SLR - February 2021 - Sachi Patel

EXPAREL® (Long-Acting Liposomal Bupivacaine) Use for Popliteal Nerve Block in Postoperative Pain Control after Ankle Fracture Fixation

Reference: Discepola P, Bouhara M, Kwon M, Siddiqui BA, Whitwell TA, Sanghvi SY, Cook KD, Moore RE, Korban A, Eloy JD. EXPAREL® (Long-Acting Liposomal Bupivacaine) Use for Popliteal Nerve Block in Postoperative Pain Control after Ankle Fracture Fixation. Pain Res Manag. 2020 Jul 23;2020:5982567. doi: 10.1155/2020/5982567. PMID: 32774566; PMCID: PMC7396112.

Level of Evidence: 4 Case Series 

Scientific Literature Review

Reviewed By: Sachi Patel, DPM
Residency Program: NYU Langone Health and Hospitals System – Brooklyn, NY

Podiatric Relevance: This article is of interest to the podiatric surgeon to help determine if a different formulation of a commonly used anesthetic agent provides better, long lasting pain relief in the immediate postoperative state. The authors of this article have put forth this case series to discuss if Exparel, a liposomal Bupivacaine, provides better pain control when used for a postoperative popliteal nerve block. 

Methods: Four patients received a standard ultrasound guided popliteal nerve block pre-operatively. During the surgery, the patients were not given any narcotics, with the exception of fentanyl to aid in induction and thigh tourniquet pain. The patients were also not given any additional local anesthetic. Post operatively, the patients were monitored for neurologic and sensory deficits in targeted dermatomes, on arrival to the PACU, after 60 minutes and after 120 minutes. Additionally, VAS and RSS scores were obtained per the institutions PACU protocol, every five minutes for the first 15 minutes, every 15 minutes for the following hour, and then every 30 minutes until the patient was discharged. Upon discharge from the PACU, the patients were given Percocet every six hours while in the hospital, and the patients kept up documentation of medication consumption and pain at home. 

Results: Of the four patients in this case review three of the four were able to minimize their Percocet consumption, including two patients that did not require opioids in the immediate three postoperative days. The length of the block was noted to be varied, with one patient having an indeterminate block duration. A block was considered successful if the patient had loss of cold sensation in the dermatome of interest. There was a large degree of variability in the effects and the duration of the block, and a larger patient cohort is required to determine whether Exparel is an effective local anesthetic at controlling postoperative pain. 

Conclusions: The authors of the case study came to an inconclusive resolution, as there was a bimodal distribution of effectiveness of the popliteal block with Exparel. This case series was very interesting to potentially affect change in management of postoperative pain, though a larger patient cohort would have given more conclusive data. The lack of a larger patient population is recognized by the authors, and a larger study is in progress by the institution. An injectable anesthetic with predictable outcomes would be helpful for podiatric surgeons in managing pain expectations if the block was determined to be statistically significant. An effective regional block would also help to mitigate the need for stronger postoperative narcotics, as was seen in two patients of the study that did not require Percocet in the immediate three days after surgery.

Additionally, if a larger study is performed, surgeons would be able to have a data proven conversation with patients about pain expectations. It would be interesting to include additional data points including, but not limited too - giving IV Toradol post operatively, limiting patients to Tylenol and Mobic as the primary oral analgesics, even limiting the use of a tourniquet to eliminate an additional source of pain, or including the saphenous nerve in the block.

Educational Opportunities