Title: Effects of lung volume on lung and chest wall mechanics in rats
Abstract: To investigate the effect of lung volume on chest wall and lung mechanics in the rats, we measured the impedance (Z) under closed- and open-chest conditions at various positive end-expiratory pressures (0–0.9 kPa) by using a computer-controlled small-animal ventilator (T. F. Schuessler and J. H. T. Bates. IEEE Trans. Biomed. Eng. 42: 860–866, 1995) that we have developed for determining accurately the respiratory Z in small animals. The Z of total respiratory system and lungs was measured with small-volume oscillations between 0.25 and 9.125 Hz. The measured Z was fitted to a model that featured a constant-phase tissue compartment (with dissipation and elastance characterized by constants G and H, respectively) and a constant airway resistance (Z. Hantos, B. Daroczy, B. Suki, S. Nagy, and J. J. Fredberg. J. Appl. Physiol. 72: 168–178, 1992). We matched the lung volume between the closed- and open-chest conditions by using the quasi-static pressure-volume relationship of the lungs to calculate Z as a function of lung volume. Resistance decreased with lung volume and was not significantly different between total respiratory system and lungs. However, G and H of the respiratory system were significantly higher than those of the lungs. We conclude that chest wall in rats has a significant influence on tissue mechanics of the total respiratory system.
Publication Year: 1999
Publication Date: 1999-01-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 131
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