Transcript Current Controversies in the Perioperative Management of

Anesthesia for Supratentorial
Tumors
Pekka O. Talke, MD
Department of Anesthesia and
Neurosurgery, Cottrell
Chief of Neuroanesthesia
University of California, San Francisco
Title
•
•
•
•
35.000 brain tumors/yr
85% primary
60% primary and supratentorial
15% mets (1/6 of tumors)
General Considerations
•
•
•
•
•
•
Surgical exposure (retraction)
Intracranial pressure (ICP)
Secondary insult to brain
Hemorrhage, seizures, air emboli
Rapid emergence
Stress response
ICP
•
•
•
•
Tissue, blood, CSF
Intracranial-Volume relationship
Effects of anesthetics on ICP
Tumor mass and edema (steroids)
Anesthetics
• Intravenous anesthetics (not ketamine) are
cerebral vasoconstrictors
• Reduce CMR
• CO2 reactivity intact
Anesthetics cont.
• Volatile anesthetics are cerebral
vasodilators
• Increase ICP
• Reduce CMR
• CO2 reactivity intact
Anesthetics cont.
•
•
•
•
•
Nitrous oxide increases CMR and ICP
Can be controlled by hypocapnia
Opioids reduce CMR
CO2 reactivity intact
Nitroglycerine, nitroprusside, hydralazine
are cerebral vasodilators
Reduction of ICP
• Intravenous anesthetics
• Hyperventilation (30-35 mmHg)
• Mannitol (0.5-1.0 gm/kg, 320 mOsm/kg),
•
•
•
•
•
(hypernatremia, hypokalemia, hypovolemia)
hypertonic saline
Lasix
CSF drainage
Hypoxia, hypovolemia
Head position (venous drainage)
Increase MAP
Preop Plan
•
•
•
•
•
•
Vascular access
Fluid therapy
Anesthetics
Ventilation
Monitoring
Neuromonitoring
Preop
• Sedation=hypercapnia, hypoxia, obstruction
• Stress: increased CMR, CBF
• Analgesia/sedation midas 0.5.-2.0
mg/fentanyl (25- 100 ug)
• Steroids
• Anticonvulsants (relaxants, loading SLOW)
Preop cont.
• Two large Ivs
• A-line (CPP, ABG, glucose, osm)
• Asleep? To avoid stress
Monitoring
•
•
•
•
•
•
•
BP, HR, CVP?
Pulse ox
ERTCo2
Temperature (hypothermia?)
Urine
Relaxometry (hemiplegia, dilantin, tegretol)
Glucose, Hg, Hct
Monitoring cont.
•
•
•
•
EEG
SSEP
ICP?
Motor mapping
Induction
•
•
•
•
•
Avoid hypoxia, hypercarbia, stress response
Propofol/pentothal/hyperventilate
Opioids/relaxants
Head position (venous obstruction)
More drugs for intubation/pinning
Maintenance
• Control CMR, CBF
• Good depth of anesthesia
• Adequate CPP
Maintenance cont.
• Volatile (<1 MAC)/intravenous
anesthetics/N2O
• Mild hyperventilation
• Aim for speedy emergence (CT scan)
Increased ICP
•
•
•
•
•
•
Hyperventilate
Venous drainage
Relaxation
Change to IV anesthesia
Delete N2O
Diuretics
Fluids
• Not hypoosmolar
• Colloids (bleeding)
• Mannitol (320 mOsm/g)
Emergence
• Attenuate stress response (autoregulation
•
•
•
•
impaired/labetalol)
Avoid hypercarbia, hypoxia (opioids)
Avoid coughing
Slow awakening (CT)
Seizure, edema, hematoma,
pheumocephalus, vessel occlusion,
ischemia, metabolic
Title
Title
Title
Intracranial
• Increased intracranial pressure
• Midline shift: tearing of the cerebral vessels
• Herniation: falx, transtentorial, transforamen
• Magnum, transcraniotomy
• Epilepsy
• Vasospasm
Systemic
•
•
•
•
•
•
•
•
Hypercapnia
Hypoxemia
Hypotension or hypertension
Hypoosmolality or hyperosmolality
Hypoglycemia
Hyperglycemia
Shivering or pyrexia
Low cardiac output
Prevention
• No overhydration
• Sedation, analgesia, anxiolysis
• No noxious stimulus applied without sedation
and Local Anesthesia
• Head-up position, no compression of the jugular
veins, head straight
• Osmotic agents: mannitol, hypertonic saline
Prevention cont.
