Liposomal bupivacaine provides longer duration analgesia than bupivacaine hydrochloride in an adjustable sole-pressure model of equine lameness.
Authors: V. Moorman, L. Pezzanite, G. Griffenhagen
Journal: American journal of veterinary research
Summary
# Editorial Summary Moorman, Pezzanite and Griffenhagen (2022) investigated whether liposomal bupivacaine could extend the duration of perineural analgesia compared to standard bupivacaine hydrochloride in horses with experimentally induced sole-pressure lameness. Six research horses underwent crossover testing where palmar nerve blocks were administered at the level of the proximal sesamoid bones, with lameness objectively quantified using inertial sensors, mechanical nociceptive threshold testing, and force platform analysis at intervals up to 72 hours post-injection. Liposomal bupivacaine demonstrated significantly superior analgesia, maintaining improvements in nociceptive threshold, lameness scores and peak vertical force for up to 24 hours, whilst the standard hydrochloride formulation provided measurable relief for only 1 hour post-injection. These findings suggest that the liposomal encapsulation—which slows drug release—warrants further clinical investigation as a means of extending nerve block duration in working horses requiring prolonged pain relief, potentially reducing the need for repeated injections during lameness management and diagnostic analgesia procedures.
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Practical Takeaways
- •Liposomal bupivacaine offers a clinically meaningful advantage for nerve blocks in lame horses, providing pain relief for a full day versus only 1 hour with standard bupivacaine—valuable for diagnostic anesthesia and therapeutic pain management
- •Consider liposomal bupivacaine for palmar nerve blocks when extended analgesia is needed, though cost-benefit and drug availability should be evaluated against standard formulations
- •This experimental finding warrants clinical validation in field cases before changing current anesthetic protocols
Key Findings
- •Liposomal bupivacaine (LB) provided significantly improved mechanical nociceptive thresholds, objective lameness, and peak vertical force for up to 24 hours post-injection
- •Bupivacaine hydrochloride (BHCl) showed significant improvements only at 1 hour post-injection
- •LB demonstrated 24-fold longer duration of analgesia compared to BHCl in perineural anesthesia of palmar nerves
- •The sole-pressure lameness model required screw adjustment every 24 hours to maintain grade 3/5 lameness throughout the study period