Examining the analgesic effect of ultrasound guided Pectoral Blocks on analgesic opioid consumption after surgical removal of breast tissue.

This study's uniqueness is in the quantification of the analgesic effect of regional anesthesia on its influence to reduce the use of opioid substances, and the variety of side effects associated with them, which has yet to been described in literature.

This is a prospective, observational,single center study which will be conducted at the Rabin Medical Center (Beilinson Campus), Petach Tikva, Israel, a tertiary university hospital. Sixty women undergoing breast tissue resection under general anesthesia will be enrolled after filling out an informed consent form.

As standard protocol in our hospital all participants will include women undergoing the surgery under general anesthesia, and the an addition of regional PEC block anesthesia.

The use of opioid substances during surgery will be done under the discretion of the anesthesiologist, according to accepted professional criteria.

All participants will undergo the the PEC block before surgery under general anesthesia under aseptic conditions, which is the standard analgesia protocol in our department.

Ultrasound guided PECS Block will be performed by identifying the thoracic muscles. Following the identification, the investigator will inject the anesthetic solution which will contain the conventional 25 cc of Bupivacaine 0.25-0.5% .

The concentration is determined by the upper dose limit to 2 mg / kg 11.

At the end of the operation all participants will be transferred to the post anesthesia recovery supervision unit, as standard protocol. The women will receive analgesic treatment according to accepted recovery unit protocols of Beilinson Hospital, and according to the professional discretion of the anesthesiologist in charge of the recovery unit.

On postoperative day one all participants will be asked to fill out a questionnaire that measures the degree of their pain after surgery, and the extent of the expected side effects from exposure to opioids This questionnaire is based on a questionnaire measuring quality QoR recovery from general anesthesia.

Inclusion Criteria:

Women over 18 who undergo breast tissue resection under general anesthesia at Beilinson Hospital, and are able to comply with the study's protocol

Exclusion Criteria:

1. Lack of patient's consent or lack of patient's ability to provide consent.
2. Known hypersensitivity to local anesthetic or to opioid, which will affect the nature of the pain management therapy in these patients.
3. Existing evidence of infection or gangrene on the thorax which prevents implementation of regional anesthesia - .
4. Known coagulation disorder.

Women above 18 undergoing breast tissue resection under general anesthesia at Beilinson Hospital