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Physiological versus clinical consequences of left recurrent laryngeal neuropathy (LRLN)
Author(s) -
SEEHERMAN H. J.,
EHRLICH PAULA J.,
MORRIS ELISABETH
Publication year - 1995
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/j.2042-3306.1995.tb04881.x
Subject(s) - medicine , aerobic exercise , treadmill , horse , ventilation (architecture) , exercise intolerance , cardiology , biology , heart failure , paleontology , mechanical engineering , engineering
Summary The clinical implications of ventilatory alterations induced by left recurrent laryngeal neuropathy (LRLN) are reduced performance due to increased metabolic requirements for breathing and a reduction in peak aerobic power (V̇O 2peak ). To test this hypothesis, the metabolic cost of locomotion (MCL) and peak aerobic power (V̇O 2peak ) were measured in 4 non racing crossbred horses (low V̇O 2peak ) with reversibly induced LRLN using an incremental treadmill exercise test. Reversible LRLN was achieved with regional anaesthesia. These results were compared to previous measurements in 4 Thoroughbred racehorses (high V̇O 2peak , Ehrlich et al. 1993). No significant difference in MCL (based on V̇O 2 and venous lactate) was found in either group of horses at exercise intensities where V̇O 2 < V̇O 2peak (<9 m/s). Peak aerobic power decreased by 15.3% (140.0 ± 3.2 vs. 165.3 ± 3.4 ml/kg/min ± s.e., in the Thoroughbred racehorses (high V̇O 2peak ) with induced LRLN but not in the non racing horses with lower V̇O 2peak (135.0 ± 4.5 ml/kg/min ± s.e. The results of these 2 studies indicate that alterations in ventilation due to LRLN cause a significant reduction in V̇O 2peak only in horses with high V̇O 2peak . At exercise intensities where V̇O 2 < V̇O 2peak , MCL was not increased in either group of horses despite ventilatory alterations induced by LRLN.