Regional anesthesia and sedation technique with dexmedetomidine for awake craniotomy

M. Lamora, L. Moltó, C. Rodríguez, E. Vilà, J. Fernández-Candil, S. Pacreu
Department of Anaesthesiology. Parc de Salut Mar. Barcelona. Spain

Bakground and aims
Awake craniotomy allows to maximize lesion resection while sparing language, motor and somatosensorial areas of the brain and to minimize the postoperative neurological deficits1. In our hospital, propofol infusion plus remifentanil infusion was the most common option for awake craniotomy. However, patients were sleepy that made it difficult their collaboration during the surgery. Recently, we introduce dexmedetomidine2 (Dex), a selective α2-adrenoceptor agonist with analgesia, sedation and sympatholysis effects and without respiratory depression. We show our experience using regional anaesthesia plus Dex sedation.

Methods
After approval by Ethical Committee, we evaluated during 2015, consecutively five patients underwent awake craniotomy to treat supratentorial tumors. Regional anaesthesia using bupivacaine 0.25% with epinephrine, included the blockade of the cranial nerve V (supraorbital, supratrochlear, zygomathicotemporal and auriculotemporal branches) and the occipital nerves (fig. 1). The scalp, and dura were also infiltrated. Dex infusion was started before infiltrating, stopped before mapping and resumed at the beginning of dura closure. For postoperative analgesia, dexketoprofen, paracetamol and morphine were administered.

Results
One male and four females (ASA II/III) were evaluated. The following results are expressed as median and quartiles: age 32 [27-49] y.o; weight 60 [51-93] kg; length of surgery: 330 [270-360] min. The total bupivacaine was 140 mg. Dex infusion was administered at rate of 0.4 ug/kg/h at the open and closure of craniotomy and stopped during the surgery. No side effects such as nausea, vomiting, local anaesthetic overdose, respiratory depression, hyperalgesia or cardiac instability were observed. One patient presented seizures. There was a low incidence of  intraoperative pain.

Conclusion
Regional anaesthesia and Dex sedation provided adequate conditions for awake craniotomy. It decreases patients’ anxiety, pain medication needs, and level of consciousness without agitation.



References
1- Sarang A, Dinsmore J. Anaesthesia for awake craniotomy. Evolution of a technique that facilitates awake neurological testing. British Journal of Anaesthesia. 2003;90(2):161-5.
2- Bekker AY, Kaufman B, Samir H, Doyle W. The use of dexmedetomidine infusion for awake craniotomy. Anesth Analg. 2001;92:1251-3.