Standard and viscoelastic mechanical properties of respiratory system compartments in dogs: Effect of volume, posture, and shape.
Respir Physiol Neurobiol
; 261: 31-39, 2019 03.
Article
em En
| MEDLINE
| ID: mdl-30553944
ABSTRACT
In 9 anesthetized, paralyzed dogs lung and chest-wall standard (viscous resistance, Rint, and quasi-static elastance, Est) and viscoelastic parameters (resistance, Rvel, and time constant, τvel) were measured in the supine posture before and after rib-cage block, after application of an expiratory threshold load, and after 75° head-up tilting before and after wide chest opening. Lung and chest-wall τvel were the same under all conditions. Rvel was independent of volume and posture, and greater for the lung. Chest-wall Rint was independent of flow, volume, and posture. Lung Rint decreased with increasing volume. Chest-wall Rint, Est and Rvel increased with rib-cage block, allowing the assessment of both abdominal-wall and rib-cage characteristics. When chest opening did not elicit bronchoconstriction, the decrease of Rvel was â¼6%. Main conclusions:
lung and chest-wall exhibit linear tissue viscoelasticity within the range studied; rib-cage and abdomen characteristics are similar, and asynchronous motion is not expected at physiological respiratory rates; in normal lungs, heterogeneity of parallel time constants plays a marginal role.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Parede Torácica
/
Cães
/
Pulmão
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Respir Physiol Neurobiol
Ano de publicação:
2019
Tipo de documento:
Article