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Hi, introduction and my experiences [Recommendation on settings?]
#1
Hi, introduction and my experiences [Recommendation on settings?]
Hello,

I started to put together the following post with links to imgur but received the message that I need 8 posts before I can do so? Can someone help me out here? I'd like help interpreting my data.

I'm new to the forum but have already benefited greatly by the support offered here. Thank you.

I'm using a Resmed Aircurve 10 ASV in auto mode.
MIN EPAP 04
MAX EPAP 15
MIN PS 04
MAX PS 15
RAMP 5

Can someone explain to me what is happening here with these apneas and hypopneas? Is the machine responding to the events, or is the increased pressure of the machine actually causing the reduction in respiration?

Would you recommend any changes to help reduce these events?

So far the machine seems to be working well, and I am sleeping reasonably well now.

I would also appreciate tips on staying on my side. The best luck I had was with a backpack stuffed with towels and a basketball, but it was not very comfortable.
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#2
RE: [split] Hi, introduction and my experiences
G'day 12344321, welcome to Apnea Board. I've split your post out into a thread of its own so it will get individual attention.

Due to the number of spammers around, we've had to institute a policy that new members can't post clickable links. It's a pain, but unfortunately necessary. In the meantime you can attach a screen dump of your report. You can find the instructions here: http://www.apneaboard.com/forums/Thread-How-to-HOW-DO-I Select the first option insert an attachment (for CPAP stuff only).

Your machine settings are "wide open" and you will very likely benefit from some fine tuning, but we need to see the actual data first. Can you post a screen dump from SleepyHead?
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#3
RE: [split] Hi, introduction and my experiences
Thank you DeepBreathing.

I fiddled with optimization for a while, but the best I can do to get the file size down leaves me with one screen shot. This does show a fairly typical pattern.

Please comment! [attachment=2307]

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#4
RE: [split] Hi, introduction and my experiences
Courier,

The short answer to "what is happening here with these apneas and hypopneas?" is that your machine is preventing the vast majority of them from happening in the first place: Your overnight AHI = 0.58 and it looks like you had a grand total of 5 events in about 8.5 hours of usage. (Reality check: 5/8.5 = 5.88 and you actually used the machine a bit more than 8.5 hours.)

With respect to the particular apnea you zoomed in on, the long answer is: You are running in ASV mode and when the machine detected that no air was going into/out of your lungs for a sufficient amount of time, it looks like the machine rather drastically increased your IPAP pressure in an attempt to "trigger" an inhalation---that's exactly what an ASV machine is supposed to do by the way. To confirm that's what the machine is doing, it would be very useful to look at the mask pressure graph along with the flow rate graph and the pressure graph in the same zoomed in scale as the attached image.

It also appears that the machine was unable to successfully trigger an inhalation in this particular instance. That probably means that the apnea was an obstructive apnea instead of a central apnea. (ASV machines are designed to treat central apneas by triggering inhalations.)

In an obstructive apnea, the airway has physically collapsed. So none of the added air from the increase in pressure could get through to the lungs to "trigger" an inhalation. That would result in the flat flow rate graph during the duration of an obstructive apnea. At the end of the apnea in question there is a very classic example of a "recovery breath" which also points to a high likely hood of this being a isolated OA---i.e. you aroused enough to open up the collapsed airway and took a big sudden inhalation to get the O2 level back up to snuff. As soon as the machine detected the recovery breath and the return of normal sleep breathing, it decreased the pressure back down to your baseline pressures as the ASV algorithm tells it to do: You are breathing on your own so there is no longer any need to try to trigger inhalations.

It's important to understand that your machine will not prevent every single event from happening. The point of PAP therapy is to prevent the vast majority of events from happening. Your machine prevented all but 5 events from happening during the entire night. That's excellent. In general, therapy is considered effective when the treated AHI is less than 5 night after night after night ...

A few more comments about things you've written:

(03-26-2016, 02:19 PM)12344321 Wrote: [font=Courier]I'm using a Resmed Aircurve 10 ASV in auto mode.
MIN EPAP 04
MAX EPAP 15
MIN PS 04
MAX PS 15
RAMP 5

Why were you put on an ASV in auto mode in the first place? Was your diagnosis central sleep apnea? Or were you diagnosed with obstructive sleep apnea, but then put on an ASV after/during your titration test showed a problem with central apneas when using CPAP?

What was your diagnostic AHI? And what was the break down between OAI, CAI, and HI?


Quote:Would you recommend any changes to help reduce these events?

