Intracranial and cerebrovascular disease Flashcards
Cerebral ischemia develops, and neurologic damage will ensue if the underlying process is not corrected within __ to __ minutes.
3 to 8
This refers to global hypoxia (respiratory failure, asphyxia) or circulatory arrest wherein the brain is not perfused.
Global ischemia
This can result from vasospasm, traumatic, hemorrhagic, embolic, or atherosclerotic events.
Focal ischemia
A third group of patients experience neurologic dysfunction for longer than 24 hours, with spontaneous and complete recovery within 1 to 2 weeks. This phenomenon is termed?
Reversible ischemic neurologic deficit
Atherosclerosis located where is the source of most cerebral ischemic events.
Bifurcation of the common carotid artery
What are the two most important risk factors for cerebral ischemia?
Hypertension and cigarette smoking
Cerebral autoregulation is functioning at what cerebral pressures?
50 to 150 mmHg
Normal cerebral blood flow in humans is ___ and how much CO does it go to the brain?
40 to 60 mL/100 gm/min
15% of CO
The cerebral metabolic rate for oxygen in adults is?
3-4 mL/100 gm/min
20% of whole body compsumption
The cerebral blood flow at which ischemia becomes apparent on electroencephalogram (EEG), is termed as the?
Critical regional cerebral blood flow
18 to 20 mL/100 gm/min
20% of rebleeding of aneurysms mostly occur within how long post op?
Within 2 weeks
Highest risk post op day 1
The etiology is believed to be subarachnoid blood around the circle of Willis in the basal cisterns.
Vasospasm is most clearly demonstrated by angiography and involves the ______ artery 75% of the time.
Middle cerebral
Describe the treatment options if vasospasm is suspected following an spontaneous subarachnoid hemorrhage.
Hypervolemia is achieved with ______ administration, with a goal of central venous pressure of __ to __ mm Hg or pulmonary artery wedge pressure of __ to __ mm Hg.
Colloid
8-12 mmHg
18 to 20 mmHg
The desired level is a hematocrit of ___ to ___, thereby reducing viscosity and improving microcirculation.
27 to 30
If the aneurysm is clipped, vasopressors (dopamine, phenylephrine) can be used to induce hypertension, with the goal being a mean arterial pressure approximately ____to ___ mm Hg greater than baseline systolic pressure.
20 to 30
The key to SAH management is early diagnosis and surgical treatment within ___ hours. Vasospasm should be treated with HHH therapy.
72
Glucose must be maintained between __ to __ mg/dl to prevent further neurologic insult.
80 to 120
Neurosurgeons commonly place temporary occlusion clips on the parent artery that feeds the aneurysm before clipping it. Most studies have shown that this is tolerated for __ to __ minutes.
10 to 14
The risk of ischemic injury increases up until __ minutes of temporary clipping, at which time the chance
of ischemic insult is nearly 100%.
31
This phenomenon of cerebral edema is also called?
Autoregulation breakthrough
