Matilda19 Thread - APAP v. ASV treatment questions

[Matilda19]

Hi everyone. I am new here. I have about 1 week to decide whether I am going to buy the same APAP machine I currently have - ResMed Airsense 10 Autoset - or whether I should pursue an ASV prescription. My question for you all is: based on the info provided below, is it likely APAP will work for me long-term, or will I need to upgrade to an ASV machine or another type of machine?

I did my home sleep study on June 14, 2021. I started using my APAP (ResMed Airsense 10 Autoset) on July 29, 2021. I am not able to do in-lab studies of any kind, including titration studies, due to severe chemical allergies. Also, I do not have a doctor at the moment due to insurance issues. I have attached an OSCAR Overview chart & my 2 most recent Daily charts. (I started using OSCAR on August 11 which is why there's less info on the Overview for the dates before that.)

My doctor prescribed APAP of 6.0-16.0 with no EPR which I used for the first 40 days of treatment. As advised by another forum, on September 8, I changed my APAP settings to 8.0-12.0 with full-time EPR of 2. On September 11, I bumped the max up to 12.2.

The details from my June 14, 2021 WatchPAT study are below. Note that my study found 4.7 central events per hour.

Description of Procedures
Unless otherwise noted, respiratory events were scored in accordance with recommended parameters as outlined in the AASM Manual for the Scoring of Sleep and Associated Events, Version 2.6, Chapter IX, Part 2: HSAT Utilizing Peripheral Arterial Tonometry. Unless otherwise specified, pAHI and ODI are calculated using a 3% or greater drop in SpO2 as the definition of a desaturation.

This study was performed using the WatchPat 300. Variables monitored included Peripheral Arterial Tonometry, pulse rate, oxygen saturation, actigraphy, respiratory effort, total sleep time, sleep staging*, body position, and snoring.

Findings
Study was started at 3:19:08 AM and ended at 1:06:24 PM. Total sleep time was 8 hrs, 17 min out of a total recording time of 9 hrs, 47 min, resulting in a sleep efficiency of 84.7%. Indicies are calculated using a technically valid sleep time of 8 hrs, 15 min. REM sleep accounted for 32.7% of total sleep time. The patient slept for 326.5 minutes (65.6 % TST) in the supine position, 169.0 minutes (33.9% TST) in the lateral position, and 2.0 minutes (0.4% TST) in the prone position. Pulse rate averaged 65 bpm, with a minimum of 53 bpm and a maximum of 96 bpm.

WatchPat 300 calculated a pAHI of 28.0 events per hour of sleep, an ODI of 28.0 events per hour of sleep, and a pAHIc of 4.7 events per hour of sleep. The patient experienced a pAHI of 26.8 events per hour of sleep in the supine position, a pAHI of 29.9 events per hour of sleep in the lateral position, and a pAHI of N/A in the prone position. The study also revealed a pAHI of 23.0 events per hour of sleep during NREM sleep, and a pAHI of 38.3 during REM sleep. During the test, the patient spent 1.6 minutes with SpO2 less than 89%, with a SpO2 nadir of 86%.

Scoring utilizing 4% or greater drop in SpO2 as the definition for oxygen desaturation revealed a pAHI (4%) of 24.8 events per hour of sleep and an ODI (4%) of 24.8 events per hour of sleep.

* Sleep staging for the WatchPat 300 is defined as wake; light sleep, deep sleep, and REM. Stages are derived using actigraphy in conjunction with other recorded parameters. Sleep EEG was not recorded.

Glossary
pAHI ‐ is a surrogate for Respiratory Event Index (REI) as well as apnea/hypopnea index (AHI) for the purposes of WatchPat 300 HSAT.
pAHIc ‐ is a surrogate for central apnea index (CAI) for the purposes of WatchPat 300 HSAT
ODI ‐ Oxygen Desaturation Index
ODI (4%) ‐ indicates 4% or greater oxygen desaturation index
pAHI(4%) ‐ indicates AHI was calculated using a 4% or greater desaturation for hypopneas
Technically valid sleep time ‐ total sleep time minus artifact exclusion

Interpretation
Moderate obstructive sleep apnea based on a 4% AHI/REI of 24.8/hour using SpO2 desaturation of 4% to define hypopnea and 3% AHI/REI of 28/hour using SpO2 3% desaturation to define hypopnea. Respiratory events were associated with SpO2 desaturation with a SpO2 nadir of 86%. Time spent with SpO2 < 89%: 1.6 minutes. Frequent snoring was noted. Approximately 66% of time was spent in supine position and 34% in non-supine position (supine AHI 27/hour versus non-supine AHI 30/hour).

