How gas trapping at low lung volumes affect energy required to expand lung to total lung capacity?
Frazer-D; Tomblyn-S; McKinney-W; Friend-KA; Goldsmith-T
Ann Biomed Eng 2001 Oct; 29(Suppl 1):S143
When an excised lung is slowly ventilated, not all gas entering the lung during inflation can be removed during the following lung deflation. In order to develop a realistic model of the gas trapping process, it is important to determine the mechanical characteristics of the region of the lung where gas trapping takes place. In this study, excised rat lungs were inflated-deflated from the degassed state for two cycles between 30 cm H2O, defined as total lung capacity (TLC), and a minimum pressure of -5 cm H2O (PLmin). Then the lungs were ventilated between 60% TLC and PLmin at a slow continuous rate for 10 inflation deflation cycles. During this procedure, trapped gas accumulated in the lungs. The lung were then inflated to TLC and the increase in energy necessary to expand the lung compared to the second inflation-deflation cycle was determined. Results show that a significant increase in energy was required to expand the lungs containing trapped gas which accumulated as the lung was ventilated at low lung volumes when compared with the energy required to expand the lung during the second inflation-deflation cycle.
Lung-burden; Lung-disorders; Gases; Models; Laboratory-animals; Animals; Animal-studies; In-vitro-study
Abstract; Conference/Symposia Proceedings
Annals of Biomedical Engineering