0.97-1.07; P = .49; 12 trials, n = 2345) or decrease the risks of cerebral infarction (RR, 0.69; 95% CI, 0.46-1.05; P = .08; 5 trials, n = 572), radiographic vasospasm (RR, 0.86; 95% CI, 0.71-1.04; P = .13; 7 trials, n = 438), or mortality (RR, 0.98; 95% CI, 0.80-1.20; P = .86; 11 trials, n = 2092). Magnesium did reduce the risk of DCI (RR, 0.73; 95% CI, 0.56-0.96; P = .02; 10 trials, n = 1095). Data on adverse events were generally sparse.ConclusionsDespite decreasing the incidence of DCI in patients with aSAH, prophylactic intravenous magnesium does not improve neurologic outcome or decrease cerebral infarction, radiographic vasospasm, or mortality.