•PECS nerve blocks are widely used for post-op analgesia in breast reduction surgery.

•Liposomal bupivacaine (LB, Exparel) is a long acting bupivacaine that can extend the duration of PECS nerve blocks and is gaining popularity in regional anesthesia.

•Few data exists pertaining to the the effect LB in PECS blocks on pain control for breast reduction procedures.

•To investigate the effectiveness of PECs I & II blocks with LB and their effect on perioperative opioid use and pain scores compared to patients not receiving a nerve block and those receiving the block with plain local anesthetic.

•IRB Approval: VA Central IRB

•Study: Retrospective observational study

•Subjects: 127 patients undergoing breast reduction procedures from Jan 2011 to Feb 2023.

•Study groups: No peripheral nerve block, PECS blocks without LB, PECS block with LB.

•Primary outcome: Perioperative narcotic usage measured in oral morphine equivalents (OME).

•Secondary Outcome: Pain scores in PACU.

•Patients with PECS blocks with LB has significantly less narcotic requirements in the outpatient setting.

•No difference existed between the groups in the PACU opioid requirement.

•Patients with block with and without LB required less intra-op narcotic than patients without a block.

•There was no difference in pain scores between the three groups.