gms | German Medical Science

Objective: Increasing evidence suggests that SAH-patients benefit from intravenous magnesium treatment. We recently showed that magnesium sulfate can attenuate delayed vasospasm and increase the ischemic tolerance in case of cerebral vasospasm and perfusion deficits. However, a number of patients still developed vasospasm, infarction and delayed neurological deficits. This analysis covers the side effects and the serum/CSF-distribution during intravenous magnesium treatment.

Methods: A total of 107 patients was analyzed. 54 patients received magnesium, 53 served as controls. Serum electrolytes and creatinine were measured 3 times a day, CSF electrolytes and urine electrolytes were determined once a day. In all patients, invasive measurement of blood pressure, heart rate and central venous pressure was performed.

Results: While elevated serum magnesium levels were continuously maintained between 2.0 and 2.5 mmol/l in the magnesium-group (vs. 0.87±0.07 mmol/l in controls), CSF concentrations remained distinctly lower (1.52±0.19 mmol/l vs. 1.20±0.12 mmol/l in controls). In magnesium-treated patients, significant hypocalcemia and elevation in serum creatinine relative to control patients was observed. Mean arterial blood pressure and the amount of catecholamines administered to meet the individual blood pressure targets did not differ between the two groups. In magnesium-treated patients a significantly lower heart-rate was observed, but in no patient necessitated the exclusion from the study.

Conclusions: Intravenous magnesium-treatment proved to be safe and effective for patients suffering from aneurysmal SAH. Preexisting bradycardia and atrioventricular block of any degree should be an exclusion criteria for intravenous magnesium-treatment as well as an elevation of serum creatinine values. An elevation of magnesium serum concentrations above 2.5 mmol/l seems possible but should be performed under close cardiovascular surveillance. With respect to the potential hazards of very high serum-levels, a further elevation of CSF concentrations might be best performed by the intrathecal route.