Pulmonary distribution of aerosolized technetium Tc 99m pentetate after administration of a single dose of aerosolized albuterol sulfate in horses with recurrent airway obstruction. [Erratum: July 1999, v. 60 (7), p. 847.]

• Published in: American journal of veterinary research Vol. 60; no. 6; pp. 764 - 769
• Main Authors: Rush, B.R, Hoskinson, J.J, Davis, E.G, Matson, C.J, Hakala, J.E
• Format: Journal Article
• Language: English
• Published: United States 01.06.1999
• Subjects: Administration, Inhalation; Aerosols; Airway Obstruction - diagnostic imaging; Airway Obstruction - physiopathology; Airway Obstruction - veterinary; Albuterol; Animals; Bronchodilator Agents; bronchodilators; distribution; drug therapy; Female; Horse Diseases - diagnostic imaging; Horses; Lung - diagnostic imaging; Lung - drug effects; Lung - physiopathology; Male; Radionuclide Imaging; Recurrence; respiratory tract diseases; technetium; Technetium Tc 99m Pentetate - administration & dosage; Technetium Tc 99m Pentetate - pharmacokinetics
• ISSN: 0002-9645; 1943-5681
• DOI: 10.2460/ajvr.1999.60.06.764

To determine whether pulmonary distribution of aerosolized technetium Tc 99m pentetate is improved after inhalation of a single dose of albuterol sulfate in horses susceptible to recurrent airway obstruction (heaves). 6 horses with heaves and 4 horses with normal respiratory tract function. Images were obtained during ventilation of horses at baseline (maximal change in pleural pressure during tidal breathing [deltaPpImax] >15 cm H2O) and after aerosolized albuterol sulfate (360 microg) administration, with a 24-hour washout period between experiments. The deltaPpImax was determined prior to the baseline scan, prior to albuterol sulfate administration, and 5 minutes after albuterol sulfate administration. Images were assessed by visual inspection (semi-quantitative scoring system) and histogram analysis. Images obtained from horses with heaves had nonuniform pulmonary distribution of radionuclide characterized by poor penetration in peripheral lung fields and excess deposition in large airways. Histogram analysis of images of the caudal portions of the lungs revealed nonuniform radionuclide deposition in horses with heaves and uniform radionuclide deposition in control horses. Administration of a single dose of aerosolized albuterol sulfate improved pulmonary distribution of aerosolized radiolabeled pentetate suspension in horses with heaves but did not alter pulmonary distribution in clinically normal horses. Precedent bronchodilator administration may improve pulmonary distribution of aerosolized, surface-active anti-inflammatory preparations.