Cerebral Aneurysm Surgery Flashcards
Increase in ICP due to aneurysm (effect of hemorrhage and edema) leads to:
Headache
loss of consciousness
possible motor deficits
Rising ICP can lead to which reflex?
Cushings-defined by hypertension, bradycardia and (irregular respirations)
Rebleeding after aneurysm surgery-when is it most common?
First day!
What is TCD? what are its indications?
Its a direct and non-invasive monitor of CBF
Indications:
Determine severity of cerebral vasospasm
Measure CBF during carotid artery clamping in carotid endarterectomy
Detection of emboli after arterial repair or during CPB
What are the Hunt and Hess classifications of patients with SAH?
0-unruptured aneurysm
1-asymptomatic or minimal headache and slight nuchal rigidity
2-mod-severe headache, nuchal rigidity, no other neurologic deficit than cranial nerve palsy
3-drowsiness, confusion, or mild focal deficit
4-stupor, early decerebration, moderate to severe hemiparesis
5-deep coma, decerebrate rigidity
What is neurogenic pulmonary edema? How do you treat it?
Occurs due to sympathetic activation secondary to the rise in ICP leading to pulmonary and systemic vasoconstriction. This increases pulmonary blood volume, and causes a rise in pulmonary capillary permeability
Treat it with immediate surgical or pharmacologic relief of intracranial hypertension, careful fluid management.
Cardiac dysrhythmias and EKG abnormalities during SAH: why? What does it correlate with? How would it look?
Due to excessive catecholamine release triggered by SAH. it correlates with degree of neurologic injury rather than cardiac dysfunction. Will likely have deep wide splayed T wave inversions, long QT, prominent U wave.
Remember to rule out hypotension-as a reason for dysthymia, supply patient wit O2 if you think its necessary
What electrolyte abnormalities are you expecting with SAH?
Hyponatremia due to SIADH or CSW
Other electrolyte abnormalities such as hypokalemia, hypocalemia, and hypomagnesemia may occur secondary to diuretic therapy in an attempt to lower ICP with loop or osmotic diuretics.
Intraoperatively, How are you trying to induce-what do you want to minimize? how? are its considered full stomach? Induction agent of choice? Other options?
Blunt sympathetic response with IV fentanyl (3 mcg/kg) and IV lidocaine (1.5 mg/kg) Pre-treat with VEC 0.01 mg/kg to prevent associated response of increased ICP (THESE PATIENTS SHOULD BE TREATED AS FULL STOMACH)
Etomidate is induction agent of choice 2/2 hemodynamic stability and decreasing effect on ICP
Thiopental has cerebroprotective effects and can be used, but should be titrated carefully due to its potential to cause hypotension.
IV access in cerebral aneurysm/SAH?
At least two large bore IV catheters
Monitors during SAH?
CVP can be used for guidance of intravascular volumes in the face of severe cardiac instability
What do you want to avoid intraop? Overall goal for intra-op mgmt?
Avoid HTN and resultant aneurysmal rupture.
Ultimate goals for the surgery: avoid aneurysm rupture, maintain cerebral perfusion pressure
Would you want neuromonitoring?
it could be beneficial in areas potentially affected by the aneurysm clipping.
Postoperative goals at emergence:
Who are you extubating?
avoid coughing, straining, hypercarbia, and hypertension as these will lead to an increase in ICP
Extubation: Those who were Hunt-Hess grades 1 and 2 prep with no intra-op complications
Those who came with altered mental status are going to ICU intubated as well as those who are hemodynamically unstable and/or had a hemorrhage event intra-operatively
What do you want to avoid post op?
Extremes. Hypertension (extreme) can lead to cerebral edema or hematoma, leading to increased ICP and vasospasm
Hypotension-decreased BP can cause decreased cerebral perfusion pressure
What is formula for Cerebral perfusion pressure?
CPP= MAP-ICP