There are insufficient data on pharmacological strate- gies and induced hypertension during temporary ves- sel occlusion to make specific recommendations, but there are instances when their use may be considered reasonable (Class IIb; Level of Evidence C). 3. Induced hypothermia during aneurysm surgery is not routinely recommended but may be a reasonable op- tion in selected cases (Class III; Level of Evidence B). 4. Prevention of intraoperative hyperglycemia during aneurysm surgery is probably indicated (Class IIa; Level of Evidence B). 5. The use of general anesthesia during endovascular treatment of ruptured cerebral aneurysms can be beneficial in selected patients (Class IIa; Level of Evidence C). Management of Cerebral Vasospasm and DCI After aSAH Narrowing (vasospasm) of the angiographically visible cere- bral arteries after aSAH is common, occurring most fre- quently 7 to 10 days after aneurysm rupture and resolving spontaneously after 21 days. The cascade of events culminat- ing in arterial narrowing is initiated when oxyhemoglobin comes in contact with the abluminal side of the vessel.205 The pathways leading to arterial narrowing have been the focus of extensive basic research, but no effective preventive therapy has been developed to date. Part of the reason for this lack of success likely stems from the fact that vasospasm occurs at multiple levels in the arterial and arteriolar circulation. 