Contributions of Loss of Lung Recoil and of Enhanced Airways Collapsibility to the Airflow Obstruction of Chronic Bronchitis and Emphysema

Changes in elastic fibres in the small airways and alveoli in COPD

“…These findings are consistent with the idea that in patients with COPD the loss of elastic tissue in the parenchyma leads to airflow obstruction. The decrease in expiratory flow rates in COPD are attributed to a reduction in alveolar driving pressure because of loss of elastic recoil, and to increases in airway resistance because of loss of elastic airway support [26,27]. A decrease in elastic fibres in the alveoli will contribute to the reduction in elastic recoil, while a loss of alveolar attachments to the airways will mean loss of support for the small airways and greater narrowing of the small airways in expiration.…”

Lung Distensibility and Airway Function in Asthmatic Children

“…In contrast to the static recoil airway conductance (PA,,-G,,) relationship investigated by several authors (16,25), the static recoil lung conductance plot includes lung tissue resistance (2,3). This component is more dominant the younger the subject is and the higher the subject's end-expiratory level approaches the full inspiratory position (2).…”

“…It was demonstrated several years ago that only the P s l~-G~ slope represents adequately the flow-resistive behavior of the lungs (5,25). In contrast to the static recoil airway conductance (PA,,-G,,) relationship investigated by several authors (16,25), the static recoil lung conductance plot includes lung tissue resistance (2,3).…”

“…Airflow limitation, the common functional characteristic of airway disease, can be due to a decrease in driving pressure (pulmonary elastic recoil), or intrinsic airway narrowing (4,5,17,18,(24)(25)(26)(27)34). Studies in adults have related the PV characteristics of the lung to structural alterations (17,18,30,37).…”

Assessing change in airway calibre‐measurement of airway resistance.

“…It also depends on the airway distending pressure which cannot be measured directly but which under quasi-static conditions appears to be closely related to static lung recoil pressure Mead, Takishima & Leith, 1970). Patients may therefore have increased airway resistance in the absence of intrinsic airway disease due to loss of lung recoil pressure (Leaver, Tattersfield & Pride, 1973).…”