Analgesic Effect to Postoperative Pain After Mastectomy: Ultrasound-guided Serratus Anterior Plane Block

Ultrasound guided serratus anterior plane block may decrease acute postoperative pain and consumption of opioid after mastectomy.

Inclusion Criteria:

1. ASA 1~3
2. Age 20~80
3. Breast cancer patient twho are scheduled for elective mastectomy

Exclusion Criteria:

1. Allergy to local anesthetics or contraindication to use of ropivacaine
2. Pregnancy
3. Severe cardiovascular disease
4. Renal failure
5. Liver failure
6. Neurologic and psychologic disease
7. Chronic treatment with analgesics
8. Previous history of mastectomy or thoracic surgery.