06-08-2015, 09:10 AM
(This post was last modified: 06-08-2015, 09:14 AM by VTSleeper.)
This is the recommendation from my titration study:
The patient should be changed to bi-level therapy with mask of choice, heated humidification and ramp at a pressure of 22/18 H2O. Alternatively and preferably auto BIPAP can be used with Imax 25 cm H2O, Emin 12 cm H2O and PS 4 cm H2O should be used.
Assuming that I get an auto BIPAP machine, what will the settings be and what will they actually mean especially as far as exhalation pressure is concerned? I am assuming that the lowest exhalation pressure will be 12 cm H2O. The PS 4 has me somewhat confused, though.
PS is pressure support - the amount of additional pressure provided when you inhale. EPAP is exhalation pressure, IPAP is inhalation pressure and PS is the difference. EP + PS = IP
So your settings would be:
Emin = minimum exhale pressure = 12 cm H2O
Imax = maximum inhalation pressure = 25 cm
PS = pressure support = 4 cm
You'll see these don't actually add up, so (depending on the particular machine) both EP and PS can be set to vary within limits. The EP will go up and down to support your airway against obstructive apnea and the PS will vary on top of that. Do you know what type of machine you will be getting?
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The PS=4 means that your IPAP (inhalation pressure) will always be 4 cm H2O higher than your EPAP (exhalation pressure). So if your EPAP is 12, your IPAP will be 16. If your EPAP goes up to 20 then your IPAP will be 24 etc. The IPAP will top out at 25, so your EPAP will top out at 21.
The range of 12-25 is a little wide open but should be OK for a start.
Sounds like you will be getting a good machine. Definitely hold out for the auto bipap.