Maquet SERVO-air, Руководство пользователя

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5.2 Pressure Control (PC)
Pressure Control (PC):
• delivers a constant pressure over a preset
inspiratory time and at a preset respiratory
rate
• delivers the inspiration with a decelerating
flow
• changes in lung or thorax resistance or
compliance will affect the volume delivered
1 2 3 4
5 6 7
The following parameters are set:
1. Oxygen concentration (%)
2. PEEP (cmH
2
O)
3. Respiratory rate (b/min)
4. PC above PEEP (cmH
2
O)
5. I:E ratio or Inspiration time (s)
6. Inspiratory rise time (% or s)
7. Trigger
Refer to section Settings on page 43.
The delivered volume is dependent on the
pressure above PEEP, lung compliance and
resistance in the patient circuit and airways.
This means that the tidal volume can vary.
The flow during inspiration is decelerating. The
patient can trigger extra breaths. As the
delivered tidal volume can vary, it is very
important to set alarm limits for the minute
volume to adequate levels.
PC ventilation is often preferred when there is
leakage in the patient circuit, e.g. due to an
uncuffed endotracheal tube, or in situations
where the maximum airway pressure must be
controlled.
If a patient tries to exhale during inspiration,
pressure increases. When it increases
3 cmH
2
O above the set inspiratory pressure
level, the active expiratory valve opens and
regulates the pressure down to the set
inspiratory pressure level. If the pressure
increases to the set upper pressure limit, e.g.
if the patient is coughing, the expiratory valve
opens and the ventilator system switches to
expiration.
SERVO-air Ventilator System v2.2, User's Manual
59
| Ventilation modes | 5 |