Mallinckrodt INOmax DSIR Plus MRI Operation Manual page 39

Circle Anesthesia Ventilator Systems
The use of the INOmax DS
anesthesia ventilator systems (which use volume
ventilation causes small changes in the delivered
minute volume as noted previously (see Minute
Volume, page 1-28).
Recirculation of INOMAX in circle breathing
systems should be avoided. The gas in the
ventilator bellows may also contain undesirable
levels of NO which may not be removed by the
2
CO absorbent.
2
Recirculation of gases may lead to a rapid increase
in INOMAX dose levels creating a shutdown of the
INOmax DS Plus MRI. This can be avoided by
IR
using a fresh gas flow rate equal to or above that
of the patient's minute volume. This will ensure that
there is sufficient fresh gas in the absorber such
that no accumulated gas from the ventilator bellows
reaches the patient through the inspiratory limb of
the breathing circuit.
Maximum NO Delivery
The INOmax DS Plus MRI is limited to a
IR
maximum NO flow of 6.35 L/min. Maximum
deliverable dose is 80 ppm (800 ppm cylinders)
when the breathing gas flow is 60 lpm or less.
Breathing gas flows greater than 60 L/min. will
reduce the delivered dose (resulting in a lower
monitored NO value). See the graph below for
estimated dosing based on breathing gas circuit
flow rate.
1. Maximum deliverable NO concentration (ppm)
2. Constant inspiratory flowrate (L/min)
Part No. 20568 Rev-02
2015-08
Plus MRI with circle
IR
When intermittent inspiratory flow rates are used,
peak ventilator flows which exceed 120 L/min
may be achieved. Peak inspiratory flow rates
are transient and extremely short in duration.
As a result, the portion of the breath which is
not matched by the INOmax DS
extremely small and the effect on the delivered
concentration of NO within the entire range of the
breath is small.
Does acid form in the humidifier or breathing
circuit when delivering INOMAX?
A long term test was performed at Datex-Ohmeda
to determine if acid would build up in a breathing
circuit over time when delivering inhaled Nitric
Oxide.
The test equipment was a Sechrist IV-100B
neonatal ventilator and a Fisher Paykel MR500
humidifier. The ventilator settings were Rate 40
breaths per minute, Flow 6 L/min and Oxygen
100% v/v and the humidifier was set to 36
degree's C.
The pH level was measured at the humidifier (the
water in the humidifier chamber), at the patient
Y (the condensate in the breathing circuit) and
at the exhalation valve back at the ventilator (the
condensate in the breathing circuit).
For the test distilled water was used which had an
initial pH of 5.75 and the pH was measured with
Hydrion Paper (4.5 to 7.5).
A control test without NO being delivered was run
initially to see if the pH would change over time
due to the slightly acidic nature of distilled water.
The control test was run for six days with no
change in the pH at any of the test points.
The test was then repeated with 80 ppm of NO
being delivered continuously for nine days with
the pH being tested daily at each of the test
points. There was no change of pH at any of the
test points for any of the daily tests.
Plus MRI is
IR
1-29