Local Wound Infiltration with Liposomal Bupivacaine Decreases Post-Cesarean Pain Scores

Introduction:
Surgical patients are routinely prescribed opioid analgesics that are strongly associated with drug overdose deaths. Liposomal bupivacaine is a long-acting local anesthetic that received FDA approval in 2011 for local surgical site infiltration to promote post-operative analgesia. This anesthetic has demonstrated an improvement in post-operative pain control in various surgical realms, indicating a decreased need for opiates and subsequently decreased risks. However, few studies have investigated its use at the time of cesarean delivery.

Methods:
In this retrospective study, patients for the liposomal bupivacaine group (LBG) were selected from patients who underwent a cesarean delivery (CD) between May 2019 and December 2019 and received intra-operative local wound infiltration with liposomal bupivacaine. Patients in the LBG were included if they were between 18 and 45 years of age, had a BMI < 60, and received liposomal bupivacaine as documented in the electronic medical record (EMR). Patients in the control group (CG) were selected as matched controls using the EMR and underwent a CD within one week of their matched LBG counterpart and were within three weeks of their gestational age at time of delivery. With the exception of the liposomal bupivacaine administration, patients in both groups received the standard post-operative care, which included intrathecal morphine. Comparisons were analyzed with t-test, Chi-square, or Fisher’s exact with SPSS.

Results:
Fifty-seven patients met LBG inclusion criteria. Fifty-nine matched control patients were selected from the EMR. Primary outcomes assessed in this study included patient opiate use in morphine-equivalent doses (MED) from 24 to 48 hours post-operatively and patient pain ratings via 11-point Likert Scale averaged every 12 hours. Patients in the LBG had lower MED in all post-operative time frames, though differences in MED were not statistically significant. Patients in the LBG had significantly lower pain scores in the 0-12 hour post-operative time frame (p < 0.01) and the 12-24 hour post-operative time frame (p < 0.01). In later post-operative time frames, patients in the LBG had equal or higher pain scores. Patients in both groups required similar doses of anti-emetics and alternative pain medications. Two patients in each group had chorioamnionitis. Two patients in the LBG had endometritis. One wound infection occurred in the LBG.

Conclusion:
This study demonstrates that local wound infiltration with liposomal bupivacaine at the time of CD can be beneficial in reducing pain scores in the post-operative period following CD. Drawbacks of this study include routine standard of care post-operative opiate pain medication administration, which could lead to lack of significant differences between LBG and CG MED. One potential concern with local wound infiltration is the risk of post-operative seroma and wound infection. In this study, only one patient in the LBG developed a post-operative wound infection, which was not statistically different than the CG. Future research should include a prospective randomized control trial investigating liposomal bupivacaine at the time of CD, head-to-head comparison of liposomal bupivacaine and intrathecal morphine, cost analysis of liposomal bupivacaine, and formal patient and nursing education on post-operative pain control administration and expectations.

References: Cherot, Elizabeth MD, MBA; Kett, Atilla MD, MBA; Mauro, Rachel MD Liposomal Bupivacaine at Cesarean Delivery, Minimizing Opioid use for Post-operative Pain Control [17J], Obstetrics & Gynecology: May 2018 - Volume 131 - Issue - p 112S-113S doi: 10.1097/01.AOG.0000533481.39090.65.

Parikh, P., Sunesara, I., Multani, S. S., Patterson, B., Lutz, E. & Martin Jr., J., N. (2019) Intra-incisional liposomal bupivacaine and its impact on postcesarean analgesia: a retrospective study, The Journal of Maternal-Fetal & Neonatal Medicine, 32:6, 966-970, DOI: 10.1080/14767058.2017.1397118.

Prabhu, Malavika MD; Clapp, Mark A. MD, MPH; McQuaid-Hanson, Emily MD; Ona, Samsiya MD; O'Donnell, Taylor BA; James, Kaitlyn PhD, MPH; Bateman, Brian T. MD, MSc; Wylie, Blair J. MD, MPH; Barth, William H. Jr MD Liposomal Bupivacaine Block at the Time of Cesarean Delivery to Decrease Postoperative Pain, Obstetrics & Gynecology: July 2018 - Volume 132 - Issue 1 - p 70-78 doi: 10.1097/AOG.000000000000264.