"Awake" Craniotomy Guidelines
T. Rintel April 2009
A. Two neurosurgeons, Drs. Florman and Desai, are performing "awake" craniotomies on select patients. The increased number of "awake" cases is based on new data that suggests that there is a near linear relationship between tumor mass excision and survival. In the past, were a mass in an "inaccessible" area (motor, speech, etc.), the patient was biopsied only, leaving the mass to non-surgical therapy. Now with the advent of "awake" surgery; one can resect a much greater tumor mass.
It is worthwhile for the anesthesia care team to take the time to establish rapport with the patient. The patient will naturally have some level of apprehension and will need reassurance. Confused, agitated, or demented patients are very poor candidates for this procedure.
Dr. Florman has performed the majority of awake cranis at Maine Medical Center. His preferred technique is:
-Mild sedation in the ASU, versed and ± fentanyl
- Propofol bolus for pin placement
- Propofol infusion (spontaneous ventilation) for the craniotomy – through the dura then turn off!
- Having checked with the surgeon, small amounts of versed and/or fentanyl may be given intermittently
- Restart the propofol infusion for closure.
- Standard monitors, ETCO2, BP cuff, EKG, mask or nasal prong O2
For Dr. Desai a similar technique will work, though he is not averse to using remifentanil. [search ‘remifentanil' on this website for mixing and dosing remifentanil, and Dr. J. Flowerdew's article on anesthesia for scoliosis with intra-op wakeup]
II. Common problems (see Handbook of Neuroanesthesia for comprehensive review)
- Airway complications
- Seizures (may occur during cortical stimulation and can be treated with versed)
- Less commonly; disinhibition, cortical swelling, n/v
As a rule, communication between the surgeon and the anesthesia care team is critical and a brief pre-op discussion can be very helpful