Your data is EXCELLENT. There is NO reason to change your pressure settings based on this particular night's data, particularly when you go on to say:
Quote:So far the machine seems to be working well, and I am sleeping reasonably well now.



Quote:I would also appreciate tips on staying on my side. The best luck I had was with a backpack stuffed with towels and a basketball, but it was not very comfortable.

If your PAP settings are optimized, there is no need to try to stay on your side when sleeping: The pressure from the machine should be sufficient to prevent most of your events from happening even when you are sleeping on your back.

And it looks to me like your PAP settings are indeed optimized. So my advice is to not worry about trying to stay on your side as long as your data looks good and you are sleeping reasonably well.


Questions about SleepyHead?  
See my Guide to SleepyHead
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#5
RE: [split] Hi, introduction and my experiences
robysue,

I was diagnosed with idiopathic nocturnal seizures in late 2014. There is research literature that details that alleviating sleep apnea can improve seizure control. After my husband observed changes to my breathing, including what appeared to be obstruction/hypopneas followed by cessation of breathing (central), then seizure, I consulted a sleep physician, completed a home sleep study and started pap therapy. Because there were both obstructions and central apneas, I started on ASV auto mode. I am waiting to see at the end of June another sleep specialist for a second opinion and in lab titration but need to do what I can to help myself in the meantime.

I experience two types of seizures while sleeping - partial and generalized. This means that in one type I wake up with altered consciousness and inability to talk, and in another I have the classic grand mal seizure. The pap therapy has basically eliminated the partial seizures, going from as many as 15 per night to none or 1. I have not been on treatment long enough to evaluate the generals, which occur much less frequently. Seizures increase with any kind of congestion or exposure to allergens, again pointing to obstructive component.

With the machine I believed that I was free to sleep on my back, but that night, even with the machine, I experienced some partials and an increased AHI, so we returned to my husband rolling me over whenever he found me on my back.

While I understand that my numbers may look decent, due to the detrimental effects of seizures, I would like to do everything possible to eliminate events, with as much fine tuning as can be done. This is why I am trying to understand the data and determine if there is anything I can do to get to zero events, to eliminate obstructions ( I am trying to learn of all possible solutions in addition to pap) and to breathe as regularly as possible.

There seems to be a theme on this board that it may take time to adjust to pap therapy, so I am hoping that things will only improve over time.

ran-man has a short post on nocturnal seizures and SA but unfortunately not much detail there.

I am posting the data again with mask pressure. I will have to delete the other attachment due to my space limitations.

Thanks for any additional insights.


Attached Files
.pdf   SH MP file opt.pdf (Size: 144.28 KB / Downloads: 58)
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#6
RE: [split] Hi, introduction and my experiences
(03-28-2016, 05:27 PM)12344321 Wrote: I was diagnosed with idiopathic nocturnal seizures in late 2014. There is research literature that details that alleviating sleep apnea can improve seizure control.

...

I experience two types of seizures while sleeping - partial and generalized. This means that in one type I wake up with altered consciousness and inability to talk, and in another I have the classic grand mal seizure. The pap therapy has basically eliminated the partial seizures, going from as many as 15 per night to none or 1. I have not been on treatment long enough to evaluate the generals, which occur much less frequently. Seizures increase with any kind of congestion or exposure to allergens, again pointing to obstructive component.

Given the history of seizures, you are dealing with a very non-standard form of sleep problems and that undoubtedly has some potentially serious implications on the treatment of your condition.

In other words, you are going to need to work with your doc(s) far more than a person with run-of-the-mill OSA does. And you are also going to need to take every piece of advice on how to tweak your pressure settings with a HUGE grain of salt. In my own opinion, I think you should NOT be adjusting any of the therapy settings on your machine until you and your docs have a better understanding of how well the ASV is handling the seizures, and you have a really good understanding of exactly how the ASV algorithm works and how each setting affects how the ASV algorithm works.


Quote:With the machine I believed that I was free to sleep on my back, but that night, even with the machine, I experienced some partials and an increased AHI, so we returned to my husband rolling me over whenever he found me on my back.

Given the non-routine background of your sleep disordered breathing condition, I think you should report this to your doctor. He may suggest increasing the min EPAP a bit. But personally I would NOT increase the min EPAP without a doctor's ok if I were you.


Quote:While I understand that my numbers may look decent, due to the detrimental effects of seizures, I would like to do everything possible to eliminate events, with as much fine tuning as can be done.

