Ventilator Performance - CareFusion LTV 1200 Service Manual

Ventilator Performance

Symptoms
Ventilator is auto
cycling, monitored
volumes are very
small, and RT XDCR
DATA item FTx
shows negative flows
during exhalation and
positive flows during
inspiration.
Ventilator won't allow
patient to exhale.
Set pressure not
reached and turbine
is humming.
Turbine sounds like
inspiration even
during exhalation.
p/n 18603-001, Rev. J
Possible Causes
Sense lines are reversed.
Diaphragm installed
backwards or incorrectly
seated in exhalation valve.
Sense lines occluded,
pinched or reversed.
Internal flexible tubing
occluded or pinched.
Internal flexible tubing has
pinhole leaks or leaking at
connections.
Defective exhalation drive
solenoid.
Bypass flexible tube
pinched.
Pinhole leaks in bypass
flexible tube.
®
LTV 1200, 1150, and 1100 Ventilator Service Manual
What to Do
The sense lines are not designed to be
removed from either the wye or the Luer
fittings. If the sense lines have been
removed and replaced incorrectly, they
may not seal correctly when replaced.
Replace the patient wye and sense lines
with a known good assembly.
Open the exhalation valve and remove the
diaphragm. Reseat the diaphragm and
snap the valve cap back in place. See
Cleaning the Reusable Exhalation Valve
and Patient Circuit in Chapter 4 for a
diagram of the exhalation valve assembly.
Check high and low pressure sense lines
to be sure they are correctly attached and
securely seated at both the ventilator and
wye ends.
Verify lines are not occluded or pinched.
This problem will often be accompanied
by XDCR FAULT alarms. Open the vent
and verify that none of the flexible tubes
connected to the solenoid manifold or
analog board are pinched or leaking. See
Internal Flexible Tubing on page 8-33
Replace the solenoid manifold. See
Solenoid Manifold Assembly in Chapter 8
for instructions.
If the bypass flexible tube is pinched, it
can usually be seen pressed against the
louver openings in the bottom of the
ventilator case.
Open the ventilator and remove the back
panel. Replace the back panel being sure
to fit the louvers in between the upper and
lower loop of the bypass flexible tube
before seating the back cover.
If the bypass flexible tube is leaking,
replace it.
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