Magnesium Levels and Diastolic Blood Pressure (DBP) as a Vasospasm Prediction Metric in Patients With Aneurysmal Subarachnoid Hemorrhage (SAH)

Introduction Vasospasm is a significant cause of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study is to evaluate a possible link between vasospasm in patients with aneurysmal SAH and magnesium and blood pressure levels. Methods Subjects were selected based on chart review of patients presenting to a comprehensive stroke center in Southern California with aneurysmal SAH. 27 were included based on the following criteria: patients greater than 18 years of age, aneurysmal SAH, clinically symptomatic vasospasms and at least one diagnostic confirmation - either from a transcranial doppler (TCD) or digital subtraction angiogram (DSA). The following exclusion criteria also applied: 1) incomplete documentation in the medical record; 2) patients <18 years of age; and 3) patients without TCD measurements. Results In an overall analysis of all patients with or without vasospasm, it was found that the presence of vasospasm was significantly correlated with diastolic blood pressures (DBPs) on day of vasospasm with an r value of 0.418 and p<0.001. Average daily DBPs throughout hospital stay were also correlated with vasospasm with an r-value of 0.455 and p<0.001. Changes in magnesium overall were also significantly related to left Lindegaard ratios with an r value of -0.201 and p value of 0.032. Lindegaard ratios were significantly correlated with age with r values of 0.510, p<0.001, and r=-0.482, p<0.001 for left and right, respectively. A change in magnesium was inversely correlated to the left Lindegaard ratio with an n of 31 and p value of 0.014 (r= -0.439) in patients with vasospasm. We also found a lower incidence of vasospasm in patients older than 65. Conclusion Monitoring magnesium and increases in DBP might be effective as a prophylactic adjunct method in patients with SAH in an effort to predict clinical vasospasm.