Suspicion of Postanesthetic Femoral Paralysis of the Non-Dependent Limb in a Horse

Recovery after General Anaesthesia in Adult Horses: A Structured Summary of the Literature

Simple Summary

Recovery is the most dangerous phase of general anaesthesia in horses. Numerous publications have reported about this phase, but structured reviews that try to reduce the risk of bias of narrative reviews/expert opinions, focussing on the topic are missing. Therefore, the aim of the present article was to publish the first structured review as a summary of the literature focussing on the recovery phase after general anaesthesia in horses. The objective was to summarise the available literature, taking into account the scientific evidence of the individual studies. A structured approach was followed with two experts in the field independently deciding on article inclusion and its level of scientific evidence. A total number of 444 articles, sorted by topics and classified based on their levels of evidence, were finally included into the present summary. The most important findings were summarised and discussed. The present structured review can be used as a compilation of the publications that, to date, focus on the recovery phase after general anaesthesia in adult horses. This type of review tries to minimise the risk of bias inherent to narrative reviews/expert opinions.

Abstract

Recovery remains the most dangerous phase of general anaesthesia in horses. The objective of this publication was to perform a structured literature review including levels of evidence (LoE) of each study with the keywords “recovery anaesthesia horse”, entered at once, in the search browsers PubMed and Web of Science. The two authors independently evaluated each candidate article. A final list with 444 articles was obtained on 5 April 2021, classified as: 41 “narrative reviews/expert opinions”, 16 “retrospective outcome studies”, 5 “surveys”, 59 “premedication/sedation and induction drugs”, 27 “maintenance with inhalant agents”, 55 “maintenance with total intravenous anaesthesia (TIVA)”, 3 “TIVA versus inhalants”, 56 “maintenance with partial intravenous anaesthesia (PIVA)”, 27 “other drugs used during maintenance”, 18 “drugs before/during recovery”, 18 “recovery systems”, 21 “respiratory system in recovery”, 41 “other factors”, 51 “case series/reports” and 6 “systems to score recoveries”. Of them, 167 were LoE 1, 36 LoE 2, 33 LoE 3, 110 LoE 4, 90 LoE 5 and 8 could not be classified based on the available abstract. This review can be used as an up-to-date compilation of the literature about recovery after general anaesthesia in adult horses that tried to minimise the bias inherent to narrative reviews.

Transient pelvic limb neuropathy following proximal metatarsal and tarsal magnetic resonance imaging in seven horses

BACKGROUND

Pelvic limb neuropathy is a rare post-anaesthetic complication. In the authors' experiences, the incidence of post-anaesthesia neuropathy is increased following MRI of the proximal metatarsus and tarsal regions when compared with previously reported incidences of post-anaesthetic neuropathy.

OBJECTIVES

This study reports the incidence, diagnosis, treatment and outcome of seven horses with post-anaesthesia neuropathy following proximal metatarsal and tarsal MRI.

STUDY DESIGN

Retrospective case series.

METHODS

Case record review of horses receiving general anaesthesia for MRI between 1 January 2012 and 31 December 2017.

RESULTS

A total of 1134 MRI procedures were performed and reviewed for analysis. Eight cases of neuropathy were identified in 1088 limb scans (0.74%). Of these cases, one was subsequent to thoracic limb imaging (1/834; 0.12%) and seven were subsequent to imaging of proximal metatarsal and/or tarsal structures (7/181; 3.9%). Following proximal metatarsal and/or tarsal MRI, transient nondependent limb femoral neuropathy developed in six of the seven affected horses, with one additional horse developing peroneal neuropathy of the dependent limb. Recovery of pelvic limb function occurred within 72 h and 9 days in six and one horse, respectively.

MAIN LIMITATIONS

Anaesthetic protocol and neuropathy treatment for the affected horses were not standardised.

CONCLUSIONS

Though an uncommon complication in horses, transient neuropathy may occur more frequently following MRI of the proximal metatarsal and tarsal structures when compared with other MRI scans. This may be due to patient positioning and the requirement for limb traction for MRI of more proximal regions. Supportive care facilitates rapid return to function.