Cerebral Vasopasm (PART 2)

TREATMENT : Pharmacologic treatment:(1,4) Numerous drugs have been investigated for prevention or treatment vasospasm but most are ineffective. Calcium channel blockers (calcium antagonist) which nimodipine has been more extensively studied are the only drugs that have been shown to consistently reduce the mortality and morbidity from vasospasm in all patients with SAH irrespective of the grades.  Nimodipine, a dehydropyridine calcium antagonist blocks the intracellular influx of extra cellular calcium, preventing arterial smooth muscle contraction. It was initially believed that this agent prevents constriction of vessels; however clinical trial have...

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Cerebral Vasopasm (PART I )

DEFINITION : (2,3,4) Vasospasm is the prolonged intense constriction of the larger conduction arteries in the subarachnoid space,which initially surrounded by subarachnoid clot it is likely that spasmogens are released from the breakdown of red blood cell trapped by fibrin mesh in in the the abnormal environment of subarachnoid space.The etiology remain uncertain but appears to be related to the amount and distribution of blood in the subarachnoid space. This may also be due to local mechanic pressure effects from the high pressure arterial bleeding of the aneurysm or from the clot itself. Pathogenesis :(1,3) The vasospastic artery has a structural and pathologic changes...

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Subarachnoid Hemmorhage And Anesthetic Consideration (PART 5)

HYPERTENSIVE HYPERVOLEMIC HEMODILUTION (TRIPLE H):(1,3) Since perfusion depends in part on the intravascular volume and MAP the boosting of CBF as accomplished by Triple H therapy or hypertensive hypervolemic hemodilution. The augmentation of blood pressure and the expansion of intravascular volume, the preservation of relative hemodilution (hematocriet of 32%) to promote blood flow through the cerebral microvasculature and the avoidance of hyponatremia.The key to the succesful use of Triple H therapy is its early application before mild ischemia evolves to infarction. Because the risk of rebleeding can be as high as 19%, however,both hypertensive and hypervolemia...

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