Oper
ation
31
5
5.3.6 Dynamic and static pressures
FCV
®
results in a dynamic ventilation cycle with a pressure plateau phase at the end of
expiration only once every 10 cycles. With the exception of that moment, the intratracheal
pressures are measured dynamically and are therefore not always equal to the static (and
mean global alveolar) pressures.
As indicated in figure 5.7, at the end of inspiration the dynamic intratracheal pressure (Peak)
is higher than the static (and mean global alveolar) pressure. At the end of expiration, the
dynamic intratracheal pressure (EEP) is lower than the static (and mean global alveolar)
pressure.
The absolute discrepancy in pressure between the dynamic intratracheal pressures and static
(and mean global alveolar) increases with higher airway resistance and/or higher inspiratory
and expiratory flow.
It is recommended to confirm proper ventilation pressure settings by judging the plateau
pressure displayed every 10 cycles in the intratracheal pressure curve.
Figure 5.7 Dynamic tracheal pressures and schematic range of mean alveolar pressure
Inspiration
Expiration
Inspiration
Expiration
Inspiration
Expiration
Pressure
Intratracheal Pressure (dynamic)
Intratracheal Pressure (static)
Schematic range mean alveolar pressure
