Effects of Pulmonary Fibrosis and Surface Tension on Alveolar Sac Mechanics in Diffuse Alveolar Damage.
J Biomech Eng
; 143(8)2021 08 01.
Article
in English
| MEDLINE | ID: covidwho-1169857
ABSTRACT
Diffuse alveolar damage (DAD) is a characteristic histopathologic pattern in most cases of acute respiratory distress syndrome and severe viral pneumonia, such as COVID-19. DAD is characterized by an acute phase with edema, hyaline membranes, and inflammation followed by an organizing phase with pulmonary fibrosis and hyperplasia. The degree of pulmonary fibrosis and surface tension is different in the pathological stages of DAD. The effects of pulmonary fibrosis and surface tension on alveolar sac mechanics in DAD are investigated by using the fluid-structure interaction (FSI) method. The human pulmonary alveolus is idealized by a three-dimensional honeycomb-like geometry, with alveolar geometries approximated as closely packed 14-sided polygons. A dynamic compression-relaxation model for surface tension effects is adopted. Compared to a healthy model, DAD models are created by increasing the tissue thickness and decreasing the concentration of the surfactant. The FSI results show that pulmonary fibrosis is more influential than the surface tension on flow rate, volume, P-V loop, and resistance. The lungs of the disease models become stiffer than those of the healthy models. According to the P-V loop results, the surface tension plays a more important role in hysteresis than the material nonlinearity of the lung tissue. Our study demonstrates the differences in air flow and lung function on the alveolar sacs between the healthy and DAD models.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Pulmonary Alveoli
/
Pulmonary Fibrosis
/
Mechanical Phenomena
/
Models, Biological
Type of study:
Experimental Studies
Limits:
Humans
Language:
English
Year:
2021
Document Type:
Article
Affiliation country:
1.4050789
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