Clinical and pharmacokinetic effects of regional or general anaesthesia on intravenous regional limb perfusion with amikacin in horses.
Authors: Mahne A T, Rioja E, Marais H J, Villarino N F, Rubio-Martinez L M
Journal: Equine veterinary journal
Summary
# Editorial Summary Intravenous regional limb perfusion (IV-RLP) with antimicrobials is a cornerstone technique for treating equine limb infections, yet the impact of anaesthetic choice on drug delivery and tourniquet efficacy remained unexplored. Researchers compared amikacin concentrations in serum and synovial fluid across three anaesthetic protocols—sedation alone, general anaesthesia, and regional anaesthesia combined with either sedation or general anaesthesia—using a crossover design in six horses receiving bilateral IV-RLP. General anaesthesia and regional anaesthesia both produced significantly higher synovial fluid amikacin concentrations than sedation alone, with regional anaesthesia conferring additional pharmacokinetic advantages including prolonged drug retention in the limb and reduced systemic absorption. These findings substantiate the clinical rationale for regional techniques: eliminating movement improves tourniquet seal and haemostasis, allowing superior antimicrobial penetration into target tissues. Practitioners should consider regional anaesthesia (particularly epidural or perineural blocks) as the preferred adjunct to IV-RLP for serious limb infections where maximising local drug concentration is critical, though the choice remains individualised based on case severity, anatomical considerations, and patient risk factors.
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Practical Takeaways
- •Choice of anaesthetic protocol (regional vs general) for IV-RLP procedures lacks evidence-based guidance; current practice is based on clinical assumption rather than data
- •Regional anaesthesia may offer practical advantage by reducing patient movement during tourniquet application and drug delivery, but this needs clinical validation
- •Veterinarians performing IV-RLP should recognize this is an area where evidence-based recommendations are not yet available and should base decisions on individual case factors
Key Findings
- •No scientific data currently exist on clinical and pharmacokinetic effects of anaesthetic protocols on antimicrobial IV-RLP in horses
- •Regional anaesthesia is hypothesized to improve tourniquet efficiency through decreased limb movement during IV-RLP procedures
- •Study addresses gap in knowledge regarding optimal anaesthetic management for IV-RLP with amikacin in equine patients