anesthesia for intracranial aneurysm surgery pekka o. talke, md
TRANSCRIPT
Anesthesia for Intracranial Anesthesia for Intracranial Aneurysm SurgeryAneurysm Surgery
Pekka O. Talke, MDPekka O. Talke, MD
AneurysmsAneurysms
• 2-5 % population2-5 % population
• 30K SAH/yr30K SAH/yr
• 2/3 get to hospital2/3 get to hospital
• 1/3 in hospital severely disabled or dead1/3 in hospital severely disabled or dead
• Unruptured:1-2%/yr ruptureUnruptured:1-2%/yr rupture
• Ruptured: 50% rerupture within 6 moRuptured: 50% rerupture within 6 mo
• Urgent, not emergent casesUrgent, not emergent cases
Anesthetic GoalsAnesthetic Goals
• Prevent aneurysm rupture (avoid hypertension)Prevent aneurysm rupture (avoid hypertension)
• Decrease ICP (surgical exposure, retraction)Decrease ICP (surgical exposure, retraction)
• Maintain CPP (>70 mmHg)Maintain CPP (>70 mmHg)
• Prevent cerebral ischemia from retraction Prevent cerebral ischemia from retraction
• Good operating conditions (NO movement, brain Good operating conditions (NO movement, brain relaxation for exposure)relaxation for exposure)
Patients, preopPatients, preop
• Symptomatic/asymptomaticSymptomatic/asymptomatic
• Ruptured (SAH grade, myocardial effects), Ruptured (SAH grade, myocardial effects), unrupturedunruptured
• Possibly intubatedPossibly intubated
• Location and size of aneurysmLocation and size of aneurysm
• Intracranial mass effect from SAH (increased ICP)Intracranial mass effect from SAH (increased ICP)
• Neurologic deficits and symptomsNeurologic deficits and symptoms
• Timing, vasospasmTiming, vasospasm
PreopPreop
• One IVOne IV
• Premedicate with up to 2 mg of midazolam if Premedicate with up to 2 mg of midazolam if normal mental status.normal mental status.
• Remind of potential post op intubationRemind of potential post op intubation
• Adequate fluid loading (5 to 7 ml/kg of LR, Adequate fluid loading (5 to 7 ml/kg of LR, angio)angio)
InductionInduction
• Routine monitors
• Propofol or thiopental
• Fentanyl 5 ug/kg in divided doses prior to intubation
• Muscle relaxant (roc).
• Arterial cannula before intubationArterial cannula before intubation
• Avoid hypertension (propofol) and hypotension (CPP, vasospasm)
Induction cont.Induction cont.
• Ceftriaxone 1 gm, 4-10 mg decadron, 1 gm/kg mannitol.Ceftriaxone 1 gm, 4-10 mg decadron, 1 gm/kg mannitol.
• Tape eyes with tagaderms (prep solution)Tape eyes with tagaderms (prep solution)
• Temp probe, foleyTemp probe, foley
• Additional IV (limited access, 300 cc to liters of blood loss)Additional IV (limited access, 300 cc to liters of blood loss)
• Compression stockingsCompression stockings
PositioningPositioning
• Supine, bumpSupine, bump
• Long cases, lots of padding (pink and blue Long cases, lots of padding (pink and blue foam)foam)
• Table turned typically 90 degreesTable turned typically 90 degrees
• Head down?, aeroplaningHead down?, aeroplaning• After draping minimal/no access to face After draping minimal/no access to face
(secure ET well)(secure ET well)
MaintenanceMaintenance
• OxygenOxygen
• Propofol infusion (50-200 ug/kg/min) (SSEPs, EEG)Propofol infusion (50-200 ug/kg/min) (SSEPs, EEG)
• Inhalation agent (<0.25 MAC Isoflurane). Muscle Inhalation agent (<0.25 MAC Isoflurane). Muscle relaxation (vec, panc)relaxation (vec, panc)
• Moderate hyperventilation (ET CO2 30 mmHg)Moderate hyperventilation (ET CO2 30 mmHg)
• Euvolemia to 500 cc more (LR)Euvolemia to 500 cc more (LR)
• Moderate hypothermia (34 oC)Moderate hypothermia (34 oC)
Burst supressionBurst supression
• When requested by surgeonWhen requested by surgeon
• Thiopental 125 mg (5 cc) dosesThiopental 125 mg (5 cc) doses
• Till 70-80% EEG burst supressionTill 70-80% EEG burst supression
• Redose as neededRedose as needed
• Turn fentanyl infusion offTurn fentanyl infusion off
• Reduce propofol infusion rateReduce propofol infusion rate
• Support CPP with phenylephrine infusionSupport CPP with phenylephrine infusion
ClippingClipping
• Temporary clips (golden)Temporary clips (golden)
• Permanent clips (silver)Permanent clips (silver)
• Aneurysm manipulation before clipping (bleed)Aneurysm manipulation before clipping (bleed)
• Record clip on/off timesRecord clip on/off times
• Maintain CPP during temporary clippingMaintain CPP during temporary clipping
• Start closing, warming and more fluid loading after Start closing, warming and more fluid loading after clippingclipping
Toward the endToward the end
• First indication of end of surgery when clip First indication of end of surgery when clip aneurysm (60 min)aneurysm (60 min)
• Normalize CO2 once dura closed or earlier if Normalize CO2 once dura closed or earlier if lots of intracranial spacelots of intracranial space
• Reduce propofol if possible, and titrate in Reduce propofol if possible, and titrate in labetalollabetalol
Toward the end Toward the end cont.cont.
