Thesis
Duration of action provided by prilocaine and other local anaesthetic agents in equine palmar digital nerve blocks
Masters by Research, Murdoch University
2022
Abstract
Knowledge of local anaesthetic (LA) duration of action guides agent selection and aids interpretation of diagnostic nerve blocks in lameness examinations. Previously, generalisations for different agents have been inferred from work in other species, however in each scenario species and block specific neuroanatomic and volumerelated factors are expected to affect duration for each agent. This thesis further examined the duration and efficacy of common LAs used by equine practitioners for palmar digital nerve blocks (PDNB).
The first phase compared the duration of skin desensitisation over the heel bulbs after PDNB with bupivacaine, lidocaine, mepivacaine and prilocaine. Twelve horses received PDNBs in a complete, randomized crossover design. Force gauge measurement of skin sensitivity showed prilocaine (mean 102 min) and mepivacaine (107 min) provided significantly longer skin desensitisation than bupivacaine (53 min), which was significantly longer than lidocaine (25 min).
The second phase induced a reversible lameness in 12 horses. An inertial sensor system and force gauge quantified lameness and skin sensitivity after PDNB. Historical data collected similarly for mepivacaine was reanalysed. Prilocaine resolved lameness in 9/12 horses and mepivacaine in 8/8 horses. Skin desensitization in prilocaine and mepivacaine occurred significantly earlier (mean 10 min) than lameness resolution (28 min prilocaine, 40 min mepivacaine). Duration of lameness resolution was not different (100 min prilocaine, 128 min mepivacaine). Return to baseline lameness was significantly delayed for mepivacaine (345 min) but not prilocaine (156 min). Mepivacaine may more consistently achieve complete lameness resolution, however prilocaine provides a more concise period of efficacy which is useful when more specific blocks are intended within a region on the same day.
Details
- Title
- Duration of action provided by prilocaine and other local anaesthetic agents in equine palmar digital nerve blocks
- Authors/Creators
- Michaela M Harcourt
- Contributors
- Giselle Hosgood (Supervisor)Rachael Smith (Supervisor)Mieghan Bruce (Supervisor) - Murdoch University, Centre for Biosecurity and One Health
- Awarding Institution
- Murdoch University; Masters by Research
- Identifiers
- 991005568769107891
- Murdoch Affiliation
- School of Veterinary Medicine
- Resource Type
- Thesis
- Note
- Research Masters with Training (MVSurg) of Murdoch University
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