Abstract
Whole-body plethysmography (WBP) is an established method to determine physiological parameters and pathophysiological alteration of breathing in animals and animal models of a variety of diseases. Although frequently used, there is ongoing debate about what exactly is measured by whole-body-plethysmography and how reliable the data derived from this method are. Here, we designed an artificial lung model that enables a thorough evaluation of different predictions about and around whole-body plethysmography. Using our lung model, we confirmed that during WBP two components contribute to the pressure changes detected in the chamber: (1) the increase in the pressure due to heating and moistening of the air during inspiration, termed conditioning; (2) changes in the chamber pressure that depend on airway resistance. Both components overlap and contribute to the temporal pressure-profile measured in the chamber or across the wall of the chamber, respectively. Our data showed that a precise measurement of the breathing volume appears to be hindered by at least two factors: (1) the unknown relative contribution of each of these two components; (2) not only the air in the inspired volume is conditioned during inspiration, but also air within the residual volume and dead space that is recruited during inspiration. Moreover, our data suggest that the expiratory negative pressure peak that is used to determine the enhanced pause (Penh) parameter is not a measure for airway resistance as such but rather a consequence of the animal’s response to the airway resistance, using forced or active expiration to overcome the resistance by a higher thoracic pressure.
Highlights
Whole-body plethysmography (WBP) is an established method to determine physiological parameters and pathophysiological alteration of breathing in animals and animal models of a variety of diseases
Fenn devised a sealed chamber to measure tidal volume in infants[12]. They used the “barometric method” (PWBP) utilizing the pressure changes resulting from the warming of the inspired air and cooling during e xpiration[12] and assumed that at the end of inspiration the inspired air has been warmed to body temperature and humidified to saturation
We have compared the measurement of tidal volume ( VT) from anaesthetized mice using flow plethysmograph (FWBP) with 3D reconstructions of X-Ray micro-computer tomography data, and found that VT calculated from flow whole-body plethysmography (FWBP) are smaller as compared to volumes derived from the 3D reconstructions of μCT21
Summary
Whole-body plethysmography (WBP) is an established method to determine physiological parameters and pathophysiological alteration of breathing in animals and animal models of a variety of diseases. Fenn devised a sealed chamber to measure tidal volume in infants[12] They used the “barometric method” (PWBP) utilizing the pressure changes resulting from the warming of the inspired air (referred to as conditioning) and cooling during e xpiration[12] and assumed that at the end of inspiration the inspired air has been warmed to body temperature and humidified to saturation. Based on this assumption the tidal volume is calculated. It was speculated that the uncertainty in FWBP to define the zero-flow point limits the accuracy of the F WBP21
Sign-in/Register to view highlights & summary 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.
