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Magnesium use on prophylaxis of vasospasm morbidity and mortality rate in subarachnoid hemorrhage


Cerebral aneurysms are an important cause of morbidity and mortality of which the most severe consequence is their rupture. Subarachnoid hemorrhage (SAH) has arterial vasospasm as one of the most serious complications.


After institutional approval and informed consent, a prospective, randomized, single-blind study was carried out between February 2008 and November 2009. The study evaluated Mg use on patients from Beds 1 to 4 and the control group from Beds 5 to 8. The serum measure of Mg was made by colorimetric method in order to reach a measurement between 2.5 and 3.5 mg/dl, using a solution of Mg 2% (SG 5%, 400 ml + MgSO4 10%, 100 ml/24 hours), during the first 14 days of the event (aneurysm rupture). Admission criteria: patients diagnosed with SAH confirmed by CT or cerebral angiography and Δt <96 hours. Exclusion criteria: patients with SAH and ΔT >96 hours; patients who presented a vasospasm episode in less than 24 hours of Mg solution infusion.


In a previous study evaluation a total of 107 patients were analysed with n = 55 in Group 1 and n = 52 in Group 2 (Figures 1 and 2). The main results were: Group 1 - vasospasm frequency 20.0%, confidence interval (CI) = 10.4% to 33.3%; and mortality 16.4% in 28 days, CI = 7.8% to 28.8; Group 2 - vasospasm frequency 51.9%, CI = 37.6% to 66.0%; and mortality 23.1% in 28 days, CI = 12.5% to 36.8%. The analysis for the vasospasm showed odds ratio (OR) = 0.23, CI = 0.098% to 0.544% and P = 0.0011, and for mortality: OR = 0.65, CI = 0.24% to 1.70% and P = 0.5284.


Figure 1


Figure 2


According to the outcome, we can conclude that Group 1 obtained a greater protection on the vasospasm incidence in comparison with Group 2 but showed no difference in mortality. The P value was significant for vasospasm but was still not significant for mortality.


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Correspondence to S Kiffer Macedo.

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Macedo, S.K., de Siqueira, C.P., de Siqueira, S.B.P. et al. Magnesium use on prophylaxis of vasospasm morbidity and mortality rate in subarachnoid hemorrhage. Crit Care 14, P344 (2010).

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  • Confidence Interval
  • Magnesium
  • MgSO4
  • Subarachnoid Hemorrhage
  • Study Evaluation