• Turn propofol infusion off about 10 min Turn propofol infusion off about 10 min before wakeupbefore wakeup
• Reverse relaxation once Mayfied pins have Reverse relaxation once Mayfied pins have been removedbeen removed
• Attempt to wakeup patient. Unlikely if more Attempt to wakeup patient. Unlikely if more than 1 gm of thiopental given.than 1 gm of thiopental given.
RecoveryRecovery
• Wake patient up as soon as possibleWake patient up as soon as possible
• Extubate if possibleExtubate if possible
• Prevent post op hypertension (bleed). Prevent post op hypertension (bleed). LabetalolLabetalol
• Transport to ICU with monitor and oxygenTransport to ICU with monitor and oxygen
• Head up positionHead up position
Potential ComplicationsPotential Complications
• Delayed awakening from anesthesiaDelayed awakening from anesthesia
• Cerebral ischemia (retraction, temporary Cerebral ischemia (retraction, temporary clips, vasospasm)clips, vasospasm)
• Brain swellingBrain swelling
• Intraoperative hemorrhageIntraoperative hemorrhage
Aneurysm ruptureAneurysm rupture
• Reasonably commonReasonably common
• Intubation, pinning, skin insicion, surgical Intubation, pinning, skin insicion, surgical manipulationmanipulation
• Maintain intravascular volume (blood in the room, Maintain intravascular volume (blood in the room, get help)get help)
• Maintain CPPMaintain CPP
• Adequate anesthesiaAdequate anesthesia
• Thiopental before temporary clippingThiopental before temporary clipping
VasospasmVasospasm
• Only if SAHOnly if SAH
• 5-14 days after SAH5-14 days after SAH
• Leading cause of SAH morbidity (infarct)Leading cause of SAH morbidity (infarct)
• Maintain CPP at all times (neo infusion, Maintain CPP at all times (neo infusion, volume)volume)
• HHH therapyHHH therapy
• Consider CVP measurementConsider CVP measurement
What’s new?What’s new?
• Retractor pressure Retractor pressure
• Temp controlTemp control
• NormotensionNormotension
Surgical StepsSurgical Steps
• Mayfield pins (stimulation), head positioningMayfield pins (stimulation), head positioning
• Shaving/prepping/local anesthesiaShaving/prepping/local anesthesia
• Skin incision (stimulation, blood loss)Skin incision (stimulation, blood loss)
• Scalp off the bone (most stimulation)Scalp off the bone (most stimulation)
• Burr holes, sawingBurr holes, sawing
• Removing boneRemoving bone
• Open duraOpen dura
• Surgical approach to aneurysm (microscope, Surgical approach to aneurysm (microscope, minimal stimulation, retraction)minimal stimulation, retraction)
Surgical Steps cont.Surgical Steps cont.
• Burst supressionBurst supression
• Temporary clips, permanent clip(s)Temporary clips, permanent clip(s)
• Close (60 min)Close (60 min)
• Dura (water tight)Dura (water tight)
• Bone flapBone flap
• Scalp and skinScalp and skin
• Dressing, remove pinsDressing, remove pins