Abstract
We describe a pulse-flow method of measuring static lung compliance (CL) that is sensitive to rapid transients in CL. CL is measured by blowing air at a constant flow into the mouth and lungs for 2 s and calculated by dividing airflow in 1/s by the change in transpulmonary pressure in CMH2O/s. Pulse and static inspiratory CL was measured in five normals, four obstructives, five obese, and two patients with pulmonary fibrosis, Pulse CL after tidal breathing was correlated with static CL measured after deep breaths (r = 0.96). Pulse CL after deep breaths was higher than pulse CL after tidal breathing (p less than 0.01) and then static CL after deep breaths (p less than 0.05). In all subjects the lower the forced expiratory volume in 1 s, expressed as a percentage of vital capacity (FEV1/FVC), the greater the increase in pulse CL after a deep breath will be (r = 0.93). After deep breaths pulse CL fell from maximum CL to base-line CL at a rate related to 1/t2 where t equals the time in seconds from the last deep breath. We conclude that the increase in CL after a deep breath is related to the degree of airway obstruction and that the subsequent fall in CL is related to 1/t2.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of applied physiology: respiratory, environmental and exercise physiology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
