jskinner wrote:Snoredog wrote:I think you got a good baseline, you must have had a couple beers or glass of wine with dinner last night it is much worse the prior nights, if so I would ignore last night's data..
Yeah last night wasn't good. The only change I made was that I changed rise time from 4 back down to its default of 3. That shouldn't have an effect should it?
No actually that shouldn't have come into play at all. Rise time is only applicable when you are in back up mode then backup mode has to be set from BPM=Auto to BPM=Fixed settings, then you input Rise Time and IT timed values. IF BPM=Auto it completely ignores any values input.
IF BPM=Auto is not correcting your breathing when landing in the backup mode, then you input those Fixed values. The goal with this machine is to get EPAP taking care of Obstructive Apnea (not necessarily obstructive hypopnea). Then the moving IPAP pressure adjusts Pressure Support to eliminate any Periodic Breathing. If any Central events show up it switches to the Backup Mode where those settings (in your case it is set to Automatic) slow breathing down (i.e. BPM) which brings the central dysregulation under control. Once spontaneous breathing returns (2 to 6 breaths supposedly) you breathe back on the spontaneous side of the machine.
You almost have to look at this machine like 3 machines in one. SV side corrects breathing, if it does that it can eliminate PB and Centrals. Central dysregulation is caused by erratic breathing or periodic breathing. So main function of the SV side is breathing. Backup mode (i.e. BPM=xxx) is another machine type that uses settings to control breathing from the Automatic side of the machine. If you understand the logic behind how they do titration decisions its easy to understand.
The periodic breathing is a series of breaths where there is a pattern of over shoot and under shoot. It is like after you have an apnea you gasp and take a deep breath (similar to holding breath under water in a swimming pool). But that deep recovery breath over shoots your oxygen/CO2 ratio and it continues. The target of this machine is catch your inspiration as it begins and apply Pressure Support by IPAP to bring the inspiration up so you avoid that recovery breath and overshoot. Many times you will see a deep breath before a central event (seen by peak volume increasing rapidly).
We have all seen what CSR breathing looks like, it is a series of 10 breaths with varying degrees of inspiration followed by periods of no breathing followed by series of more breathing. This machine targets all inspiration breaths by looking at the prior 4 minute average. With PB it will stair-step up/down in peak volume. If that inspiration peak line is up it increases IPAP pressure with every breath to meet its target, if that trend is down, it decreases IPAP, this avoids the "deep" breath and overshooting your target peak inspiration. The machine wants to see consistent inspiration breaths, it actually treats every inspiration breath the same. Next thing it looks at is timing between inspiration to inspiration. The closer that is the higher your RR/ BPM will be. All they mean by BPM is the fixed backup mode because that is where you input those settings in.
From my understanding of how this machine works, you leave BPM=Auto until you get EPAP set correctly, get IPAP Min and Max set correctly, then you only change it if you cannot eliminate PB or Central events. Your most fail-safe mode is to keep BPM=Auto. I also believe you should follow basic guidelines established elsewhere and not exceed the 10 cm Pressure Support limit, that limit is to prevent unnecessary lung damage. You don't want to do any harm with the machine.
someday science will catch up to what I'm saying...
