Brainstem anesthesia during awake craniotomy: illustrative case

BACKGROUND Awake craniotomy (AC) is performed to remove the lesions near or in eloquent areas, during which the patients are alert and without any airway instrument. Apnea is a severe complication in AC. Here, the authors describe a case of sudden apnea induced by unexpected local anesthesia of the brainstem during AC. OBSERVATIONS A 42-year-old male underwent AC for a large, recurrent, bilateral frontal lobe mass and experienced transient apnea and loss of brainstem reflexes during the surgery. The patient recovered spontaneous breath rhythm just a few minutes after the removal of a lidocaine cotton pledget, which was found near the patient’s midbrain. Then the patient awoke and cooperated to finish the surgery. LESSONS The administration of a local anesthetic subdurally in AC is common but risky. The scouring action of cerebral spinal fluid can spread those agents and cause unexpected brainstem anesthesia. A lower concentration of the anesthetic and keeping away from the cistern can make it safer.