no participants recruited due to logistic problems

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.

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.

Inclusion Criteria:

• Age 18-80 years.
• Provision of signed informed consent prior to any study-specific procedure.
• Patients who come to preoperative anesthesia consultation for their scheduled unilat-eral mastectomy.

Exclusion Criteria:

• Age >80 years
• History of chronic pain or drug treatment abuse
• Depression, psychiatric morbidity or mal-adaptive coping behavior
• Neuropathy
• Severe anxiety or other mental ailment, taking drugs affecting their capacity to assess pain
• Chronic or acute skin infection of the lateral thorax
• Hypersensitivity to ropivacaine
• Severe hepatic or renal disease
• Refuse to participate to the study
• Pregnancy