Diagnosis (Home Sleep Study): Moderate Obstructive Sleep Apnea – G47.33

I will be very grateful for any feedback you all may be able to provide. Thank you!

[palerider]

As advised by another forum,

What was this "other forum"?

What I'd do is set your *min* to 12 and max to 20, leave EPR at 2, and see how that works for you. (setting the max lower than 20, in most cases, is counterproductive, it just prevents the machine from reacting to any unusual needs you may have on another night).

[Matilda19]

Palerider, thank you for your response and suggestion. The other forum was Apnea Board.

For me it is hard to tolerate pressures above 10 or so; I am often awakened due to discomfort when the pressure is 11-13. Even when my max was set at 16, the max pressure my machine ever got to when I was using it was 13.98. For tonight I might try min 9.0, max 16.0.

Is it dangerous to set the max pressure higher than my doctor recommended? I have had an EKG and it was normal but I do not know if I have other heart issues.

[palerider]

Is it dangerous to set the max pressure higher than my doctor recommended?

Dangerous? no. Many doctors (at least the ones that failed the patients that end up here) know very little about how an auto machine works, they're probably heard the ignorant saying that "a narrow range is better" and so they lower the max pressure setting on the machine, blindly.

[Julie]

You apparently (or your MD?) have it backward - it's the min. setting that does the job, not the max, so setting the max to 20 (as most do) won't affect interference of apneas in the same way the min. pressure (rightly) does, and that setting more often is effective at e.g. 6 or 8 or 10, and rises and falls all night, while the max pretty much stays where it is, so lowering it to e.g. even just 15 can keep the min. from going higher if needed at particular times. Changing the max by e.g. .2 will have no appreciable effect. Got it now?

[Matilda19]

Julie and palerider, thank you for your responses. It seems my doctor was wrong which is unsurprising. She was extremely unhelpful and is not my doctor anymore anyway, due to insurance changing. Then the people at Apnea Board said to set it as min 8, max 12 which made me more confused.

palerider, do you know why people think "a narrow range is better?" I think I have seen a narrow range suggested on Apnea Board and Reddit.

Julie, yes I believe I understand now. Thank you for explaining. Do you think, given my OSCAR info, that it would be wise to try a min of 10 and max of 20 for tonight?

[palerider]

Palerider, thank you for your response and suggestion. The other forum was Apnea Board.

For me it is hard to tolerate pressures above 10 or so; I am often awakened due to discomfort when the pressure is 11-13.

Also, since you ask about ASV, keep in mind that ASVs will induce pressures up to 25 in a single breath, that's their whole purpose, to force you to breathe.

Limiting the MaxIPAP or MaxPS on an ASV defeats it's entire purpose.

[palerider]

palerider, do you know why people think "a narrow range is better?" I think I have seen a narrow range suggested on Apnea Board and Reddit.

I don't know why, any more than I know why some people think the moon landing was faked, that the earth is flat, that vaccines don't work, etc. (ok, my theory is "ignorance".)

Julie, yes I believe I understand now. Thank you for explaining. Do you think, given my OSCAR info, that it would be wise to try a min of 10 and max of 20 for tonight?

To further expand on Julie's answer, think of the max as being like the speed limit on the road you're on. If you're driving a motor scooter, or a golf cart, it doesn't matter if the speed limit is 70, 85, or 200mph, your scooter/golf cart won't ever get up to the speed limit. the "Max" setting on an apap is like that speed limit.

However if you've got a speedy car, and the speed limit is 40, and there's a cop around every corner to spike your tires and write you a huge ticket... you're not going over 40, even if you really want (or, for reasons unknown NEED) to go faster.

