PULMONARY-FUNCTION CHANGES INDUCED BY 3 REGIMENS OF BRONCHODILATING AGENTS IN CALVES WITH ACUTE RESPIRATORY-DISTRESS SYNDROME

Two aerosolised bronchodilators, one sympathomimetic and one parasympa tholytic, mere tested either alone or in combination for their ability to improve the pulmonary function of double-muscled calves suffering from acute respiratory distress syndrome. In control animals treated w ith 0.9 per cent saline the parameters of pulmonary function and signs of clinical distress did not change significantly within the hour fol lowing the first treatment. Among the other animals, both at one hour and seven days after the first treatment, the most clinical improvemen t was observed in the animals treated with both bronchodilators and th e least in the animals treated with clenbuterol hydrochloride. One hou r after the first treatment the respiratory system compliance of the a nimals treated with ipratropium bromide and the arterial oxygen tensio n of the animals treated with both bronchodilators were significantly enhanced. After seven days the resistive parameters, the rectal temper ature and the respiratory rate were also significantly improved in the animals treated with ipratropium bromide or both bronchodilators wher eas only the respiratory rate and rectal temperature were significantl y reduced in the animals treated with clenbuterol hydrochloride.