Transition from DreamStation 2 to AirSense 10

[Crimson Nape]

First, do you feel any better, the same, or worse? Your Hypopneas and CAs seem to be positional, otherwise they would spread out through the night.

An AHI value is just a guide post. The length of an event is very important. Consider these 2 scenarios, you have 2 nights where you slept for 8 hours each. One night had 4 events and the other had 8 events. The 4-event night displayed a .5 AHI, but each event was 30–45 seconds in length. The 8-event night had a reported AHI of 1, but each event was 10–12 seconds in length. Which one would be of a greater concern? This brings up my next question. What do the times of your events look like? To easily see these, look at the Events tab on the left and expand the CA events. The hypopneas do not have a time value on a Resmed. In this case, you might need to use a 2 or 3 minute zoom of your Flow Rate and try to guess their length.

Finally, we could always increase your EPR from 1 to 2, but will need to raise the current pressure up by 1 to account for this. Increasing the EPR may decrease your flow limits, but may increase your CAs due to CO₂ washout. (no biggie).

What are your thoughts?
- Red

[prince01]

I didn't think it was a particularly restful night of sleep and recall feeling like I was "fighting" the machine's pressure on exhalation.  That may be, in part, due to having gotten used to the ramp as an aid to falling asleep.

I completely understand your point on how the AHI is a helpful metric but not necessarily the end all/be all.  Ultimately, it's about sleep quality/health.  Related to your question on length of events, if I'm interpreting OSCAR correctly, all the CAs were between 11 and 16 seconds - those are the numbers in parentheses.  Looking closely at flow rate, the hypopneas also seem quite short - most looking like only a few seconds long.

Your comment about the events being positional is interesting.  I have felt for some time that my current mask is somewhat disruptive because of the position of the tubing connection.  Is it possible that fighting the tubing as I move throughout the night is occasionally forcing me into a  position that is exacerbating the events?  While I consider myself a side sleeper, I do sometimes find myself on my back.  Related, I just received a new mask today with the tubing connection at the top of the head - decided to try this in an attempt to reduce tubing wrangling disruptions - and hopefully positional problems.

One other question - since OAs are all but absent with the AS10, is it possible pressure is now simply too high and partly to blame for the CAs?  When I was using the DS2, median pressure was typically around 9.  Now, with the AS10 using the same settings as the DS2, median pressure is ~11.5.  I have heard (and do believe) these two brands/CPAPs manage pressure very differently with the AS10 having a much more aggressive algorithim.

Thoughts about next steps?

[Gideon]

Differences between Philips and ResMed

• Algorithms, ResMed is more aggressive, as a rule that means that your pressure (auto mode) can be quite a bit lower on a ResMed.  Don't be afraid to lower the pressure
  
• Flow Limits drive pressure up on a ResMed. ResMed uses Flow Limits as a predictor of potential apneas and raises pressure to head off future events
  
• Pressure Relief, Philips pressure relief is more of a true comfort feature, it is dynamic, not fixed, and varies based on several factors including how aggressive you are breathing.  On the other hand ResMed's EPR is fixed pressure which makes ResMed VERY effective as a mini BiLevel.  It is limited to 1, 2 or 3 cmw difference between inhale and exhale.  This difference is extremely effective in managing hypopneas, flow limits, and RERAS and UARS which are fundamentally flow limitations.  With Philips to accomplish any of this you need to significantly increase pressure.
  

The big issue you are having now is with flow limitations.  I also think you will do fine with a lower pressure. so

Min Pressure = 7 (allows the full use of EPR) 
EPR= 3, Fulltime
Ramp: Off (Note: Events occur, but are not reported during the ramp.

This change utilizes the strength of the ERP algorithm which actually is indistinguishable on the charts between an AutoSet and a VAuto BiLevel set to deliver the same therapy.

[prince01]

Gideon,

Thanks for providing your experience and advice.

Based on your guidance, I set pressure range to auto with a range of 7-12, EPR to 3, left the ramp off.  Last night was also my first night using the ResMed AirFit P30i Pillows Mask.

Excellent results as summarized in the attached screenshot.  All events remained quite short.  Feeling pretty well rested this morning and also felt the sleep was relatively comfortable.

Thinking of leaving settings alone for a few nights and collecting a bit more data before changing anything else.  That said, I may be able to further reduce maximum pressure even a bit more.

Thoughts?

[Gideon]

Your max pressure doesn't matter unless your comfort dictates otherwise. Your Max pressure would be less than 8 without the flow limits which are what is causing the vast bulk of your pressure increases.
Use these for a while, change nothing. Then try a soft cervical collar. I'd like to see how that works for you. To be clear, this is completely optional. The hope is that that will reduce your flow limitations and improve comfort. BUT with your stated comfort NOTHING needs to be done.

[prince01]

Thanks Gideon.  I'll maintain the status quo for the next few day before doing anything else.  Maybe nothing else will be needed to provide consistent positive results.  After a few day, I'll consider whether to try the collar.

[prince01]

Gideon,

Same settings for the last 12 nights - pressure 7-12, EPR 3.  Only change was switching from medium to large pillows on my mask to reduce leaks.

Overall good results albeit somewhat variable.  Last 3 nights sceenshots attached.

Average AHI over those 12 nights was 2.0 (0.9 CA, 0.4 OA, 0.7 H).

Thinking about reducing maximum pressure and/or EPR to fine tune therapy.  Thoughts?