| 5. Ventilation Systems - Automatic and
Manual
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| 5.1
Perform leak test -
Ventilator circuit
- Selector switch set to Ventilator - all flows set
to minimum, occlude Y-piece
- Fill bellows with O2 flush - pressure
does not exceed 15 cm H2O - release
flush
- Set selector switch to Bag/APL and remove
occlusion at Y-piece - ventilator bellows does
not drift downward
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- defective ventilator pop-off valve - should
release when > 2.5 cm H2O
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| 5.2
Test automatic ventilation system
- Place a second breathing bag on the Y-piece
- Set O2 flow to 250 ml/min and other
gas flows to zero - set appropriate ventilator
parameters for next patient
- Set selector switch to Ventilator, turn
ventilator ON and fill bellows with O2
flush
- Inspiration - bellows delivers correct
tidal volume; expiration - bellows fills
completely
- Volume monitor is consistent with
ventilator
- Proper action of unidirectional valves
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- pop-off valve does not close to allow bellows to
fill completely
- bellows housing not fastened tightly
- drive gas hose not firmly attached
- connection from absorber to bellows is leaking
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- volume sensor cartridge faulty
- valves stick or do not seat properly
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- Remove breathing bag from Y-piece while
ventilator is still working
- Low pressure alarm sounds until breathing
bag is replaced
- Turn ventilator OFF
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- alarm faulty OR ventilator senses pressure 4 - 9
cm H2O with breathing bag off -
obstruction somewhere?
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| 5.3 Test manual
ventilation system
- Switch to Bag/APL mode
- Ventilate manually and assure inflation and
deflation of artificial lungs and appropriate
feel of system resistance and compliance
- Remove second breathing bag from Y-piece
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- faulty APL valve - incorrect pressure adjustment
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