A modeling-based evaluation of isothermal rebreathing for breath gas analyses of highly soluble volatile organic compounds
Julian King, Karl Unterkofler, Gerald Teschl, Susanne Teschl, Pawel Mochalski, Helin Koç, Hartmann Hinterhuber, and Anton Amann
This model allows for a mechanistic analysis of various rebreathing protocols suggested in the literature. In particular, it predicts that the end-exhaled levels of acetone and methanol measured during free tidal breathing will underestimate the underlying alveolar concentration by factor of up to 1.5. Moreover, it clarifies the discrepancies between in vitro and in vivo blood-breath ratios of hydrophilic VOCs and yields further quantitative insights into the physiological components of isothermal rebreathing and highly soluble gas exchange in general.
Keywords: breath gas analysis, volatile organic compounds, highly soluble gas exchange, rebreathing, blood-breath ratio, acetone, methanol, modeling