Extracorporeal Membrane Oxygenation (ECMO) Sweep Gas Oxygen Fraction with In-line Nitric Oxide
Version 1.2.1
Sweep gas settings
Gas entering the INOMAX injector
800
ppm source
% O₂
21%100%
L/min
0.110 L/min
ppm
080 ppm
Oxygen entering oxygenator
97.5%
100% mixer oxygen diluted by 20 ppm nitric oxide carrier gas
Flow to oxygenator
4.898 L/min
Carrier gas added
0.128 L/min
Flow before sampling
5.128 L/min
Unable to calculate
Sampling correction
Nominal INOMAX sample withdrawal
−0.23 L/min
Sampling occurs after gas mixing, so it changes the estimated sweep flow reaching the membrane but not the mixed oxygen fraction.
No clinical values are intentionally saved by this control.
Equations
Q_NO = (C_set × Q_base) / (C_cylinder − C_set)Q_mixed = Q_base + Q_NOF_O2,final = F_O2,mixer × Q_base / Q_mixed = F_O2,mixer × (800 − C_set) / 800The added INOMAX carrier gas is nitrogen, so it dilutes oxygen. The simplified oxygen-fraction result is independent of base sweep flow when the delivery system achieves the selected nitric oxide concentration using an 800 ppm cylinder.
Q_oxygenator = Q_mixed − 0.23 L/minUses the nominal INOmax DSIR Plus patient-gas sampling flow of 230 mL/min. Because the sample is assumed to be removed after complete mixing, representative sample withdrawal changes total downstream flow but not gas composition.