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1. Switch the unit ON. The compliance menu will be displayed.
The patient airway fl ow sensor head must be in the patient circuit
in order to carry out compliance compensation.
2. Select Yes to Compliance Compensation and follow the instructions
on screen instructions
The ventilator delivers a breath of known volume to the breathing circuit, records
the pressure (cmH
2
O) achieved and verifi es that a leak is not present.
3. The dead space is calculated as follows:
This value is retained in memory until the ventilator is switched off or retested.
4. When the ventilator is set to use on a patient and when the
ventilation is stable, the total compliance of system and patient
(Ct) is measured. The TV can then be increased to compensate for
the volume lost due to compression within the breathing system.
The increase in tidal volume is calculated by the formula:
For example:
A system test measurement at a TV of 200 ml gave a pressure rise of 25 cmH
2
O.
Running the ventilator on a patient with a set 500ml TV gave a peak pressure
of 20cmH
2
O.
= dead space compliance (C
3
)
Volume (mL)
Pressure (cmH
2
0)
C
t
C
s
C
s
-
Set TV * (
1 + ) = new TV (mL)
C
s
=
= 8
25cmH
2
O
200mL
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