Background: Craniotomy causes acute and chronic pain. Uncontrolled postoperative pain may lead to adverse events. Perioperative scalp nerves block is not only effective in reducing intraoperative hemodynamic response, but it also reduces postoperative pain and postoperative analgesia requirement.

Objective: To compare the benefits of adding dexmedetomidine to levobupivacaine in scalp nerves block before craniotomy for the duration of analgesia in supratentorial craniotomy.

Materials and Methods: After approval by the Committee for Research, 50 supratentorial craniotomy patients were randomized into two groups. The control group received 30 mL scalp nerves block with 0.25% levobupivacaine with adrenaline 1:200,000, whereas the study group received 30 mL scalp nerves block with 0.25% levobupivacaine with adrenaline 1:200,000 plus dexmedetomidine 1 mcg/kg. The primary outcome was the time to first analgesic requirement postoperatively. The secondary outcomes included intraoperative fentanyl consumption, verbal numerical rating scale, tramadol consumption, and complications during the first 24 hours postoperatively.

Results: Patients in the study group had significantly increase time to the first analgesic requirement in postoperative period and reduced intraoperative fentanyl consumption. The median time to first analgesic requirement was 555 (360 to 1,035) minutes in the study group versus 405 (300 to 520) minutes in the control group (p=0.023). Intraoperative fentanyl consumption 125 (75 to 175) mcg in the study group was significantly lower than 200 (150 to 250) mcg in the control group (p=0.02). The verbal numerical rating scale at 1, 4, 8, 12 and 24 hours postoperatively, tramadol consumption, and complications during the first 24 hours postoperatively were not statistically significant different.

Conclusion: Preoperative scalp nerves block with 0.25% levobupivacaine with adrenaline (1:200,000) with dexmedetomidine 1 mcg/kg significantly increased the time to first analgesic requirement and reduced intraoperative fentanyl consumption compared to 0.25% levobupivacaine with adrenaline (1:200,000) without perioperative complications.

Keywords: Scalp block, Dexmedetomidine, Post-craniotomy analgesia, Supratentorial tumor, Levobupivacaine

DOI: doi.org/10.35755/jmedassocthai.2020.10.11547

Received 8 June 2020 | Revised 7 August 2020 | Accepted 10 August 2020