Cerebral blood flow velocity response to magnesium sulfate in patients after subarachnoid hemorrhage.
Magnesium sulfate therapy, standard in preventing seizures in preeclampsia, is under active investigation as a neuroprotective agent. The authors studied the effect of magnesium as a cerebral vasodilator by measuring the cerebral blood flow velocity (CBFV) response to a 5g intravenous bolus of MgSO4 compared with a saline placebo after subarachnoid hemorrhage (SAH). Transcranial Doppler ultrasonography of the middle cerebral artery (MCA) was measured after each infusion. Patients were studied up to three times after SAH at prescribed time intervals. Fourteen patients (11 women, 3 men; mean age 58 years) underwent 29 studies. All patients underwent hypertensive, hypervolemic therapy. Four patients developed cerebral vasospasm. Doubling serum magnesium levels did not affect MCA CBFV but slightly lowered mean arterial blood pressure and systemic vascular resistance. Intravenous magnesium bolus did not reduce elevated CBFV in the subset of SAH patients with clinical vasospasm. The role of magnesium sulfate as a cerebral vasodilator in patients with SAH requires further study.
Brewer
R P
RP
Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA.
Parra
A
A
Lynch
J
J
Chilukuri
V
V
Borel
C O
CO
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000927:Anticonvulsants / Q000627:therapeutic use*; D001783:Blood Flow Velocity / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000209:etiology / Q000601:surgery*; D008278:Magnesium Sulfate / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000187:drug effects; D010919:Placebos; D011183:Postoperative Complications; D011651:Pulmonary Artery; D013345:Subarachnoid Hemorrhage / Q000188:drug therapy / Q000503:physiopathology* / Q000601:surgery*; D017585:Ultrasonography, Doppler, Transcranial; D014655:Vascular Resistance / Q000187:drug effects; D020301:Vasospasm, Intracranial / Q000209:etiology
D000927:Anticonvulsants; D010919:Placebos; D008278:Magnesium Sulfate