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Effects of inhalation of albuterol sulphate, ipratroprium bromide and frusemide on breathing mechanics and gas exchange in healthy exercising horses
Author(s) -
BAYLY W. M.,
SLOCOMBE R. F.,
SCHOTT H. C.,
HINES M. T.,
SIDES R. H.,
HAKALA J. E.
Publication year - 2001
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 - 10.2746/042516401776249741
Subject(s) - ipratropium bromide , bronchodilator , inhalation , medicine , anesthesia , inhaler , bronchodilation , metered dose inhaler , ventilation (architecture) , respiratory rate , respiratory minute volume , heart rate , asthma , respiratory system , blood pressure , mechanical engineering , engineering
Summary The possibility that pre‐exercise inhalation of a bronchodilator by healthy horses could improve their mechanics of breathing and enhance performance was investigated. Ipratropium bromide (0.35 μg/kg bwt; n = 7) was administered by nebulisation 30 min before exercise and frusemide (1 mg/kg bwt; n = 6) was given in the same manner 2 h before exercise. Albuterol sulphate (360 and 720 μg; n = 7) were administered with a metered dose inhaler 2 h before exercise. Each drug was investigated independently of the others using cross‐over protocols. Horses completed incremental exercise tests and oxygen consumption, carbon dioxide production, arterial blood gases, heart rate and measures of breathing mechanics including total pulmonary resistance (R L ) and nasopharyngeal resistance (R U ) were determined for each exercise intensity. The resistance of the lower airways was calculated subsequently from the difference between R L and R U . None of the drugs tested had an effect on any of the variables measured, possibly because maximal bronchodilation is stimulated in healthy horses by the normal sympathoadrenergic response to exercise. Therefore, the pre‐exercise inhalation of a bronchodilator by a healthy horse is unlikely to improve performance capacity.