Mallinckrodt INOMAX DSir Plus Operation Manual page 37

Circle Anesthesia Ventilator Systems
The use of the INOmax DS
ventilator systems (which use volume ventilation
causes small changes in the delivered minute
volume as noted previously (see Minute Volume,
page 1-24).
Recirculation of INOMAX in circle breathing systems
should be avoided. The gas in the ventilator bellows
may also contain undesirable levels of NO
may not be removed by the CO
Recirculation of gases may lead to a rapid increase
in INOMAX dose levels creating a shutdown of the
INOmax DS . This can be avoided by using a fresh
IR
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 is limited to a maximum NO flow of
IR
6.35 L/min. This means the maximum deliverable NO
concentration will vary based on the ventilator flow
rate. The maximum deliverable NO concentration will
vary from approximately 80 ppm at a constant flow
of 60 L/min to approximately 40 ppm at constant flow
120 L/min.
1. Maximum deliverable NO concentration (ppm)
2. Constant inspiratory flowrate (L/min)
Part No. 20717 Rev-01
2014-07
with circle anesthesia
IR
which
2
absorbent.
2
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 is extremely small and the
IR
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.
1-25