Question, when you say it's "hard to tolerate" pressures over 10, is that because you wake up when the pressure is higher, or because you wake up with severe stomach pain?

If it's just 'waking up', then it might be the breathing events that are causing the pressures to go up that are waking you (because, after all, that's what they do) and then you see the pressure and think "damn pressure woke me up again"?

[Matilda19]

palerider, thank you for both of your comments! All of this makes sense. I appreciate the road speed limit metaphor & also your comment about ignorance.

For "hard to tolerate" what I meant is I wake up--no stomach pain--and I thought the reason I was waking up was the increased pressure causing my mask to sort of flap against my face / leak air (I have the F30i mask). However, you are right that the breathing events themselves could be the cause. Very good point.

The reason I was worried about a max pressure of 20 being dangerous is I have read that before getting an ASV you are supposed to get tested to make sure your heart is working well. I think I read ASVs can cause heart attacks in some patients from the sudden, high pressures. But clearly the source could be wrong or I could be wrong, as I am just beginning to learn everything.

[Julie]

Hi, you can try, but why not just go to 9 for 1-2 nights and see how that goes. Thing is also to only try one change at a time so you're sure when you feel better (or worse) which variable is responsible....remember that what happens on any given night may never occur again - why we do things, or why the machine does, is often a one-off mystery, so repetition can be a give-away when you become more sure of anything.

[Matilda19]

Thank you, Julie. That makes sense.

Do you (and palerider) think it'd be better to first:
a) keep minimum the same (at 8 ) and move the maximum up (to 20)
or
b) move minimum up to 9 and keep maximum the same (12)
or
c) something else?

[Matilda19]

Also, I am gathering it will likely take some time to try various settings with the APAP before I would know if I need to upgrade to ASV. Is that true?

If so, what are all the things I would need to try with APAP before I could "rule it out" as a machine that will work for me?

For example, would I need to make sure I have tried APAP with a maximum pressure of 20 & maximum EPR (3)? Would I need to try different types of masks? Et cetera

I very much appreciate your help.

[Pugsy]

The reason I was worried about a max pressure of 20 being dangerous is I have read that before getting an ASV you are supposed to get tested to make sure your heart is working well. I think I read ASVs can cause heart attacks in some patients from the sudden, high pressures. But clearly the source could be wrong or I could be wrong, as I am just beginning to learn everything.

No...ASV don't cause heart attacks from the higher pressures used.
What the potential risk was and all the hoopla was a study done some years ago (not the best study it was later determined) where there seemed to be a slightly higher mortality rate among some very sick ASV users and by very sick I mean they had known congestive heart issues and fairly significant CHF problems.
Crappy study really.....they took people with bad CHF problems who had central sleep apnea and who admitted to not even using the machine all night long....and ended up blaming the machine when those very sick people died but they really never could say why the machine was to blame. Those people were walking time bombs as it was.

Anyway as long as the cardiac ejection rate is above 45% it was determined okay for people with known congestive heart failure to use ASV.

At this point I don't see where you need ASV. I would suggest following PR's ideas and deal with the obstructive stuff first and THEN see how many centrals you might be having.
It is entirely normal to have a few centrals anyway. We all have a few from time to time...me, PR, Julie...everyone.
Deal with what you can deal with using this machine and then see what's left.

[chunkyfrog]

Sounds like the study was financed by some knife-happy surgery group . . .

[Matilda19]

Pugsy - Thank you very much for your response. I really appreciate the additional info about the ASV study. I will try out PR's ideas.

Do you all think it would be wise for me to buy my own APAP (Airsense 10 Autoset) at this time? The reason I'm in a bit of a decision-making crunch is that since September 1 I am now on a new & terrible insurance plan, with $0 paid toward the $1,450 deductible. So it would likely be more expensive, in the long run, to continue renting my APAP through the DME than to just buy one out of pocket. I have until September 26 to return the APAP to the DME without being charged an additional month's rent for it. Starting September 27, the rent amount will likely be between $100 and $250 a month because it will all go toward my deductible (the DME didn't know the exact price). There is an online DME I could get a brand new Airsense 10 Autoset from for $975 that could be here within a week. But I didn't want to buy an APAP if you think it is likely I will need an ASV soon.