Quick Reference Guide Primus
Infinity Empowered
SW 4.5n
31
Principles of Operation
Pressure Support Mode (optional)
Press. Support
is a pressure-assisted ventilation mode
for patients with spontaneous breathing. Synchroniza-
tion and pressure support for the spontaneous breath-
ing efforts are controlled by the sensitivity of the flow
trigger and by the level of
Δ
P
PS
(A). The rate at which
the pressure curve rises is pre-set by the rise time
T
SLOPE
(B).
The maximum inspiratory time for a spontaneous
breathing stroke varies according to age: 1.5 seconds
for patients aged 4 years and younger, and 4 seconds
for patients over 4 years.
Inspiration is ended as soon as the current inspiration
flow drops below 25% of the inspiratory peak flow. Any
leakage is compensated simultaneously by means of
the actual airway pressure.
099
25 %
25 %
Pressure
Trigger
Trigger indicator
Δ
P
PS
Flow
T
SLOPE
Time [s]
1/
Freq
MIN
1/
Freq
MIN
Apnea
ventilation
Flow trigger
Time [s]
Flow trigger
No trigger