Can sedation be used for equine lameness investigation?

Helene Termansen,Lucinda Meehan

doi:10.18849/ve.v6i2.373

Helene Termansen, Lucinda Meehan

Open Access

https://doi.org/10.18849/ve.v6i2.373

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Abstract

PICO question In horses undergoing lameness investigation, does sedation with a2-adrenergic agonists alone versus sedation with a2-adrenergic agonists in combination with butorphanol tartrate effect the degree of lameness?  Clinical bottom line Category of research question Diagnosis The number and type of study designs reviewed Six papers were critically reviewed. There were two crossover clinical studies, three crossover controlled clinical studies and a randomised controlled clinical study Strength of evidence Moderate Outcomes reported There was limited evidence to suggest that xylazine and romifidine in combination with butorphanol has an effect on forelimb lameness and that detomidine has an effect on hindlimb lameness. Most evidence suggests that xylazine alone or in combination with butorphanol has no effect on the lameness Conclusion In general, sedating a horse with an a2-adrenergic agonist alone or in combination with butorphanol tartrate does not change the baseline degree of lameness. Due to the large variation in the measurements, the small magnitude of few significant effects and the inconsistency of these significant findings, there is insufficient evidence to recommend avoiding the use of sedation in cases where it would increase the safety of those involved. However, regardless of protocol used, clinicians must appreciate the possibility of individual horse variation  How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care. 

Highlights

N = 6 Grade 3–4/5 AAEP lameness grade unilateral forelimb lameness induced with set screws inserted into a custommade shoe
10 ml blood was collected by direct venipuncture for quantification of xylazine, acepromazine and mepivacaine at each time point
Inclusion: Lame horses or lameness induced, relevant to PICO question, clinical studies

Summary

Summary of the evidence

Population: Six adult horses with a lameness of grade 1/5 or less on a subjective lameness scale previously described by Ross (2011) (AAEP lameness scale):. Each horse received six treatments with a minimum washout of 7 days between trials: xylazine hydrochloride at 0.1 or 0.2 mg/kg IV, acepromazine maleate at 0.02 or 0.04 mg/kg IV, 1 ml saline IV, local analgesia (abaxial nerve block – 4 ml 2% mepivacaine hydrochloride). 10 ml blood was collected by direct venipuncture for quantification of xylazine, acepromazine and mepivacaine at each time point. The horses were assessed at time 0 (immediately after lameness induction) and [10, 30, 45] and 60 minutes posttreatment. Acepromazine (0.02 and 0.04 mg/kg) and xylazine (0.2 mg/kg) did not result in significant differences in objective lameness parameters at any time point

Limitations:

Findings

Methodology Section