Expiratory LAP
In the patients under sedation, the inspiratory LAP was easily
influenced by a decline in the intra thoracic pressure, however, the
expiratory LAP theoretically would not. Therefore, the expiratory LAP in
patients under sedation was thought to be almost identical to the LAP in
those in an awake state.
The expiratory LAPs after the ASV were slightly lower than those before
the ASV. From the aspect of the mechanism of noninvasive positive
pressure ventilation, a positive expiratory pressure might reduce the
venosus return and decreased the LAP. However, whether a positive
expiratory pressure influences the LAP immediately after the initiation
of the ASV remains unclear and requires further investigation in terms
of the hemodynamic status.