Before surgery, an ultrasound-guided ESPB was performed. 30 mL of 0.375% ropivacaine and 0.5μ g/kg dexmedetomidine mixture was injected in the interfascial plane between rhomboideus major and erector spinae muscle.

Ropivacaine is produced by AstraZeneca AB under the trade name of Naropin, and the specifications are 75 mg / 10 ml. Dexmedetomidine is produced by HengRui medical China and the specifications are 100μg / 1 ml。

Control groups do not receive additional analgesia.

In the ESPB group, the patients were placed in the lateral decubitus position. The ultrasound probe was located in longitudinal orientation at the level of the T4 spinous process and then placed 3 cm laterally from the midline to the side involved in the surgery. The ultrasound landmarks, T4 transverse process, and the overlying trapezius, rhomboideus, and erector spinae muscles, were identified. Under aseptic conditions, an 80-mm 21-gauge block needle was inserted in-plane at an angle of 30-40° in the cranial-to-caudal direction until the tip contacted the T4 transverse process.After the hydrodissection with 2-3 mL of isotonic saline solution confirmed the correct needle tip position, the intermixture was injected in the interfascial plane between rhomboideus major and erector spinae muscle. Local anesthetic spread in a fascial longitudinal pattern deep to the erector spinae muscle was visualized using ultrasound guidance.

11-point numerical rating scale(0=no pain, 10=worst pain) at 6th hour following the surgery

The QoR-15 will be used to evaluate postoperative quality of recovery from 15 dimensions. The QoR-15 scale is a global measurement of postoperative recovery, consisting of 15 items with 10 points each, with a total score ranging from 0 (QoR very poor) to 150 (QoR very good).

Number of patients who experienced nausea and vomiting after surgery.

Including mean blood pressure(mmHg), heart rate(beats/min) during the surgery.