SLE 5000 - Patient Circuits

Page 106
18.2.0.4 In TTV
plus
some of the breaths exceed
the set TTV
plus
. Why?
The spontaneous patient effort may exceed the set
volume. The rise time may be set in such a way that
the pressure waveform overshoots and the
ventilator measures the peak pressure.
18.2.0.5 Why is there no SET value for MAP and
Delta P in HFO mode?
The rate and changing lung mechanics make the
setting of MAP and dP unpredictable. There are
guidelines as to what values should be aimed for,
and these will be continually adjusted in accordance
with the changing lung mechanics and clinical
observation
18.3 Patient Circuits
18.3.0.1 What is the difference between the
BC2188/400 and BC5188/400 patient
circuit?
The difference between the two circuits is the
restrictor. The BC2188/400 patient circuit has a
purple restrictor, calibrated for 5 l/min fresh gas and
is suitable only for the SLE2000 and SLE2000 HFO
ventilators. The BC5188/400 patient circuit has an
yellow restrictor, calibrated for 8 l/min fresh gas and
is suitable only for the SLE4000 and SLE5000
ventilators.
18.3.0.2 Why is a restrictor necessary?
The function of the restrictor is to create a back
pressure in the inspiratory limb which creates the
leak and block alarms when there is a drop in
pressure
18.3.0.3 What happens if the restrictor is placed
in the expiratory limb instead of the
inspiratory limb?
There will be a fixed pressure of 20mbar in the
expiratory limb i.e. 20mbar PEEP/CPAP. However,
the restrictor is now moulded into the inspiratory
limb in single use circuits.
18.3.0.4 Should bacterial filters be used on the
expiratory limb?
SLE recommends the use of a single use bacterial
filter on the expiratory limb as a way of preventing
contamination of the ventilator and the environment.
It does need to be changed every 24hrs, or if wet at
any time. A wet bacterial filter will no longer filter
bacteria and will also cause an increase in pressure.
As diligent changing of the filter cannot be
guaranteed, the exhalation block should still be
autoclaved after every use.
18.3.0.5 When using the INOSYS Nitric Oxide
therapy and the ventilator what
scavenging filters do I need?
When using NO it is recommended that 2 sets of
scavenging filters are used. This solves the issue of
any build up of pressure and fluctuating Mean
Airway Pressures. A hose assembly is fitted to the
end of the exhalation block. The hose assembly has
a bifurcated “Y” connection and the scavenging
filters are attached to each hose.
18.3.0.6 How often does the exhalation block
and silencer need to be autoclaved?
Both the exhalation block and the silencer need
autoclaving after each patient. The silencer can be
autoclaved up to 25 times. Thereafter the plastic
ends may become brittle and crack.
18.3.0.7 How do I clean the exhalation block
and scavenging system after using
NO?
All patient circuitry must be single use. This includes
the bifurcated hose assembly. The scavenging
filters may be used until the soda lime granules turn
from pink to a brownish colour and then they must
be replaced. The exhalation block must be rinsed
before being sent for autoclaving. Deposits of NO
and NO
2
may have built up during use. During
steam autoclaving these deposits, due to the
combination of the deposits and steam, will form
nitrous oxide. This in turn will eat into the metal of
the exhalation block leaving “rust” like markings.