anesthesia for intracranial aneurysms l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Anesthesia For Intracranial Aneurysms PowerPoint Presentation
Download Presentation
Anesthesia For Intracranial Aneurysms

Loading in 2 Seconds...

play fullscreen
1 / 37

Anesthesia For Intracranial Aneurysms - PowerPoint PPT Presentation


  • 394 Views
  • Uploaded on

Anesthesia For Intracranial Aneurysms. Objectives. Understand the incidence and pathophysiology of aneurysms Considerations in management of aneurysms Anesthetic management New considerations in management of intracranial aneurysms. Incidence. 75% of subarachnoid hemorrhages

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Anesthesia For Intracranial Aneurysms' - Lucy


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
objectives
Objectives
  • Understand the incidence and pathophysiology of aneurysms
  • Considerations in management of aneurysms
  • Anesthetic management
  • New considerations in management of intracranial aneurysms
incidence
Incidence
  • 75% of subarachnoid hemorrhages
  • 27,000 American/year
  • 6-49 per 100,00 year depending on location
  • Female predominance
  • Age 40-60
incidence4
Incidence
  • Ruptured intracranial aneurysm (IA)
    • 20% morbidity
    • 20% mortality
  • Unruptured IA
    • 4% morbidity
    • 0-2% mortality
pathophysiology
Pathophysiology
  • Arterial wall abnormalities
  • Saccular, occur at bifurcations
  • Disease processes associated with an increased risk of IA
    • Polycystic kidney
    • Erloh Danlos
    • Fibromuscular disease
    • Coarctation of the aorta
classification
Classification
  • Small – less than 12 mm
  • Large – 12-24 mm
  • Giant - 24mm
ia rupture
IA Rupture
  • Increase ICP
  • ICP greater than DBP
  • Bleeding stops with decreased CBF
  • Decreased consciousness
  • 2 clinical scenarios typical
    • 1. Return to normal ICP and CBF with return of function
    • 2. High ICP continues with low CBF
factors associated with an increased risk of rupture
Factors associated with an increased risk of rupture
  • Hypertension
  • Pregnancy
  • Smoking
  • Heavy drinking
  • Strenuous activity
ia grading
IA Grading
  • GradeCriteriaPerioperative Mortalit
  • 0 Aneurysm is not ruptured 0-5
  • I Asymptomatic, min. headache and sl. nuchal rigidity 0-5
  • II Moderate to severe headache, nuchal rigidity, but no neurologic deficit other than cranial nerve palsy 2-10
  • III Somnolence, confusion, medium focal deficits 10-15
  • IV Stupor, hemiparesis medium or severe, possible early decerebrate rigidity, vegetative disturbances 60-70
  • V Deep coma, decerebrate rigidity, moribund appearance 70-100
world federation of neurologic surgeons wfns sah grade
World Federation of Neurologic Surgeons (WFNS) SAH grade
  • WFNS grade GCS Score Major focal deficit*
  • (0 intact aneurysm) - -
  • 1 15 absent
  • 2 13-14 absent
  • 3 13-14 present
  • 4 7-12 present or absent
  • 5 3-6 present or absent
vasospasm
Vasospasm
  • High incidence angiografically
  • Clinical symptoms
  • 4 – 11 days post bleed
vasospasm13
Vasospasm
  • Free hemoglobin - activates cascade
  • Histamine, serotonin, catecholamines, prostaglandins, angiotensin, and free radicals
  • Blood vessel walls abnormal
vasospasm14
Vasospasm
  • Treatment
    • Triple H therapy
    • Calcium channel blocker - nimodipine
    • Early surgery with aggressive removal of blood
rebleed
Rebleed
  • 14-30 %
  • Peak incidence first few days post bleed and second week post bleed
  • High risk of rebleed during angiography
cardiovascular effects
Cardiovascular effects
  • ECG abnormalities
    • Very common
    • Many changes seen
      • cannon t wave, Q-T prolongation, ST changes
    • Autonomic surge may in fact cause some subendocardial injury from increase myocardial wall tension
