Regional anesthesia improves quality of recovery after surgery in many studies. Ultrasound-guided serratus plane block is a novel technique which may be a viable alternative to current regional anesthetic techniques. This randomized, controlled trial is to examine the effects of ultrasound-guided serratus plane block anesthetic on the QoR after breast tumor resection.

A total of 72 subjects (36 patients for each groups) were enrolled in this study. Patients were allocated to either the general anesthesia group (group control) or SPB (serratus plane block) + general anesthesia groups (group SPB) using randomized central computer-generated sequence software (SAS 19.0). The allocation ratio was 1:1 for the two groups. Group assignment was concealed by opaque sticking envelops. The major research content is to evaluate the quality of recovery using 40 questionnaire (QoR-40).

Inclusion Criteria:

• Patients of American Society of Anesthesiologists' (ASA) Physical Status class I-II scheduled for first modified radical mastectomy were included.

Exclusion Criteria:

• Patients with chronic ethanol
• long-term use of psychotropic drugs (e.g. sedative drugs and antidepressant);
• contraindications for serratus plane block including coagulopathy, infection at the puncture site;
• unable to cooperate with this research due to cognitive impairment, psychopathy or not willing for the hospital follow-up;
• administration of other test drugs or joining in other clinical study in 3 months before our study;
• received radiotherapy or chemotherapy before surgery;
• other conditions not allocated for this study out of the researchers' consideration.