Meta-analysis evaluating resting laryngeal endoscopy as a diagnostic tool for recurrent laryngeal neuropathy in the equine athlete

Elliott, S. and Cheetham, J.

Equine Vet J (2019) 51: 167–172

DOI: 10.1111/evj.12987

Abstract

BACKGROUND: Resting endoscopy has commonly been used as a method to predict laryngeal function at exercise. OBJECTIVES: To perform a meta-analysis to determine the sensitivity and specificity of resting laryngeal endoscopy to predict clinical recurrent laryngeal neuropathy at exercise. STUDY DESIGN: Meta-analysis. METHODS: Manuscripts were included if data were available for both resting and exercising airway function on all or a subset of horses. Normal resting endoscopy was defined as laryngeal grades 1 or 2 on a 4-/7-point scale or 1, 2 or 3 on a 5-point scale and normal dynamic endoscopy as a dynamic laryngeal grade A. RESULTS: Twelve studies including 1827 horses were evaluated. A small proportion of horses with grade 1 or grade 2 laryngeal function at rest, 3.5 and 11.9%, respectively, were identified as having abnormal laryngeal function at exercise. Within the horses with grade 3 laryngeal function at rest, 16% were classified as grade A, 26.4% as grade B and 57.6% as grade C at exercise. Worsening subgrades within resting grade 3 demonstrated an increasing proportion of complete or partial paralysis at exercise. The sensitivity and specificity of resting endoscopy was 74.4 and 95.1%, respectively, and the positive and negative predictive values were 85.6 and 90.5% respectively. MAIN LIMITATIONS: Use of two separate grading systems for evaluating resting laryngeal function. Other forms of dynamic airway collapse were not evaluated. CONCLUSIONS: Resting endoscopy is sensitive and highly specific for predicting laryngeal function at exercise. Dynamic endoscopy is important to assess multiple causes of airway collapse.

Citation

Elliott, S., & Cheetham, J. (2019). Meta-analysis evaluating resting laryngeal endoscopy as a diagnostic tool for recurrent laryngeal neuropathy in the equine athlete. Equine Vet J, 51(2), 167–172. https://doi.org/10.1111/evj.12987 Animals, Horses, respiratory, horse, exercise physiology, Horse Diseases/*diagnosis, Laryngeal Nerve Injuries/diagnosis/*veterinary, Laryngoscopy/*veterinary, Larynx, recurrent laryngeal neuropathy, Sports

Keywords

• Animals
• Horses
• respiratory
• horse
• exercise physiology
• Horse Diseases/*diagnosis
• Laryngeal Nerve Injuries/diagnosis/*veterinary
• Laryngoscopy/*veterinary
• Larynx
• recurrent laryngeal neuropathy
• Sports