130 likes | 498 Views
Anesthetic Goals for cerebral aneurysm. Lindsay Attaway MD. Intracranial aneurysms. Arise in Circle of Willis Mostly in anterior circulation Rupture and SAH greatest concern Account for 75-80% of SAH 1/3 die from initial bleed 1/3 severe disability/delayed death
E N D
Anesthetic Goals for cerebral aneurysm Lindsay Attaway MD
Intracranial aneurysms • Arise in Circle of Willis • Mostly in anterior circulation • Rupture and SAH greatest concern • Account for 75-80% of SAH • 1/3 die from initial bleed • 1/3 severe disability/delayed death • 1/3 with acceptable outcome
Surgical considerations • Clipping confers benefit when aneurysm exceeds 10 mm • Initial 72 hr window • Beyond delayed 10-14 days- risk of vasospasm
Anesthetic considerations • Primary concern- prevent rupture • Mortality of rupture on induction exceeds 75% • Likelihood of rupture depends on size, prior rupture, wall strength and transmural pressure • Transmural pressure • CPP= MAP – ICP • Critical periods: induction, dura/arachnoid exposure, hematoma evac, dissection
Induction • Avoid acute increases in blood pressure while preserving CPP • Consider awake A-line, lidocaine, beta blockers, narcotics • Avoid aggressive hyperventilation and hypocapnia
A 45 yo female is experiencing progressive mental deterioration over a 6 hr period, 5 days out from emergent Sah evacuation and aneurysm clipping. Most likely cause is: • A: Cerebral edema • B: Hyponatremia • C: Recurrent cerebral hemorrhage • D: Vasospasm • E: Improper placement of the aneurysm clip
Vasospasm • Subarachnoid bleeders at risk for vasospasm and further ischemia • Rare in day 1-3 • Peaks at day 7 • Resolves around day 10-14 • Symptoms may include: • Change in mentation • New neurologic deficit • Respiratory changes • Diagnosis by angiography and transcranial Doppler
Therapy that is useful in the treatment of cerebral vasospasm includes all of the following except: • A: Blood pressure elevation • B: Hemodilution • C: Diuretics • D: Calcium channel blockers • E: Avoiding hyperglycemia
HHH • HEMODILUTION, HYPERTENSION, HYPERVOLEMIA • Strategy to augment CBF past strictures by CPP and IV volume • Keep MAP normal prior to clipping, High/Normal after clipping • Not indicated for elective aneurysm clipping
Other Considerations • Blood pressure control during pinning and positioning • Surgeon desires cerebral relaxation • Gentle hyperventilation • Osmotic diuretics • Surgeon prefers isoelectric EEG • Bolus and infusion of propofol or etomidate • Increase MAP after deployment • Wake up • Avoid straining, coughing, bucking, and HD liability