Efficacy of Extended-Release Liposomal Bupivacaine for Post-Partum Pain Management Following Obstetrical Laceration: A Prospective, Randomized, Single-Blinded Trial

All pregnant female subjects over the age of 18 eligible to deliver vaginally at WRNMMC will be screened for potential recruitment in our long-acting liposomal bupivacaine (Exparel®) postpartum pain medicine trial prior to admission for active labor or induction of labor. At the 36 or 38 week visit, all pregnant patients will receive an information sheet describing the study participation and they will be asked to consider participating in the study. At the time of admission, patients will be asked if they were provided the study information sheet and if they would like to consent to study participation. Discussion of the study will occur after the delivery consent form for obstetric services has been signed and when discussion of postpartum pain management is addressed. Those subjects who meet inclusion criteria for the study will be randomized to either the plain bupivacaine group or exparel group after vaginal delivery and identification of a second, third, or fourth degree laceration.

Potential study subjects will be informed that the purpose of the study is to evaluate the efficacy of two different formulations of bupivacaine, 0.25% plain bupivacaine and liposomal bupivacaine (Exparel®) on postpartum pain following repair of a second, third, or fourth degree laceration sustained during vaginal delivery. This medication is FDA (Food and Drug Administration) approved and is currently being used in our hospital by other surgical sub-specialties as part of a multi-modal approach to post-operative pain control.

If a potential subject chooses to participate, she will be randomized to one of two groups, either a 0.25% bupivacaine injection of total 20 ml or an injection of total 20 ml long-active liposomal bupivacaine that will be injected in the subject's perineum (the tissue between the opening of the anus and the vagina) at the completion of the case in the delivery room. Regardless of the decision to participate in the study or which treatment group assignment, all subjects will have the same options for partum pain medications. There is no monetary payment for joining the study and subjects may choose to leave the study at any point during the study without consequence. They will still receive the same high standard of care from our Service.

The study is designed as a single blind, randomized study. This means the subject will not know which group a subject is assigned to until completion of the study. Subjects may choose to have their allocated study arm disclosed at this time. Randomization will occur using a computer-generated randomization program carried out in the Investigational Pharmacy by Dr. Moussavian. Subjects will be randomly assigned to either receive the study medication or bupivacaine.

The primary goal of the study is to assess how effective the study medication is in providing adequate pain control following repair of a second, third, or fourth degree laceration; therefore, the subjects' post-partum pain will be assessed at various intervals following the repair. On post-partum day one, subjects will be asked questions regarding their pain level in the vaginal area according to an 11-point visual pain scale. Subjects will also be asked about their bowel movements and any associated pain, again, using the same visual pain scale. Subjects will also be asked to the impact the pain has on 4 quality of life measures using an 11-point visual pain scale. Subjects will also be called or contacted via email thru Relay Health on post-op day three and on post-op day seven to assess pain on those days. Part of the study's goal is to assess whether the study medication provides pain control for longer than the acute (24 hour) period. Subjects will be given a visual pain scale to go home with so that they can reference it during their post-operative phone or email follow ups. Additionally, subjects will be asked to gather their pain medication bottles in order to count out the remaining pills in each bottle. This will allow us to determine the amount of oral pain medication used since discharge from the hospital.