Mallinckrodt INOmax DSIR Plus MRI Operation Manual page 38

Effect of the INOmax DS
There are two main effects of connecting and using
the INOmax DS Plus MRI in a ventilator breathing
IR
circuit.
1.The INOmax DS Plus MRI adds NO/N
IR
breathing circuit in proportion to the NO setting
and the ventilator flowrate. For example, at an NO
setting of 20 ppm with an 800 ppm NO cylinder, the
INOmax DS Plus MRI adds 2.5% more gas to that
IR
delivered by the ventilator and proportionally less
for lower NO settings.
2.The INOmax DS Plus MRI subtracts gas from the
IR
breathing circuit via the gas sampling system at a
nominal flow rate of 0.23 L/min.
These two effects of adding and subtracting gas
from the ventilator breathing circuit have the
following effects:
Oxygen Dilution
The INOmax DS Plus MRI adds gas to the
IR
breathing circuit in proportion to the NO setting as
described above. The NO/N
ventilator gas dilutes the oxygen in proportion to
the set INOMAX dose. At the INOMAX dose setting
of 20 ppm, the added gas is 2.5%. Thus, the O
concentration is reduced by 2.5% of its original value.
For example, if the original O
v/v, then the O value after injection, at the maximum
2
setting, is 58.5% v/v.
Set Dose (ppm)
800 ppm Cylinder
80
40
20
1-28
Plus MRI in a ventilator circuit
IR
gas to the
2
mixture added to the
2
2
concentration was 60%
2
Oxygen Dilution % v/v
10
5
2.5
Minute Volume
When using volume ventilation with the
INOmax DS Plus MRI, the measured tidal volume
IR
delivered to the patient shows small changes
depending on the NO setting being used due to the
addition and subtraction of gases by the delivery
system. Some minor ventilator adjustments to the
minute volume may be required. The net result of
the INOmax DS Plus MRI on the delivered minute
IR
ventilation can be calculated as follows:
If the patient's minute ventilation is 10 L/min
(500 cc X 20 breaths/min)
The additional minute volume due to the INOMAX
can be calculated as follows:
INOMAX dose x Minute Volume
Cylinder Concentration -- INOMAX Dose
For a dose of 20 ppm (800 ppm cylinder) the
additional volume would be
(20 X 10) ÷ (800 – 20) = 0.26 L/min
To calculate the net change in minute volume:
0.26 L/min INOMAX added - 0.23 L/min removed
(sample system) = 0.03 L/min (net change)
This formula may be used when calculating the
changes to continuous flow on continuous flow
ventilators as well (using the continuous flow in
place of minute ventilation).
Trigger Sensitivity
The addition and subtraction of gases by the
INOmax DS Plus MRI may affect the trigger
IR
sensitivity of the ventilator when using synchronized
modes of ventilation. This may cause the ventilator
to auto-trigger in ventilators which have flow trigger
modes, especially where the trigger flow is set to
less than one L/min. The trigger sensitivity of the
ventilator should be checked after connecting the
INOmax DS Plus MRI delivery system.
IR
Additional INOMAX volume
=
added per minute
Part No. 20568 Rev-02
2015-08