Intraoperative wake up procedure with propofol and laryngeal mask for optimal excision of brain tumour in eloquent areas

This is the first thesis describing a new technique for awake craniotomy using a laryngeal mask. Awake craniotomy with propofol infusion has became increasingly popular for the optimal excision of brain tumours located in eloquent areas. During awake craniotomy, tracheal intubation is not performed and propofol infusion is limited to within doses which render the patient just sedated. This asleep-awake procedure is occasionally associated with difficulty in controlling brain volume, especially in patients with a significant mass effect of their brain tumours, since sufficient sedation with propofol tends to cause hypercapnea. We report an intraoperative wake-up procedure employing a laryngeal mask, which enables general anaesthesia to be performed at a sufficient dose of propofol and with control of the brain volume under mechanically assisted ventilation. Before the beginning of cortical mapping, propofol infusion is completely terminated, so allowing the patient to wake up within 5-15 min. Following completion of the tumour excision, general anaesthesia is re-induced at a sufficient dose of propofol. The laryngeal mask can be temporarily removed and repositioned with ease, if necessary. In our experience, this technique is applicable for the optimal excision of brain tumours, especially in patients who are very obese or those who have very large lesions. (C) 2001 Harcourt Publishers Ltd.