New to CPAP, just used OSCAR for the first time, should I be concerned?(Cheyne Stoke)

[breckenk]

Last night was rough. Do you think I should go back to the original settings then? I'll check out the positional apnea wiki page.

   

[Sleeprider]

The purpose was to see if reducing EPR to zero would relieve central sleep apnea. It does not, so feel free to restore EPR and go back to the more comfortable setting. You appear to have CPAP therapy induced central apnea, and if this continues, you will fail CPAP and will require evaluation for ASV. There are no additional settings we can suggest to help with this problem, and you may want to notify your doctor's office that you are experiencing higher AHI than your test baseline, and all apnea are central. You should discuss the continued use of this therapy in light that it actually makes your AHI worse than no therapy. We don't see that very often.

[breckenk]

Went back to the original settings, and ordered the Caldera Releaf neck rest to try to combat the positional breathing, to no avail.

   
   

My doctor wants to see me back ASAP, so will likely have an appointment sometime over the next week. Until then, I have to keep using the machine at least 4 hours a night for insurance.

Also, thank you for your help with this, Sleeprider!

[Sleeprider]

My recommendation is to cease use of the CPAP. Your AHI is lower without it. You may find the soft cervical collar is actually more helpful without therapy to stop obstructive apnea, but it is kind of pointless to continue using a therapy that creates a bigger problem than before you used it. ASV will be the solution to this and will result in near-zero AHI. Do not accept ST as a substitute. I am linking to a reference that has the Resmed Clinical Titration Protocol for all types of positive pressure machines. It will be useful to educate yourself on the titration process and how different machines work. https://document.resmed.com/en-us/docume...er_eng.pdf

[breckenk]

I will cease use of the CPAP as soon as I can, but I was told by my doctor to continue until I see him next. What is "ST"? I will definitely make sure that ASV is the next step. I also have an echocardiogram on the 21st to confirm there's no underlying heart issue, so I think the next steps will be cessation of the CPAP once I see my doctor, nothing except perhaps the brace until I get the confirmation from cardiology, then ASV.

[Sleeprider]

The reference I sent explains what all the different types of CPAP and bilevel machines are. ST stands for "spontaneous-timed". We have to cover some basics here. All bilevel machine have two pressure channels, inhale (IPAP) pressure is the higher pressure delivered during inspiration and exhale (EPAP) is the lower pressure delivered during exhale. The difference between IPAP and EPAP is pressure support (PS). Technically CPAP does not have a separate inhale/exhale pressure channel, but Resmed pushes the envelope with EPR which is bilevel with a limited PS of 3. PS can do many things. As pressure increases during inhale, the PS makes inspiration easier. It further expands an open airway and reduces or eliminate flow limitations or upper airway resistance. Pressure support can assist inspiration enough to overcome hypopnea and even central apnea.

Bilevel machines come in two basic flavors. Spontaneous triggered machines rely on the user's spontaneous respiratory effort to trigger IPAP and cycle to EPAP. Spontaneous bilevels include the VPAP S, Vauto and ST in spontaneous or "S" mode. Bilevel machine with a backup rate use an algorithm to trigger IPAP if the patient fails to spontaneously breathe. In the case of the ASV (adaptive servo ventilator), the algorithm tracks and targets the previous 90 seconds of respiration rate and minute vent volume and uses pressure support to ensure the respiration rate and volume is maintained with or without spontaneous effort. When hypopnea or central apnea occur, the ASV delivers pressure support as needed to normalize a breath that would otherwise be missed or inadequate. The ASV is for individuals like you with mixed or central apnea and periodic breathing, but that are otherwise free of pulmonary diseases. The ST is a more primitive machine that works spontaneously to trigger, or can provide timed breaths to meet a target rate. For example if a target rate of 12 breaths per minute is set, the machine will trigger IPAP every 5 seconds. It is a "dumb" machine, but it works for people with respiratory insufficiency, but unfortunately many doctors prescribe the ST for individuals with CA. Note that the Clinical Titration Guide says ST is intended to treat COPD, neuromuscular diseases, obesity hypoventilation syndrome and other respiratory conditions. That doesn't sound much like you, and that is why I want you to educate yourself on this before meeting the doctor.

[breckenk]

I had an appointment with my sleep doctor today. The next step will be to get a proper in-house sleep study to confirm the central apneas are occurring without the CPAP, and then the solution will be an ASV. No mention of ST. He is having me continue the CPAP for now to see if it's treatment induced central apneas that go away over time. He estimates a few weeks until I can do the in-house sleep study as they're very heavily booked. Unless something very out of the ordinary occurs, this will probably be my last update until the sleep study. I can't thank you enough for your assistance with this.

[Sleeprider]

It's good your doctor acknowledged the actual condition. It leaves unanswered what will happen if central apnea is not present without CPAP, but is a therapy induced condition, but he seems to at least acknowledge CA is a possible and knows how to to treat it. I have become a cynic from being on this site so long and helping many others with similar issues. There are many doctors that will dismiss a patient that presents complex issues.

[breckenk]

Finally ready for an update. After two in-hospital sleep studies (The first confirmed central apneas but couldn't confirm ASV settings because I couldn't fall back asleep once it started, they required me to sleep on my back which I cant do for very long), I finally got my ASV yesterday and used it for the first time last night. Uploading the results. At this point it seems like it's just about fine tuning everything. Uploading first night results here. Is this leak rate concerning, or anything else you notice? I know I have a long ramp period, I find it tough to fall asleep with the thing fully applied, I figure this will get better over time and I can adjust.

[Sleeprider]

You got almost default settings on the ASV for your money, and that would be what I expect.  Your current settings are ASVauto, EPAP min 4.0, EPAP max 15.0, PS min 3.0 and PS max 15.0 Ramp on 45 minutes.  I'm going to start by suggesting settings even closer to Resmed's recommended default but that consider your first chart results:  ASVauto, EPAP min 5.0, EPAP max 8.0, PS min 2.0, PS max 11.0, Ramp OFF.  

The use of ramp is a complete mystery, especially for someone already accustomed to PAP therapy. There is no treatment during ramp, and to use the 45 minute setting makes your machine effective with a constant pressure of 4.0...ridiculous.  EPAP min of 5.0 should be more comfortable and is approximately your current median. PS min of 2.0 is normally more comfortable and again reflects your median PS min however I don't expect any issues and normally suggest PS min of 3.0 to nearly everyone.  PS max reflects your actual maximum PS in therapy was approximately 8.0, so you don't need 15 cm.  I don't expect significant improvements in therapy other than you will at least get some in Ramp which is an especially important time as many individuals experience sleep transition centrals.  For reference, here is Resmed's titration protocol for ASV and ASV auto, which will show my suggested modifications are consistent with these.