Liposomal Bupivacaine Vs Bupivacaine with Dexmedetomidine in Erector Spinae Plane Blocks for Mastectomies

This study compares two types of nerve-blocking pain medications used after mastectomy (breast removal surgery): standard bupivacaine combined with dexmedetomidine versus liposomal bupivacaine (a longer-acting form). The goal is to find out which provides better pain control and reduces the need for opioid painkillers after surgery. **You may be eligible if...** - You are scheduled to undergo any type of mastectomy, with or without lymph node removal - You agree to receive a peripheral nerve block for pain management - Your surgical and pain management teams agree a nerve block is appropriate for you **You may NOT be eligible if...** - You have declined a nerve block or study participation - You have an allergy to local anesthetics - You have an active infection at the nerve block site - You have pre-existing nerve problems in the area where the block would be placed - Your surgical team has decided a nerve block is not appropriate for you Talk to your doctor to see if this trial is right for you.