title: Effects of inhaled ipratropium bromide on breathing mechanics and gas exchange in exercising horses with chronic obstructive pulmonary disease.
abstract: Six Warmblood horses suffering an acute exacerbation of COPD were tested to investigate whether inhalation of ipratropium bromide (IB) dry powder (2,400 microg) 30 min preexercise would improve their exercise capacity. A cross-over protocol with an inert powder placebo (P) was used. Mechanics of breathing and arterial blood gases were determined before treatment, after treatment but pre-exercise, and during an incremental exercise test. Oxygen consumption (VO2) was also measured before and during exercise, and the time to fatigue recorded. Inhalation of IB reduced total pulmonary resistance (RL) and maximum intrapleural pressure changes (deltaPpl(max)) and increased dynamic compliance before exercise. The onset of exercise was associated with a marked decrease in RL in P-treated horses but not those receiving IB, so that RL during exercise was not affected by treatment. Although deltaPpl(max) was lower at 8,9 and 10 m/s with IB, there were no treatment-related changes in VO2, blood gases, time to fatigue or any other measurement of breathing mechanics. Therefore, although inhalation of IB prior to exercise may have improved deltaPpl(max), it had no apparent impact on the horses' capacity for exercise.
authors.affiliation: Department of Veterinary Clinical Sciences, Washington State University, Pullman, USA.
authors.forename: W M
authors.initials: WM
authors.lastname: Bayly
authors.forename: D H
authors.initials: DH
authors.lastname: Duvivier
authors.forename: D
authors.initials: D
authors.lastname: Votion
authors.forename: S
authors.initials: S
authors.lastname: Vandenput
authors.forename: T
authors.initials: T
authors.lastname: Art
authors.forename: P
authors.initials: P
authors.lastname: Lekeux
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols; D000818:Animals; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D018592:Cross-Over Studies; D005080:Exercise Test / Q000662:veterinary; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D009241:Ipratropium / Q000008:administration & dosage* / Q000627:therapeutic use; D009330:Nebulizers and Vaporizers; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010805:Physical Conditioning, Animal; D011312:Pressure; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000662:veterinary*; D011659:Pulmonary Gas Exchange / Q000187:drug effects* / Q000502:physiology; D015656:Respiratory Mechanics / Q000187:drug effects* / Q000502:physiology
chemical_list: D000336:Aerosols; D001993:Bronchodilator Agents; D009241:Ipratropium