Different contributions from lungs and chest wall to respiratory mechanics in mice, rats, and rabbits
Changes in lung mechanics are frequently inferred from intact-chest measures of total respiratory system mechanics without consideration of chest wall contribution. The participation of lungs and chest wall in respiratory mechanics has not been evaluated systematically in small animals commonly used...
Elmentve itt :
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| Dokumentumtípus: | Cikk |
| Megjelent: |
2019
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| Sorozat: | JOURNAL OF APPLIED PHYSIOLOGY
127 No. 1 |
| doi: | 10.1152/japplphysiol.00048.2019 |
| mtmt: | 30709079 |
| Online Access: | http://publicatio.bibl.u-szeged.hu/16489 |
| Tartalmi kivonat: | Changes in lung mechanics are frequently inferred from intact-chest measures of total respiratory system mechanics without consideration of chest wall contribution. The participation of lungs and chest wall in respiratory mechanics has not been evaluated systematically in small animals commonly used in respiratory research. Thus, we compared these contributions in intact-chest mice, rats and rabbits, and further characterized the influence of positive end-expiratory pressure (PEEP). Forced oscillation technique was applied to anesthetized, mechanically ventilated healthy animals to obtain total respiratory system impedance (Zrs) at 0, 3 and 6 cmH2O PEEP levels. Esophageal pressure was measured by a catheter-tip micromanometer to separate Zrs into pulmonary (ZL) and chest wall (Zcw) components. A model containing a frequency-independent Newtonian resistance (RN), inertance (I) and a constant-phase tissue damping (G) and elastance (H), was fitted to Zrs, ZL, and Zcw spectra. The contribution of Zcw to RN was negligible in all species and PEEP levels studied. However, the participation of Zcw in G and H was significant in all species and increased significantly with increasing PEEP and animal size (rabbit > rat > mice). Even in mice, the chest wall contribution to G and H was still considerable, reaching 47.0±4.0[SE]% and 32.9±5.9% for G and H, respectively. These findings demonstrate that airway parameters can be assessed from respiratory system mechanical measurements. However, the contribution from the chest wall should be considered when intact chest measurements are used to estimate lung parenchymal mechanics in small laboratory models (even in mice), particularly at elevated PEEP levels. |
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| Terjedelem/Fizikai jellemzők: | 198-204 |
| ISSN: | 8750-7587 |