I know that you would like to eliminate every single event. But that may not be possible. It is really rare for a PAPer to have an AHI = 0.0 day after day after day. Your AHI for the data you posted was well under 1.0. That is darn near perfect from a statistical point of view, and there may not be any tweaking that will consistently get your AHI even lower.

A question: Did you have any seizures on the night for which you posted the data? If so, can you correlate the seizures with anything in the ASV data for the night? In particular, did you happen to have a seizure right around the time of the apnea that you zoomed in on?


Quote:This is why I am trying to understand the data and determine if there is anything I can do to get to zero events, to eliminate obstructions ( I am trying to learn of all possible solutions in addition to pap) and to breathe as regularly as possible.

Understanding the data has to come first. Until you fully understand all aspects of your data, you really are not in a position to start trying to tweak things on your own. On an ASV with a nonstandard form of sleep disordered breathing it is possible to make things worse with a seemingly small change in one or more of the therapy settings. That's another reason that I would strongly encourage you to work closely with your doctors in trying to tweak your settings.



Quote:There seems to be a theme on this board that it may take time to adjust to pap therapy, so I am hoping that things will only improve over time.

Yes, it can take a while to fully adjust to pap therapy. For people with ordinary old OSA it can take anywhere from a week or so (if you are lucky) to a month or so (if you're kind of typical) to as long as 6-12 months or more (if you are very unlucky.)

But anything that is non-standard can also affect how long it takes to really adjust. A lot of that has to do with how quickly a good therapeutic setting can be found that deals with the non-standard problem.

Here is a marked-up version of the same data that you posted.

[Image: Mu7hbIY.png]

Notice that I've put a big Red box around the apnea.

To understand what I'm trying to call attention to you need to understand the meaning of the mask pressure graph: The highest points on the peaks of the mask pressure graph are at the current IPAP setting for the breath. The low troughs in the mask pressure graph are at the current EPAP setting for the breath.

In the mask pressure graph you can see exactly what the ASV algorithm is doing during the apnea: When your breathing stops for a sufficiently long time, the machine starts cycling between EPAP and IPAP even though it is not detecting any inhalations in the flow rate graph. And notice that the the top peaks of the mask pressure graph increase in size as the machine continues to detect no air going into your lungs. That represents the machine jacking up the IPAP pressure really suddenly and pretty significantly over just a handful of "triggered breaths". In other words, in an effort to get you to inhale, the machine increases the IPAP from what looks to be about 10cm before the apnea starts to about 17-18cm on the two "largest" trigger-breaths.

The smaller trigger-breath in between the two really large ones is most likely in response to a small amount of air going into your lungs. (See the dotted blue line going up to the flow rate curve). The last really large trigger-breath corresponds to when you do start breathing again. And notice that just as soon as you are breathing normally again, the IPAP drops back down to about 10cm. That's because the machine is now following your breathing and increasing the pressure to IPAP when it detects the start of your inhalations. The ASV only increases the IPAP drastically when it is trying to trigger an inhalation---i.e. it uses the increased IPAP to act like a ventilator.

Now a really good question is whether this apnea is really an obstructive apnea. My guess is that it probably is: I'm pretty sure that if the airway were clear, the increase in IPAP ought to show up as at least a small bump in the flow rate. But that's just my guess as a knowledgeable patient. You really need a sleep tech or a sleep doc to look at that to be sure.

Finally you will notice that SH has the apnea labeled as a Unclassified Apnea (UA). Many ASV machines do not attempt to determine whether the airway is obstructed or clear when an apnea is detected. Rather the ASV algorithm kicks in on all apneas because the whole point of using an ASV is to prevent a long string of central apneas from occurring.

Strings of CAs typically start with a CO2 overshoot/undershoot cycle: The first CA is the result of "blowing off" too much CO2, and that suppresses the breathing drive. And so the breathing slows down (and the CO2 starts to build up) and an CA occurs. That's the undershoot part of the cycle. After the CA occurs, there's a tendency to hyperventilate, which again blows off too much CO2 and the cycle starts over. The way an ASV treats these strings of CAs is that it prevents the undershoot in the first CA from happening by the "triggered breaths". It forces enough air into the lungs to keep you ventilated and that allows for the proper exchange of CO2 to happen. So even if one CA actually happens, the triggered breaths prevent a whole string of them from happening.

It's also worth noting that the ASV algorithm can kick in if the size of the inhalations is not large enough to keep you properly ventilated and your CO2 levels in check.

Questions about SleepyHead?  
See my Guide to SleepyHead
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#7
RE: [split] Hi, introduction and my experiences
RobySue,

That is all very helpful information. Thank you. I will post more data tomorrow.

