Perform a comparison of effective pain relief duration between liposomal bupivacaine and dexmedetomidine when added to bupivacaine in a block for mastectomy for cancer surgery. The erector spinae plane block is a well-established block that is utilized for post operative pain control for procedures performed on the soft tissue of the chest and chest wall as well as intrathoracic procedures. The goal is comparison of the effective duration of both study groups to determine if there is a significant difference in time and amount of post operative opioids required which admitted to hospital.

Performance of a single-blinded randomized control trial to evaluate effectiveness of postoperative pain control in erector spinae plane blocks with bupivacaine with liposomal bupivacaine as the control versus bupivacaine with dexmedetomidine. Plan to randomize patients by alternating months, so that odd months' patients will receive bupivacaine 0.25% with liposomal bupivacaine in the erector spinae plane block. Even months patients will receive bupivacaine 0.25% with dexmedetomidine in the erector spinae plane block.

Block will be performed with ultrasound by the Acute Pain Service team. A time out confirming location of surgery, allergies, consents completed prior to start of the block. Patients will be monitored with 5 lead electrocardiography, non-invasive blood pressure, and pulse oximetry. After skin wheal with 1% lidocaine via 25-27 g needle and echogenic 20 g needle will be utilized to perform the block. The needle will be placed under direct ultrasound visualization into the erector spinae plane. The plane will be hydro dissected with normal saline to confirm needle tip has accessed the erector spinae plane. The local anesthetic will be given in a total of 0.2 ml/kg up to 20 mls (selected based on the study group placement) and aspiration will occur every 5 mls during the block. This will be repeated on the second side if a bilateral block is indicated in based on the surgical consent. All patients will receive 10 mg IV dexamethasone post-induction of anesthesia.

While the patient is in patient pain scores and milligrams of morphine equivalence (MMEs) will be collected every 6 hours based on charting by the nurses providing care starting from time "0" in the PACU after surgery, up until discharge. Then to obtain pain scores up to 72 hours after surgery, patients will be called at home after 72 hours and asked what their pain scores had been daily since discharge and a total of tabs taken daily.

Inclusion Criteria:

• Patients requiring any variation of mastectomy with or without axillary lymph node dissection.
• Patient agrees to a peripheral nerve block.
• Patient agrees to be a study participant.
• APS team believes a peripheral nerve block would be appropriate for the patient after reviewing medical/surgical history.
• Surgeon agrees with the block plan by APS.

Exclusion Criteria:

• Patient declines a peripheral nerve block.
• Patient declines to be a study participant.
• APS team believes a peripheral nerve block is not clinically indicated.
• Surgeon does not want a peripheral nerve block.
• Patient has allergy to local anesthestic.
• Patient has an active infection at the site of the peripheral nerve block.
• Patient with pre-existing neural deficits along the distribution of the block.
• Patient with coagulopathy.
• Patient taking antithrombotic drugs outside the ASRA guidelines.
• Patients weight is less that 50 kg due to concerns for local anesthetic toxicity syndrome.

Patients will not be able to see overhear from the block team the type of drugs used in the block.