Diamonds represent mean values for the 15 patients at 5 minutes interval throughout the study. At 35 min the knob on the ventilator panel for setting Tp was reset from 0 to 20 % to start Tp20. At 70 minutes Tp0late was started by turning the knob back to 0 %. Times for resetting are indicated with vertical interrupted lines. Data at 35 and 70 minutes represent the first breaths during Tp20 and Tp0late.
Panel A. Tidal elimination of CO2 (VtCO2) against time. For the 15 patients, diamonds and thin lines represent percent of mean value during Tp0init ±2 SE.
Panel B. Airway dead space (VDaw) against time in each subject, patients ventilated with heated humidifiers (continuous lines) or heat and moisture exchangers (broken lines). Diamonds shows mean VDaw.
Panel C. Slope of the alveolar plateau against time. For the 15 patients diamonds and thin lines represent percent of mean value during Tp0init ±2 SE.