Page 11 - CASA Bulletin of Anesthesiologisy 2022 9(6)-1 (3)

Vol. 9, No 6, 2022

the patient regarding the discomfort encountered during surgery, seek the opportunity for coping
method (e.g., preferred music), address their concerns and provide reassurances. Since an
anesthesiologist is in hearing range and visible to the patient at all times during the procedure,
patients often rely on the anesthesiologist at times of stress during surgery. A good patient-
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anesthesiologist rapport is, therefore, crucial to the success of awake craniotomy . In addition,
participation of the neuropsychologist responsible for intraoperative testing is very important
even at this stage of care . Comprehensive multicomponent psychological preparation and the
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establishment of a trusting relationship between the patient and surgical team in most cases allow
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us to avoid or minimize the use of sedative premedication .
Preoperative anxiolytics for patients with significant anxiety should be added judiciously.
Benzodiazepines (esp. midazolam) are common choices. The addition of these medications
should be balanced against the risk of altered mental status or failure to arouse for intraoperative
testing, and respiratory insufficiency leading to hypercapnia and raised ICP. Some centers report
using no sedation at all, some centers start the loading infusion of dexmedetomidine upon entry
to the operating room . Oral Tylenol may be taken preoperatively to alleviate intraoperative
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headache.

Intraoperative anesthetic management

Goals

The essential goals of anesthetic management for a successful awake craniotomy include
’ e procedure, ensuring adequate brain
relaxation and hemodynamic stability, and ensuring a rapid and smooth emergence for
intraoperative speech, memory or motor testing.

Common anesthetic approaches

Two dominant anesthetic approaches, conscious sedation (CS) and asleep–awake–asleep
(AAA), are widely used in awake craniotomy with no evidence that one technique is superior to
the other . With CS approach, patients are sedated but readily arousable and able to maintain
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spontaneous breathing before and after neurological testing. With AAA approach, patients are
unconscious under GA with or without mechanical ventilation (LMA or ETT) before and after
neurological testing. The advantages of CS approach include stable hemodynamics, less delirium
and agitation upon emergence for testing, less coughing due to absence of a LMA or ETT.
However, there are risks of pain and anxiety, sudden movement, airway obstruction, elevated
ICP due to respiratory insufficiency with CS approach. The advantages of AAA approach with
intubation (LMA or ETT) include better patient comfort, no patient movement, controlled
airway, ability to hyperventilate and less brain swelling. However, there are risks of
hemodynamic fluctuations, delirium and agitation upon emergence for testing, shivering,
coughing and scalp laceration from head pins upon extubation, drowsiness from residual
anesthetics, and nausea and vomiting. The AAA approach without airway intubation (e.g., nasal
cannula, oxygen mask) carries higher risks of airway obstruction and elevated ICP than CS
approach due to higher level of sedation.

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