Pulmochart Reference (ver. 5.5)
Definition and calculation of respiratory volume parameters in the SPIRO app.

Respiratory volume parameters

Overview

The SPIRO app considers the inspiratory tidal volume (Vti), the expiratory tidal volume (Vte) and the leak.

Details

Inspiratory tidal volume (Vti (mL/kg))
Vti is the integrated tidal volume of the flow signal between the detected inspiratory and expiratory flow onsets. The integrated volume is divided by the patients body weight.

Expiratory tidal volume (Vte (mL/kg))
Vte is the integrated tidal volume of the flow signal between the detected expiratory and inspiratory flow onsets. The integrated volume is divided by the patients body weight.

Leak (%)
The leak of the flow is calculated as (Vti-Vte)/Vti *100%.
The leak is limited to values between -100% and 100%. Smaller or larger values arising e.g., from unexpected spontaneous breathing during ventilation are set to 0%. Furthermore values smaller than the leak threshold are set 0% (default threshold 5%).