Effect of Sevoflurane on vasospastic cerebral vasculature following aneurysmal sah, in patients receiving intra- arterial nimodipine, assessed by digital subtraction angiography :a prospective randomized controlled trial(SIAN-VCV trial)

subarachnoid hemorrhage following rupture of cerebral aneurysm is a life-threatening condition. Who survive many of them suffer from severe neurological and neurocognitive deficits. One of the most dangerous consequences of aneurysmal subarachnoid hemorrhage is cerebral vasospasm described as reversible constriction of cerebral blood vessels, mostly affecting major vessels of circle of  Willis . The effectiveness of oral and intra-arterial nimodipine in preventing and treating cerebral vasospasm and decreasing cerebral infraction is well established. Sevoflurane is a cerebral vasodilator. Digital subtraction angiography is a method by which direct vessel can be measured using electronic caliper. Previous study showed that effects of propofol and sevoflurane on cerebral vasculature in patients with aneurysmal subarachnoid hemorrhage using digital subtraction angiography and observed that sevoflurane has vasodilating properties compared to propofol in patients with aneurysmal subarachnoid hemorrhage

Hypothesis is that sevoflurane has synergistic effect of vasodilation with that of intra-arterial nimodipine in patients with cerebral vasospasm following aneurysmal subarachnoid hemorrhage. The mean change in vascular diameter  from baseline during  nimodipine therapy will be greater under sevoflurane anesthesia than under propofol based anesthesia in patients presenting for intra-arterial nimodipine therapy for vasospasm following aneurysmal subarachnoid hemorrhage.