L'examen endoscopique dans le diagnostic des affections des cavités nasales

in Association des Vétérinaires du Hainaut - Charleroi - 1989 (1989)

Influence of Inertance on Measurements of the Mechanical Properties of the Bovine Respiratory System

in Veterinary Research Communications (1988), 12(1), 61-66

The observation that dynamic compliance (Cdyn) tended to rise with respiratory frequency (f) in adult cattle led us to reassess the importance of inertial pressures in measuring Cdyn in large animals ... [more ▼]

The observation that dynamic compliance (Cdyn) tended to rise with respiratory frequency (f) in adult cattle led us to reassess the importance of inertial pressures in measuring Cdyn in large animals. Five healthy Friesian cows were selected for their ability to show an increase of f without significant change in tidal volume (VT). Dynamic compliance was measured three times, both at the resting f (21 +/- 1 cpm), and at higher f (49 +/- 3 cpm), obtained by an artificial increase in the dead space of the breathing mask. Frequency-response characteristics of the measuring instruments were matched up to 12 Hz. The inertia of the lungs and gas stream (In) was calculated as the ratio of the accelerative pressure change to the simultaneous change in volume acceleration. Inertance was also estimated from the dimensions of the bovine airways and from the relative linear flow velocities reported by Rohrer (1915). Dynamic compliance measured during rapid breathing was significantly higher (p less than or equal to 0.01) than base-line values. Dynamic compliance was strongly correlated with f (r = +0.96). Measured and estimated In were 0.002 and 0.003 kPa.sec2.L-1 respectively. Dynamic compliance did not differ significantly from base-line values when it was corrected for the estimated inertance effect. [less ▲]

Mechanical properties of excised calf lungs: effects of airway obstruction with beads

in Research in Veterinary Science (1987), 42(3), 277-279

Isolated lungs of five calves were suspended in an airtight box used as a ventilator. Lungs were ventilated from the outside at different levels of transpulmonary pressure. Dynamic compliance (Cdyn) and ... [more ▼]

Isolated lungs of five calves were suspended in an airtight box used as a ventilator. Lungs were ventilated from the outside at different levels of transpulmonary pressure. Dynamic compliance (Cdyn) and total pulmonary resistance (RL) were measured. These pulmonary function values were also measured during central and peripheral airway obstructions. It was demonstrated that both central and peripheral obstructions induced significant variations of Cdyn and RL. However, decrease of Cdyn was greater and increase of RL was smaller during a peripheral obstruction than during a central one [less ▲]

Mechanical properties of excised calf lungs

in Research in Veterinary Science (1987), 42(3), 272-276

Five isolated calf lungs were suspended in an airtight box used as a ventilator. Lungs were ventilated from the outside at different levels of transpulmonary pressure (Ptp). The static pressure-volume ... [more ▼]

Five isolated calf lungs were suspended in an airtight box used as a ventilator. Lungs were ventilated from the outside at different levels of transpulmonary pressure (Ptp). The static pressure-volume curve characteristics of the lungs were measured. Static compliance (Cstat) was 1.9 +/- 0.37 litres kPa-1 or 25 +/- 5 per cent of total lung capacity kPa-1. At a Ptp of 0.7 kPa, dynamic compliance (Cdyn) and lung resistance (RL) were 1.1 +/- 0.1 litres kPa-1 and 0.126 +/- 0.02 kPa litres sec-1, respectively. Both an increase and a decrease of this level of Ptp induced an increase of RL and a decrease of Cdyn. The ratio Cdyn/Cstat averaged 57 +/- 0.8 per cent. It was concluded that in excised lungs, Cdyn is lower in the calf than in a number of other species and that pulmonary function values measured in vitro are optimum at values of Ptp close to values recorded in vivo in healthy cattle [less ▲]

Pulmonary function changes induced by experimental dichlorvos toxicosis in calves

in Research in Veterinary Science (1986), 40(3), 318-321

Clinical and pulmonary function changes induced by intravenous dichlorvos (2,2-dichlorvinyldimethyl phosphate) (DDVP) toxicosis, and reversibility of these changes after atropine treatment were ... [more ▼]

Clinical and pulmonary function changes induced by intravenous dichlorvos (2,2-dichlorvinyldimethyl phosphate) (DDVP) toxicosis, and reversibility of these changes after atropine treatment were investigated in six Friesian calves one to three months old. From one minute after dosage, all animals showed severe respiratory distress, excitation, weakness, muscle fasciculation and cholinesterase inhibition. Decrease in dynamic lung compliance and arterial oxygen tension and increase in total pulmonary resistance, viscous work of breathing and alveolar arterial oxygen gradient were highly significant (P less than 0.01). On the other hand, body secretions, heart rate, respiratory rate, tidal volume and arterial carbon dioxide tension were not significantly affected by DDVP injection. Atropine promptly and completely reversed these changes, except for muscle fasciculations, central depression and cholinesterase inhibition which disappeared progressively within 24 hours. [less ▲]

Detectie, pathogenese, en etiologie van longfunctieveranderingen by de verouderende hond, met speciale aandacht voor het surfactant systeem

in Fungo Dwarsverband V.O. Retraite - Eymond-Ville - Netherlands - Novembre 1985 (1985, November)

High-frequency ventilation in cats: technical data

in 4th Comparative Respiratory Society meeting - Anaheim California - USA (1985)