Prospective Comparison of Single-Injection Serratus Anterior Plane Block With Ropivacaine Versus Local Infiltration of Anaesthetic After Breast Surgery

To evaluate whether a serratus anterior plane block (SAPB) is more effective than a local infiltration anesthesia (LIA) with an equal dose and same anesthetic performed by the surgeon, as an adjuvant to treat postoperative pain after unilateral mastectomy. Primary endpoint: the use of opioid's in the postoperative period. Secondary endpoint: Numerical Pain Rating Scale (NPRS) score recorded at the 2nd, 8th, 16th, 24th hour after surgery. 0 means no pain and 10 is the worst pain imaginable. In addition at the same time, we will look to the degree of arm mobilization where there will be 3 possible groups: 1. restricted, 2. fair mobilization and 3. free mobilization. There are 2 treatment arms: 1st arm is the standard therapy, namely the local infiltration anesthesia. 2nd arm is the experimental arm, namely the SAPB. Patients are randomised into each arm after screening.