•
•
•
•
•
•
•
Beta-blockers or clonidine or lidocaine
Steroids, if a tumor is present
Adequate hemodynamics: MAP, CVP, PCWP, HR
Adequate ventilation: Paco2>100 mm Hg, Paco2 35 mm Hg
Intrathoracic pressure as low as possible
Hyperventilation on demand before induction
Use of intravenous anesthetic agents for induction and
maintenance in case of tensed brain
Treatment
•
•
•
•
CSF drainage if ventricular or lumbar catheter in situ
Osmotic agents
Hyperventilation
Augmentation of anesthesia with intravenous anesthetic
agents: propofol, thiopentone, etomidate
• Muscle relaxant
• Venous drainage: head up no PEEP, reduction of
inspiratory time
• Mild controlled hypertension if autoregulation present
History
• Seizure
• Increased intracranial pressure (ICP): headache,
nausea, vomiting, blurred vision
• Decreased level of consciousness, somnolence
• Focal neurologic signs: hemiparesis, sensory
deficits, cranial nerve deficits, and so on
• Paraneoplastic syndromes including presence of
thrombosis
Physical Evaluation
• Mental status
• Papilledema (increased ICP)
• Signs of Cushing’s response: hypertensive
•
•
•
•
bradycardia
Pupil size, speech deficit, Glasgow coma score,
focal signs
Medication
Steroids
Antiepileptic drugs
Technical Examination (CT or MRI Scan)
• Size and location of the tumor: silent or eloquent
area, near a major vessel, and so on
• Intracranial mass effect: midline shift, decreased
size of the ventricles, temporal lobe hernia
• Intracranial mass effect: hydrocephalus,
cerebrospinal fluid space around brainstem
• Others: edema, brainstem involvement,
pneumocephalus (recraniotomy)
Evaluation of Hydration Status
•
•
•
•
Duration of bed rest
Fluid intake
Diuretics
Inappropriate secretion of antidiuretic
hormone
Induction
• Adequate anxiolysis in the anesthetic room
• Adequate fluid loading (5 to 7 ml/kg of NaCl 0.9%)
• ECG leads in place; capnometer, pulse oximeter,
and noninvasive blood pressure monitors
• Insertion of intravenous and arterial lines under
local anesthesia
• Fentanyl 1 to 2 g/kg or alfentanil, sufentanil, or
remifentanil
Induction cont.
• Preoxygenation and voluntary hyperventilation
• Propofol 1.25 to 2.5 mg/kg or thiopentone 3 to 6 mg/kg
for induction
• Nondepolarizing muscle relaxant: vecuronium,
rocuronium, or other controlled ventilation at Paco2 of
35 mm Hg
• Propofol 50 to 150 g /kg/min or isoflurance 0.5% to
1.5% (or sevoflurane of desflurane) for maintenance
and fentanyl (or alfentanil, sufentanil, or remifentanil) 1
to 2 g/kg or alfentanil, sufentanil, or remifentanil
Induction cont.
• Lignocaine 1.5 mg/kg
• Intubation
• Local anesthesia and intravenous fentanyl 2 g/kg for
•
•
•
•
skull-pin head-holder placement and skin incision
adequate head-up positioning; no compression of the
jugular veins
Mannitol 0.5 to 0.75 g/kg
Insertion of a lumbar drain
Possibly N2O when the dura is open and brain is slack
Normovolemia with the use of NaCl 0.9% or starch 6%—no
Ringer’s lactate
ICP Control
• Mild hyperosmolality (use NaCl 0.9% [304
mOsm/kg]
as baseline infusion; give mannitol [1319
mOsm/kg]
0.5 to 0.75 g/kg or hypertonic saline [7.5% 2533
mOsm/kg] 3 to 5 ml/kg before bone flap removal)
• Intravenous anesthetic agent (propofol), adequate
depth of anesthesia
• Mild hyperventilation, mild hyperoxygenation
ICP Control cont.
• Mild controlled hypertension: MAP maintained around 100
mm Hg in order to decrease CBV and ICP
• Normovolemia; no vasodilators
• Mild hyperoxia
• Together with:
– Adequate head-up positioning
– Free venous drainage; no compression of the jugular veins
– No PEEP, no ventilator fight (myorelaxants)
– Lumbar drainage
– Avoidance of brain retractors
Awakening
• Neurosurgical awakening should maintain:
–Stable arterial blood pressure and thus
cerebral blood flow and intracranial pressure
–Stable oxygenation and carbon dioxide
tension
–Stable CMRO2
–Normothermia
Awakening cont.
• Neurosurgical awakening should avoid:
–Coughing
–Tracheal suctioning
–Airway overpressure during extubation
–Patient-ventilator dyssynchrony
Awakening cont.
• Neurosurgical awakening should provide:
–Optimal conditions for neurologic examination