10.5 Pressure Control (PC)
In Pressure Control the system delivers
breaths with a constant preset pressure, with
a decelerating flow during a preset inspiratory
time, and at a preset frequency.
The following parameters are set:
1. PC above PEEP (cmH
2
O, solid line
in illustration above)
2. Respiratory Rate (b/min)
3. PEEP (cmH
2
O, dotted line in
illustration above)
4. I:E ratio / Insp. time
5. Inspiratory rise time (%/s)
6. Trigg. Flow / Trigg. Pressure
7. Gas mix (O
2
/Air or O
2
/N
2
O)
8. O
2
concentration (%)
9. Fresh gas flow (l/min)
10. Agent concentration (%)
The delivered volume is dependent upon the
pressure above PEEP, lung compliance and
resistance in the patient tube system and
airways. This means that the Tidal Volume can
vary. Pressure Control is preferred when there
is leakage in the breathing system e.g. due to
uncuffed endotracheal tube or in situations
when the maximum airway pressure must be
controlled.
The patient can trigger extra breaths.
Additionally, inspiration can be interrupted if
the patient attempts to exhale, provided the
generated pressure is more than 3 cmH
2
O
above the set pressure level. As the delivered
tidal volume can vary it is very important to
set alarm limits for Minute Volume to adequate
levels.
The flow during inspiration is decelerating, i.e.
the flow decreases as the pressure in the lungs
approaches the set PC above PEEP.
FLOW-i 4.2, User's Manual
213
| Ventilation modes |
10 |