Safety and Analgesic Efficacy of a Modified Auriculotemporal Nerve Block

Safety and Analgesic Efficacy of a Modified Auriculotemporal Nerve Block: a Prospective, Randomized, Double-blind, Traditional Controlled Study

1. Efficacy of a modified auriculotemporal nerve blockade for patients undergoing supratentorial craniotomy
2. Safety of a modified auriculotemporal nerve blockade for patients undergoing supratentorial craniotomy

Scalp nerve block for supratentorial craniotomy patients can effectively reduce the consumption of perioperative analgesic drugs, avoid the occurrence of hypertension and tachycardia, relieve postoperative pain, improve postoperative recovery quality of patients. Scalp nerve block is safe and has fewer complications due to the small amount of local anesthetic. For auriculotemporal nerve block, temporary block of adjacent facial nerve is one of the most likely complications, with an incidence of 8.6%, and usually can be recovered within 24 hours, since the facial nerve was located in the anterior and lower part of the tragus, 1 cm deep in the skin. Therefore, improving nerve block methods and reducing the dosage of local anesthetics may reduce the risk of facial nerve block. The investigators proposed helix feet in front of the zygomatic arch as anatomy marks of auriculotemporal nerve block, and the modified auriculotemporal nerve blockade is implemented as follows: Zygomatic arch level, posterior to the superficial temporal artery, the vertical puncture depth is about 0.5 -1 cm, and 2 ml of local anesthetics are injected after withdrawing without blood. The study intends to compare a modified auriculotemporal nerve block method with the traditional way, reflecting on perioperative hemodynamical fluctuation, postoperative analgesia effect and incidence of facial nerve paralysis. This will verify the safety and analgesic efficacy of the modified nerve block method proposed in this study, and then provide a basis for improving the quality of perioperative management during neurosurgery.

Inclusion Criteria:

1. Patients undergoing supratentorial craniotomy under general anesthesia;
2. 18-65 years old;
3. ASA I or II.

Exclusion Criteria:

1. Emergency surgery;
2. Be allergic to ropivacaine;
3. Participating in other clinical investigation within 30 days;
4. Skin infection at the puncture site;
5. Patients taking analgesic drugs before surgery;
6. Persons addicted to alcohol or drugs;
7. Patients with severe liver and kidney dysfunction;
8. Patients with coagulation disorder;
9. Pregnant and lactating women;
10. Patients with consciousness disorder before surgery;
11. Those who have undergone neurosurgery within the last 6 months;
12. Patients who were unable to understand the NRS before surgery.