Liposomal bupivacaine caudal epidural in horses results in adverse effects without analgesia.
Authors: Stokes Christopher, Natalini Claudio Correa, Wills Robert, Eddy Alison, Mochal-King Cathleen, O'Shea Caitlin, Fontenot Robin L
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Liposomal Bupivacaine Caudal Epidural in Horses Researchers investigated whether liposomal bupivacaine could provide analgesia when delivered via caudal epidural catheter in horses, a route that might theoretically extend pain relief to the caudal region without systemic effects. Ten healthy adult horses received 10 mL of 1.3% liposomal bupivacaine through a 15 cm indwelling epidural catheter, with mechanical nociceptive threshold testing performed over 72 hours using pressure algometry at four anatomic sites, whilst physical examination parameters and faecal/urinary output were monitored every four hours. Contrary to expectations, the treatment produced no measurable analgesia at any location or time point, yet generated significant clinical complications: ataxia scores increased markedly between 24 and 36 hours post-injection, two horses became recumbent, three required urinary catheterisation for retention, and six needed manual rectal evacuation for impaction. For equine practitioners considering regional anaesthetic techniques, this finding is sobering—liposomal bupivacaine via caudal epidural offers neither the intended analgesia nor the safety profile necessary for clinical use at this dose, and alternative agents or routes should be prioritised when pain management in the caudal region is required.
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Practical Takeaways
- •Do not use liposomal bupivacaine for caudal epidural analgesia in horses—it causes ataxia and serious side effects without providing pain relief
- •If considering epidural techniques, be aware that liposomal formulations may have different pharmacokinetics than conventional preparations and require separate validation
- •Horses receiving caudal epidurals require close monitoring for urinary retention and impaction; this study documents higher-than-expected complication rates with this specific drug
Key Findings
- •Liposomal bupivacaine (1.3%, 10 mL) via caudal epidural produced no significant analgesic effects at any anatomic site over 72 hours
- •Ataxia scores were significantly elevated from 24-36 hours post-injection
- •Adverse effects included recumbency (2/10), urinary retention requiring catheterization (3/10), and decreased fecal output (6/10)
- •No significant changes in vital parameters (temperature, heart rate, respiratory rate) compared to baseline