Intra-arterial nitroprusside treatment of acute experimental vasospasm.

The effect of intra-arterial sodium nitroprusside infusions on acute experimental basilar artery spasm was studied in dogs. Vasospasm produced by subarachnoid hemorrhage at normal intracranial pressure was partially relieved by nitroprusside. When given by the intra-arterial route, 15 times the recommended maximum intravenous does can be infused without significant hypotension or elevation in intracranial pressure.