Prolonged, profound hypotension produced safely with sodium nitroprusside.

Nine and one-fourth hours of profound hypotension were necessary to accomplish the successful removal of a large arteriovenous malformation from the medial portion of the dominant parietal lobe. The hypotensive agent used was sodium nitroprusside. The removal was associated with a minimal neurological deficit. This is the longest known use of sodium nitroprusside for deliberate hypotension during surgery which emphasizes the safety of this hypotensive technique, provided the total dosage of sodium nitroprusside is reasonable.