Study of cough in anaesthetized cats with experimental pulmonary oedema

The authors studied parameters of laryngopharyngeal (LPh) and tracheobronchial (TB) cough (the number of efforts--NE, the number of efforts per minute--NE.min-1, the intensity of the maximum effort--IME and the intensity of the attack--IA), respiratory parameters (VT, f, Cdyn), blood gas values (PaO2, PaCO2) and the pH in the arterial blood of anaesthetized cats (Pentobarbital Spofa, 35 mg x kg-1 i.p. with experimental pulmonary oedema. Oedema was induced by the i.v. administration of a fatty acid mixture (capric acid 3.8 g, caprylic acid 3.1 g and olive oil 3.0 g)--in a dose of 0.05 ml x kg-1 in group 1 and of 0.01 ml x kg-1 in group 2. Cough was elicited by stimulating the laryngopharyngeal and tracheobronchial mucosa with a silon fibre. Pulmonary oedema was determined from a macroscopic and microscopic examination of the lungs, from the ratio of lung weight to body weight and from the percentual dry weight of the right lungs. The authors found that the intensity of cough was depressed during pulmonary oedema, particularly in the case of TB cough. VT and Cdyn fell, f rose and the PaO2 and pH values steadily decreased.