xaid - Therapy Thread

[Sleeprider]

C-Flex and A-Flex are pressure transition algorithms used by Philips to improve comfort in its CPAP units. It is not comparable to Resmed EPR. This wiki covers the Philips pressure relief algorithms. https://www.apneaboard.com/wiki/index.php?title=C-Flex C-Flex causes a reduction of pressure at the beginning of expiration and returns to the set CPAP pressure before expiration is complete. A-Flex provides pressure relief at the beginning of expiration and reduces pressure up to 2-cm by the end of expiration, and rounds out the pressure changes to make them less abrupt. Resmed EPR is indistinguishable from the pressure support of the Resmed Aircurve bilevels and provides up to 3-cm of pressure relief which can be seen in a mask pressure graph that Philips does not produce. https://www.apneaboard.com/wiki/index.ph...lief_(EPR)

There are a lot more differences between the two manufacturer algorithms. Philips auto pressure algorithms are much slower to respond to flow limitation, and events than Resmed, and it returns to minimum pressure faster. Pressure increases are fastest when snoring is present. The variable breathing algorithm essentially cancels the Auto CPAP pressure algorithm. https://www.apneaboard.com/wiki/index.ph..._Breathing
https://www.apneaboard.com/wiki/index.ph...Algorithms

This all gets too complex. Most people are more comfortable and get fewer events on a Resmed machine. In your case, A-Flex has the best shot of helping, but we have not documented a predictable response of flow limits in Philips machines because it is simply not tracked by the machine in a useful way.

[xaid]

Thank you, @Sleeprider, for the good explanation and advice. I feel that I have a better understanding of therapy optimization, thanks to your efforts.

I have changed the setting to (Min: 10.50, Max: 14.50, A-Flex: 3).
I had longer and more rested sleep (not optimal, but better than the last few weeks). I guess I need more nights to compensate for the sleep debt. Right?

I attach my sleep charts from the last night with the new settings. The flow limitation is lower, but still high (according to this table).

Are there any recommendations regarding the number of nights/hours to judge the optimization step results? I mean, when shall I decide whether to keep the setting or try something else?

I will try to increase the min pressure to 11 or 11.5 to see if things become better. Thought?

[Sleeprider]

Your event rate is improved, and the flow limits look less severe. Not much is quantifiable in the statistics, but I can ignore most of that in exchange for an improvement in comfort and sleep quality. That is a move in the right direction. The expectation of immediate recovery and relief may be unrealistic, but is common among new users. Improvement is usually gradual, and sometimes inconsistent. As you make changes to your settings, it may help to keep a log of how your feel so that if you go over the ideal target you can get back to what worked.

[xaid]

I am using DREAMWEAR silicone nasal pillow mask and wondering about the benefit of the slit on the front of the mask (see attachment).

It emits air that makes the bed partner uncomfortable and sometimes it makes noise at high pressure. Does it affect the therapy if I tape close it? Will the device readings be affected and require adjustments while viewing the charts?

   

[YipeekiOH]

If I were you I would consider the ResMed P30i. It has a “quiet vent” and will not disturb your bed partner. I use the Dreamwear nasal cushion mask and it too shoot out a lot of air. What I would not do is block anything on a mask as CO2 needs to escape on exhale.

[Nightynite]

As stated above those holes are for carbon dioxide venting .

[xaid]

I have been using Phillips Respironics Dreamstation since Sep 2022.
My therapy maintains low AHI (<3) but I feel tired and exhausted after waking up. I guess it is because of the flow limitation (between 0 and 1.7 but in most nights higher than 0.2) and RERA (reaches up to 1.33 on some nights). I attached one night charts which may help.

I looked at Flow Limitation Statistics and RERA and have some questions for the experienced members.

1) How do RERA and FL relate?
2) What is the acceptable RERA number before optimizing therapy, if any?
3) How do FL and RERA affect sleep if the oxygen level is maintained high? Higher than 92% and mostly between 95% and 98% (sing O2 Ring).
4) I am thinking of shifting to Resend Airesence 10. Do Airsense 10 report RERA and FL? or I will be looking for them eyeballing the charts?
5) Finally, are there any indicators other than AHI, FL, and RERA to look at to improve sleep quality?

[gainerfull]

RERAs are a flow limitation in the upper airway that is not significant enough to be classified as a hypopnea and are identified by waxing & waning of breathing. It looks like your pressure range is pretty tight and typically RERAs are solved with more minimum pressure. Have you considered 11cmH20-15cmH20 to give your CPAP more room to solve these events or is there a reason your range is so small?

[Melman]

To answer question #4; the Resmed airsense10 autoset reports RERA and flow limitations.

[xaid]

Thanks, for everyone who is helping us in this forum. My life is totally changed when I started calibrating my therapy using the advice of the experienced members on this forum.

I am using DreamStation for the last 17 months. Although my AHI is very low, I do not get a comfort sleep. I have been  advised by other forum members that AirSense's algorithm is better for the therapy comfort. Since CPAP device is not covered under my insurance and we do not have the luxury of returning devices if we do not like, I wanted to make good decision before committing to such investment.


I have two questions here.
1) For whoever with experience with Airsense 10 and 11, what are the advantages of Airsense 11 over 10. Does it worth the difference in price?
2) When migrating from Dreamstation to Airsense are there any recommendations on settings to start with? i.e. do I use the same pressure I used to with DreamStation? Or I must start over with trial and error until I get the convenient settings?