Figure 4-10. Single Limb Patient Circuit Without Exhalation Valve - Covidien Puritan Bennett 560 User Manual

Installation and Assembly
5. Place a water trap (item 3) between the outlet port of the humidifier and the patient end.
6. Place a vented (NIV) interface to the end of the patient circuit. (item 5)
For both types of circuits, shown previously, you should connect the end of the proximal pressure tube as close
as possible to the patient (at the mask or cannula entry, if possible) so that the ventilator can account for all
load losses due to the circuit and its potential accessories. If this is not possible, it is best to modify the PATIENT
DISCONNECTION triggering threshold by doing one of the following: set a Max VTI alarm limit for pressure
modes or a Min VTE alarm limit for all ventilation modes if using a dual limb circuit.
As a reminder: Ensure that the length and the internal volume of the patient circuit are compatible with the
tidal volume: ringed tube Ø 22 mm for adults and ringed tube Ø 15 mm for pediatric patients with tidal vol-
umes lower than 200 ml. Use, if necessary, a 22F-15M link on the outlet and a 15M-22M link on the exhala-
tion block for a double limb circuit.
Warning
When using non-invasive ventilation (NIV), without an exhalation valve, use a vented nose or
face mask or a non vented combined with a leak accessory. When using non-invasive ventilation
(NIV), with an exhalation valve, use a non vented mask.
The level of inspiratory resistance of the circuit and accessories (bacteria filter, humidifier, and
so on) must be as low as possible. Settings—particularly the PATIENT DISCONNECTION alarm,
High inspired volume (High VTI), and Low inspired volume (Low VTI) settings—must be
periodically adjusted according to changes in the patient circuit resistance—especially when
filters are replaced.
Resistance of the exhalation valve and accessories (water traps, filters, HMEs etc) must be as
low as possible.
The exhalation valve must allow rapid discharge of the circuit pressure. Ensure that the
exhalation valve is always clean and its evacuation aperture (exhaust port) is never obstructed.
Do not start ventilation until you ensure that the device is suitably assembled, that the air inlet
filter is properly installed and is not obstructed, and that there is proper clearance all around
the unit. Also ensure that the patient circuit is suitably connected to both the ventilator and the
patient and that the patient circuit, including all hoses, is not damaged or obstructed.
Adding accessories to the ventilator breathing circuit, such as a humidifier and water trap(s),
may result in a decrease in tidal volume delivered to the patient due to the added compressible
volume of the accessory. Always assure that the patient is receiving the appropriate inspired
volume when altering the breathing circuit configuration.
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Figure 4-10. Single limb Patient Circuit Without Exhalation Valve

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User's Manual