The purpose of the study is to compare pain control after robotic hysterectomy surgery using either liposomal bupivacaine or Bupivacaine when injected during a transversus abdominis plane (TAP) block. Robotic hysterectomy is when a patient is electively having robotic assisted removal of one's uterus. Both medications liposomal bupivacaine and Bupivacaine are standard of care in these types of surgeries.

Treatment technique:

The patient will be in the supine position. The transversus abdominis muscle layer will be identified with the ultrasound. Using sterile technique, skin infiltration with 2% lidocaine will occur, 2 cm medial to the ultrasound probe. An 22g Nerve block needle will then be inserted and advanced under ultrasound guidance until it is below the fascial covering of the transversus abdominis muscle layer. Gentle aspiration for air, or blood will be performed and either 30 cc of 0.25% bupivacaine with 1/200,000 parts epinephrine or 30 mL of liposomal bupivacaine mixed 1:1 with normal saline will be injected under ultrasound guidance. For each 5cc of local anesthetic injected, aspiration will be performed. Upon completion of the injection, the needle will then be removed. This will then be completed on the contralateral side. The patient will be monitored in the preoperative area until he/she is brought into the operating room for their procedure.

When the operation is complete the patient will either be discharged home or brought to the ward where each day a member of the research team will evaluate the patient for signs of complications and ask the patient their minimum and maximum pain score.

If patients have met criterion for discharge to home including pain <4/10, independence of intravenous analgesia, and are stable for discharge medically, but are awaiting placement, the time of discharge for the purposes of the study will be the day they have met such criterion as opposed to the day of actual discharge, as this can vary depending on patient placement.

If the patient is discharged prior to 72 hours post injection, then the patient will receive one phone call at 24 hours post injection, 48 hours post injection , and 72 hours post injection +/- 5 hours. During this phone call the patient will be asked about pain score, narcotic use, overall satisfaction via a recorded patient questionnaire, quality of recovery via a quality of recovery survey, and assessed if any adverse events have occurred.

Adequate analgesia will be defined as <3 VAS at rest, and if VAS is greater than 3 adjustments in oral or intravenous pain medications will be given as determined by the nurse.

Inclusion Criteria:

• those who present for elective robotic assisted hysterectomy

Exclusion Criteria:

• non english speaking
• chronic pain
• on opioids greater than 1 weeks
• chronic anticoagulation
• allergy to local anesthetics
• use of spinal or epidural for surgery
• lack of patient cooperation
• contraindication to regional anesthesia