General anaesthesia with an awake period for brain surgery

Overview

Objective:
We performed the study to introduce an anaesthetic technique allowing an awake period with intra-operative electrical stimulation of the cortex during craniotomy for resection of tumours affecting the intrinsic cerebral cortex and to confirm the possibility of an awake period during general anesthesia with spontaneous breathing without invasive airway protection in procedures lasting several hours.

Design:
A clinical, prospective study.

Setting:
Department of Anaesthesiology, Resuscitation and Intensive Medicine and Department of Neurosurgery at a University Hospital.

Materials and methods:
The study included 5 patients with a brain tumour affecting the functional cerebral cortex. TIVA (propofol and remifentanil) without invasive airway management was the anaesthetic technique used.

Results:
The average surgical time was 420 min, the average peri-operative emergence period was 73 min. The rates of the anesthetic infusions ranged between 5–8 mg/kg/h of propofol and 1–5 mcg/kg/h of remifentanil. The following complications were observed: 1x considerable discomfort and agitation, 1x epileptic activity and 1x oedema (or expansive behaviour of the lesion).

Conclusion:
General anaesthesia with an awake period allows the use of electrical stimulation of the cortex which – following fMRI and neuronavigation – represents the “golden standard“ of resection of brain tumours affecting functional cortical centers.

Key words:
brain tumour – functional cortex – intravenous anesthesia – awake period – cortical stimulation