Abstract
We determined the effect of breathing cold dry air (−39°C, 0.1% relative humidity, RH) and warm humid air (43°C, 100% RH) on airway mucosal blood flow (Q̇ aw) in normal human subjects ( n = 8, age 25–53 years) at rest. Q̇ aw was measured with a dimethylether uptake technique which reflects blood flow in the mucosa of large airways corresponding to a 50 ml anatomical dead-space segment extending distally from the trachea. Mean Q̇ aw was 10.1 ± 1.9 ml min −1 (mean ± S.D.) during room air breathing (25°C, 70% RH) and decreased to 4.7 ± 2.1 ml min −1 during cold dry air breathing ( p < 0.05). Within 20 min of resuming room air breathing, mean Q̇ aw had returned to baseline. Breathing warm humid air had no significant effect on mean Q̇ aw (8.2 ± 1.4 ml min −1). These results indicate that quiet breathing of frigid air causes vasoconstriction in central airways.
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 callDisclaimer: 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.
