Dexmedetomidine vs propofol-remifentanil conscious sedation for awake craniotomy: a prospective randomized controlled trial

Background: Awake craniotomy (AC) is performed for the resection of brain tumours in close proximity to areas of eloquent brain function to maximize reduction of tumour mass and minimize neurological injury. This study compares the efficacy and safety of dexmedetomidine vs propofol-remifentanil-based conscious sedation, during AC for supratentorial tumour resection. Methods: Prospective, randomized, controlled trial including 50 adult patients undergoing AC who were randomly assigned to a dexmedetomidine (DEX group, n= 25) or propofol-remifentanil group (P-R group, n= 25). The primary outcome was the ability to perform intraoperative brain mapping assessed on a numeric rating scale (NRS). Secondary outcome was the efficacy of sedation measured by the modified Observer's Assessment of Alertness/Sedation (OAA/S) scale. Other outcome measures including haemodynamic and respiratory variables, pain, sedation and anxiety scores, adverse events, and patient satisfaction were also compared. Results: There were no differences between DEX and P-R groups regarding the ability to perform intraoperative brain mapping [mean NRS score (95% CI): 10.0 (9.9-10.0) vs 9.7 (9.5-10.0), P= 0.13] and level of sedation during mapping [mean OAA/S score (95% CI): 4.1 (3.5-4.7) vs 4.3 (3.9-4.7), P= 0.51], respectively. Respiratory adverse events were more frequent in the P-R group (20 vs 0%, P= 0.021). Heart rate was significantly lower in the DEX group across time (P< 0.001); however, the need for treatment of bradycardia was not different between groups. Conclusions: Quality of intraoperative brain mapping and efficacy of sedation with dexmedetomidine were similar to propofol-remifentanil during AC for supratentorial tumour resection. Dexmedetomidine was associated with fewer respiratory adverse events.