Comparison of Dexmedetomidine and Propofol-Remifentanil Conscious Sedation for Awake Craniotomy for Tumor Surgery

Awake craniotomy for resection of brain tumor located in close proximity to areas of eloquent brain function, such as speech, motor and sensory, is an accepted procedure used to minimize neurological injury during resection. During awake craniotomy, anesthesia is usually provided using a combination of local anesthesia (regional scalp block and/or local infiltration) and intravenous (IV) agents to provide sedation, anxiolysis and analgesia. Propofol sedation, commonly in combination with a shorter acting opioid such as fentanyl, or remifentanil, is an effective and popular technique during awake craniotomy, achieving a high degree of patient satisfaction and acceptance. Most of the anesthetic agents are associated with some respiratory depression. The anesthetic agent called dexmedetomidine is a potent, highly selective α2-adrenoceptor agonist. The effects of dexmedetomidine are anxiolysis, analgesia, sedation and sympatholysis, and it is not associated with respiratory depressive effect. Bekker et al. first reported the successful use of dexmedetomidine in awake craniotomy in 2001. The purpose of this blinded, prospective, randomized study is to compare the efficacy of dexmedetomidine versus propofol-remifentanil based sedation in patients undergoing awake craniotomy for resection of tumors. The study hypothesis is that the efficacy of performing intra-operative brain mapping is identical between dexmedetomidine and the propofol-remifentanil based sedation. The primary end-points are to assess the ability to perform intraoperative mapping during awake craniotomy. Secondary end-points will assess the incidence of complications (respiratory depression, failure to provide adequate analgesia), as well as patient and surgeon satisfaction to the corresponding anesthetic technique.