Can you explain to me the relationship between flow rate and respiration rate data? You say that a flat flow rate curve represents cease of breath. Why does the respiration rate stay constant during a good portion of time in which the flow rate goes flat?

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#8
RE: [split] Hi, introduction and my experiences
(03-29-2016, 10:09 PM)12344321 Wrote: Can you explain to me the relationship between flow rate and respiration rate data? You say that a flat flow rate curve represents cease of breath. Why does the respiration rate stay constant during a good portion of time in which the flow rate goes flat?
Respiratory Rate measures the number of breaths over a fixed amount of time. I'll be honest, I'm not sure what the time frame is, but it basically is counting the number of breaths over an interval that is more like 20-40 seconds rather than the 3-5 seconds that usually occur between the beginning of consecutive inhalations.

To make this clearer, let's make some rather bald-faced, but useful assumptions that will simplify the calculations quite a bit. Let's suppose first that the CPAP uses a one-minute moving window to compute the RR. So the value in the RR graph represents the number of breaths that you have taken in the last minute. Let's also suppose (for sake of simplicity) that your inhalations are spaced at 4 second intervals when you are breathing normally. In one minute you will have taken 15 breaths, so the RR = 15 when you are breathing normally.

Now lets suppose that an apnea happens and the apnea is 17 seconds long. What's going to happen to the RR graph during and after that 15 second long pause in breathing?

Well, first we have to realize that you only miss a total of 3 breaths during the 17 seconds you are not breathing. Let's look at what happens to the RR graph as you miss each of those breaths and also what happens once normal breathing resumes.

5 seconds into the apnea you have missed the first expected inhalation. So in the last 60 seconds, you've only inhaled 14 times instead of the normal 15. So the RR graph drops from 15 to 14 approximately 5 seconds into the apnea.

10 seconds into the apnea you have missed another expected inhalation. So in the last 60 seconds, you've only inhaled 13 times instead of the normal 15. So the RR graph drops from the current value of 14 to 13.

15 seconds into the apnea you have missed a third inhalation. So in the last 60 seconds, you've only inhaled 12 times instead of the normal 15. So the RR graph drops from the current value of 13 to 12.

The apnea ends a few seconds later so you don't miss any additional breaths. But next 60 seconds those missed breaths still affect the RR rate:

20 seconds after the apnea started, you've still missed 3 breaths in the last minute, so the RR rate is still 12 instead of your normal 15.

40 seconds after the apnea started, you've still missed 3 breaths in the last minute, so the RR rate is still 12 instead of your normal 15

At roughly 65 seconds after the apnea stared, that first missed breath is no longer inside the 60 second window used to compute the RR. Hence at roughly 65 seconds after the apnea started, you've only missed 2 breaths in the last 60 seconds. So the RR goes up from 12 to 13.

At roughly 70 seconds after the apnea started, that second missed breath is no longer inside the 60 second window used to compute the RR. Hence at roughly 70 seconds after the apnea started, you've only missed 1 breath in the last 60 seconds. So the RR goes up from 13 to 14.

At roughly 75 seconds after the apnea started, that third missed breath is no longer inside the 60 second window used to compute the RR, and so roughly 75 seconds after the start of the apnea (and roughly 60 seconds after the end of the apnea) your RR is finally back up to your normal RR = 15.

The net result of this is that you see a small lag in the RR graph that starts after the first breath or two has been missed during the apnea. And the RR will remain lower than normal for a while after the apnea has ended because each of the "missed breaths" has to move out of the moving window used to compute the RR before the RR goes back up.
Questions about SleepyHead?  
See my Guide to SleepyHead
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#9
RE: [split] Hi, introduction and my experiences
RobySue,

Great explanation. Basically, AVERAGE miles per gallon rather than INSTANTANEOUS miles per gallon. I'm glad you explained, because I inaccurately assumed that RR was instantaneous, which I might not have had I really looked at the data. I'm going to review some previous data now with this new thinking in mind.

I do remember reading that the AHI graph is also collective over time.


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#10
RE: Hi, introduction and my experiences [Recommendation on settings?]
Here are two nights data.

On Monday, around 5:20am (I didn't exactly note the time, which would have been greatly helpful), there was a very mild siezure, more like an aura, which is just a sense that one is approaching.

Tuesday. No difficulties.

I'm wondering if you see anything interesting in this data. Does it look typical for what you have seen with your or other sleep data?

Monday

http://imgur.com/a/pocHN



Tuesday
http://imgur.com/a/F9Ilq


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