Anaesthesia for awake craniotomy

Abstract

insensitive action of C-fibre input in the rat spinal cord. Neurosci Lett 1986; 64: 221-5 Anaesthesia for awake craniotomyTo the Editor: Assessment of consciousness and motor function is important in many neurosurgical procedures. We report a case where general anaesthesia without tracheal intubation was induced for craniotomy, the patient was awakened, minimal changes in speech and vision were ascertained, and the patient was then re-anaesthetized for skull closure. This patient is a 28-yr-old 60 kg woman referred for resection ependymoma of the motor and speech cortex. Cortical mapping was planned to identify areas at risk and to preserve as much normal tissue as possible, requiting the patient to be awake and alert with discriminatory functions intact.At the preoperative, the patient understood the value of being awake for cerebral protection but was hesitant to being conscious for the opening of her skull, but she agreed to the following procedure. After ascertaining a therapeutic dilantin level (22.6 rag. ml-I), she received midazolam 1.5 mg/v. Anaesthesia was induced with sufentanil, 20 ~g and propofol 100 mg bolus, after lidocaine 25 mg. The lungs were easily vendated by mask. An 8.0 mm nasal airway was shortened to 22 cm, placed in the right naris, and connected to the breathing circuit by a #7 endotracheal tube connector. With this arrangement, we were able to ventilate the lungs by closing the mouth and applying 20 mmHg to the bag. After spontaneous respiration resumed, a propofol infusion was titrated at 7 mg. kg -~. hr -l and supplemented with 60% N20 / 02. Bupivacaine was injected in the skull prior to tongs placement and skin incision. Ability to ventilate was checked again after she was placed in Mayfield tongs with her head in the semi-lateral position. Spontaneous respiration was maintained with SpO2 of 100% and PEXCO 2 <55 mmHg.The case proceeded without incident for four hours. At the surgeon's request, the propofol infusion and nitrous oxide were discontinued. The patient awoke seven minutes later and answered questions appropriately. She identified areas of cortical stimulation, changes in conjugate eye motion, and was aware of mild degrees of dysarthria which resolved with the cessation of stimuli. Very small incremental doses of sufentanil 20 ~tg and midazolam 1.0 mg were used to increase her comfort during the four hours that she remained awake.The only unexpected event was a three-minute episode of non-thermogenic shivering upon awakening which resolved without treatment. Focal seizures occurred several times with cortical stimulation and resolved with discontinuation of the stimulation. Following tumour removal, she was re-anaesthetized at her request for skull closure using propofol, N20, 02, and sufentanil. The total duration of the case was 11 hr.We were pleased with the ease of providing an effective anaesthetic for a difficult problem. Potential difficulties considered included vomiting, grand mal seizures, or a psychotic episode. Fortunately, this young woman did well and was dis...

Anesthetic Complications of Awake Craniotomies for Epilepsy Surgery

“…Only 3 of 332 AAA patients required airway control with an endotracheal tube or LMA, including one patient in whom remifentanil was used in addition to propofol (a departure from our usual protocol). Two other patients experiencing desaturations simply had nasal airway devices placed and connected to the anesthesia circuit with adequate oxygen saturations (previously described as a means of improving oxygenation with spontaneous breathing and with controlled ventilation by closing the mouth and applying pressure to the reservoir bag) (23). Obesity (body mass index Ͼ30 kg/m 2 ) appeared to be a consistent risk factor that led to oxygen desaturations requiring a secure airway.…”

Initial Experience with Awake Craniotomy In Sudan

“…However, the technique has got similar disadvantages to that of endotracheal intubation. Alternatively awake craniotomy has been conducted without airway support and with oxygen supplementation through a nasal canula 2, 3, 6-8. This technique, although comfortable, carries the risk of depression of ventilatory drive 2,3,[6][7][8] , transient desaturation and hypercapnia 6-8. Weiss 9 placed a nasopharyngeal airway, which was then connected to a breathing circuit via a tracheal tube connector: thus enabling patent airway and assisted ventilation. As shown from this case, reported above, the indication for awake craniotomy was influenced by the patient's critical cardiovascular condition, which seems to be an abnormal indication.…”

Awake craniotomy: A qualitative review and future challenges

“…In 1993, Weiss placed a tracheal tube in one nostril at 22 cm in order to support ventilation during propofol administration with N 2 O general anesthesia. [ 49 ]…”