Newbie - Help with AirCurve

[Sleeprider]

Your leaks are much better controlled, but that is a pretty amazing AHI. If you are using a collar and your chin is not escaping under the front edge, it's possible you're going to need to change therapy strategy if the CA events are real. It will help to get a few screenshots of the flow rate at about 3-minute duration so we can clearly see the nature of these events by looking at the wave form.

[Gideon]

What I think happened is that you had an episode of chin tucking, the resulting obstructions caused recovery breaths that lowered your CO2 levels to below your apneic threshold. The CAs are a cycle of events increasing and decreasing around your apneic threshold resulting in the clusters of central apneas as your body is trying to stabilize.

If you are using a collar your chin is tucking behind the collar, if not you need one.
Let's look at some 3-5 minute segments of the central clusters to see if this theory holds up.

[Apple83]

Thank you both for your help. I have been wearing the collar - I think it prevents the chin tucking but I could be wrong. 

Here are a few zoomed in snapshots of the last two nights

   
   
   

[Sleeprider]

The scale on the flow rate is too high from -180 to +180 and we are losing resolution. You should change scale to about half that to -80 to +80. That can be done by right clicking on the Y-axis near the Flow-Rate label and override the Y-Axis scale. You can also add a dotted line at zero flow which will show inspiration/expiration crossover. Right now it looks like expiration is missing, as though you are perhaps exhaling orally. The leak rate during these events is just short of a large leak, so I suspect you are inhaling nasally and exhaling outside the mask. This could be affecting the number of events as the machine fails to pick up breaths. The morphology of the apnea does not appear characteristic for either central or obstructive, and perhaps the change in scale will help.

[Apple83]

I've changed the Y-axis for these charts below. 

I do use a full face mask and tend to breath through my mouth as I have significant nasal congestion at the best of times. 

Thanks very much for your help

   
   

[Sleeprider]

The first problem is that your average breath rate is only 9.8 per minute, which means a breath cycle every 6.1 seconds. A slight delay in your normal breath rate results in a pause of 10 seconds which flags the apnea. Your respiration is chaotic in timing during these clusters, and it's impossible to tell what is an apnea and what is just a longer pause in respiration. Depending on the quality of your insurance, I can only suggest that you either bring this results to your doctor's attention and request a titration test, or that you simply self-fund appropriate therapy. Given your young age, normal weight and health, and history of CA events, I think you need ASV. You can buy a lightly used Resmed S9 VPAP Adapt (ASV) for about $500, or a used Aircurve 10 ASV for about $1350. If your insurance is good, you are already through CPAP and bilevel, and only nee to ask for titration for bilevel and ASV to find an effective treatment. You need ASV. How you get there is the only question.

[Apple83]

Thank you sleep rider!

Yes I have a very slow resp rate naturally - I believe that I have periodic breathing throughout the day. I personally think these CAs are just my normal breathing pattern that I've been doing since I was a kid. I'm not sure that they are in fact a problem? The pulsing that the machine does every few seconds I find very annoying though..

I've actually felt a lot better since starting CPAP - do you think that cleaning up the CAs with an ASV machine will make that much of a difference? I wonder about just increasing the pressure to get rid of the OAs and then leaving the CAs.

I'll keep my eyes out for a good deal on an ASV machine as I think the process to get it covered through insurance will take at least a year here in Canada.

[Sleeprider]

If the problem is really a slow and erratic respiration rate, ASV is not the answer. The most simple CPAP or bilevel that does not do the pulsing to determine type of apnea will give you the therapy you want, but very little data. We can't turn off the apnea detection of the Vauto, so I would need to do some research to find machines that do not probe for airway condition, but I think the Aircurve 10 ST is one that reports UA (unidentified apnea) instead of CA and OA. It does not use the FOT pulse. to determine the type. The ST is a fixed bilevel machine that has a timed backup to trigger IPAP, which actually might work pretty well for you to remind you to breathe. The timing can be set to 7 BPM which means it would not trigger IPAP unless you paused breathing just than 10 seconds. Of course it also triggers with spontaneous breathing as well. Not my favorite machine for most cases, but could work for you.

[Apple83]

Thanks sleep rider. The AirCuve VAuto you actually can turn off the FOT pulse if you set it to 'S' mode and you turn easy breathe off. That is part of the reason I bought this machine was to try and see if that would help. I found that solution on another thread on this forum. When I did that my AHI was 22.

I think I may end up trying to get the ASV as it seems that this is the ultimate solution. Will see how long it will take to get it under insurance first.

[Sleeprider]

Without a backup rate, a bilevel machine will wait for you to spontaneously trigger IPAP. The Resmed ASV is particularly good at maintaining your natural respiration rate and kicking in as much pressure as might be needed to trigger a breath. I agree that might be your best option. Other machine algorithms are often based on manual BPM settings and provide timed breaths. You want more than 8 BPM to avoid apnea flags.