cardiovascular effects18
Cardiovascular effects
  • Cardiac dysfunction does not appear to affect morbidity or mortality (studies from Zaroff and Browers)
  • Prolonged Q-T with increased incidence of ventricular arrhythmias
  • PVC’s are seen in 80%
slide19
QTdc
  • Difference between the longest and shortest QT interval on a 12 lead
  • Increase reported to be associated with cardiorespiratory compromise and need for inotropes (Br. J Anesth. 82:454p-455p, 1999)
neurologic effects
Neurologic effects
  • Hydrocephalous
  • Seizures
    • 13%
    • Vasospasm may be cause
    • Increased risk of rebleed
    • Treat and prophylaxis
  • Headache, visual field changes, motor deficits
endocrine effects
Endocrine Effects
  • SIADH
  • Cerebral salt wasting syndrome
    • release of naturetic peptide
    • hypovolemia, increased urine NA and volume contraction
  • Distinguish between the two and treat accordingly
pulmonary effects
Pulmonary Effects
  • Neurogenic pulmonary edema
  • 1-2% with SAH
  • Hyperactivity of the sympathetic nervous system
  • Pneumonia in 7-12% of hospitalized patients with SAH
timing of surgery
Timing of surgery
  • 0-3 days post bleed appears to be optimal
  • Improved outcome within 6 hours of rupture despite high H/H grade
  • If delayed, 2 weeks post bleed after fibrinolytic phase
anesthetic goals
Anesthetic Goals
  • Avoid abrupt changes in BP
  • Maintain CBF with normal to high blood pressure
  • Be prepared for disaster
monitors
Monitors
  • Arterial line preinduction
  • CVP as indicated
    • Triple H therapy may be used post op
  • Neurologic monitoring
    • SSEPs and BAERs useful for posterior circulation aneurysm
induction
Induction
  • REBLEEDING IS LETHAL!!!
  • Careful blood pressure control
  • Weigh risk of full stomach vs. adequate depth of anesthesia and relaxation
  • Titrate induction agent
  • Blunt response to intubation
induction27
Induction
  • Thiopental 3-6mg/kg reduces CBF and O2 consumption but does not blunt hemodynamic response. Need supplemental agents
  • Propofol and etomidate good alternates
  • Succinylcholine controversy ….
  • Beta blockers and vasodilators on hand
maintenance
Maintenance
  • Goals
    • Cerebral relaxation and protection
    • Hemodynamic stability
    • Normovolemai to hypervolemia
    • Control ICP
    • … and wake up on a dime
maintenance29
Maintenance
  • Agents
    • Inhalational agents, narcotics, oxygen,
    • N2O controversial
      • Can increase CBF
  • Glucose management
  • Hyperventilation
fluids
Fluids
  • Isotonic or hypertonic solutions
  • Mannitol
    • Increase intravascular volume
    • Effect in 5-15 min. with peak at 30-45
    • Careful administration in those with reduced cardiac function
hypothermia
Hypothermia
  • Moderate hypothermia determined to be protective in some animal studies (33-35 degrees)
  • Mild hypothermia (35.5) found to improve outcome but not statistically significant
  • Deep hypothermic arrest for giant aneurysms
intraoperative hemorrhage
Intraoperative hemorrhage
  • Hypotension to control
  • 40 -50 mmHG
  • Temporary clips
  • Pressure on ipsilateral carotid for anterior circulation
emergence
Emergence
  • Anticipate stimulating events
  • Keep beta blockers and vasodilators on hand
extubation
Extubation
  • Decision to extubate made by anesthesia provider and surgeon
  • Higher grade bleeds may need to go to ICU intubated
new management
New management
  • Endovascular balloon placement
  • Tirilazad
    • Antioxidant
    • Appears to decrease need for HHH therapy in men
    • No improved outcome
new management36
New Management
  • Vasospasm
    • Intraventricular SNP used in severe refractory cases, however effects are highly variable