Picking up my BiPAP tomorrow. Wahoo... hopefully!

[xm41907]

I've been on my cpap for nearly a month and it's failed to adequately control my apneas. Last Tuesday, I had a BiPAP titration and the results were "great", at least that's what I was told. I have a pressure range of 8-12, which seems odd considering the CPAP titration said I was controlled at a 6.

Well tomorrow morning I'll be picking up my new BiPAP. It's a PR System One Auto BiPAP (DS750). From what I've read, this is a dual auto/BiPAP. I had the PR System One CPAP, so they're only switching out the actual machine, saving me money says the DME rep. If all goes well, then I'll be paying $49.12 for the next 12 months and it's mine to keep. If all doesn't go well, then it's back to the drawing board for an ASV titration.

I'm just starting to learn more about the autos/BiPAPs, is there anything I should be aware of regarding this machine?

[Pugsy]

I'm just starting to learn more about the autos/BiPAPs, is there anything I should be aware of regarding this machine?

I have the same DS750. You will like it. I have the provider manual. If you want or need it just send me a private message. I am using my machine now in straight bilevel mode with 13 IPAP and 9 EPAP. It's funny but it just feels better while I am awake which really isn't all that important but since I have tried both auto and straight bilevel and both gives me the same results...I use what feels best while awake even if it is for 5 minutes. You will have more different setting choices to choose from inside the clinical settings menu. I left the machine at the default settings except I chose BiFlex of 3 as final exhale relief choice. I like it just a little better than setting of 2. I did the change to BiPap on my own...no history of centrals. Just a fluke thing that I happened to try a BiPap and found that I really, really liked it and I actually felt much better on it for some reason. I don't know why.

Start reading about BiPaps and pressure support and the dance floor...
if you want to understand some of the finer details of how it works. Look for jnk's explanation as to the differences between ResMed and Respironics pressure support.
viewtopic.php?f=1&t=39248&p=376749&hili ... or#p376749

[xm41907]

Fast Forward a week and yesterday I picked up the BiPAP (PR System One Auto BiPAP). I slept fine throughout the night. I did wake up about 4:40 for the bathroom, but otherwise was out from 10:30-6:00. Of course, as soon as I awoke, I pulled up Sleepyhead and sure enough, there wasn't much difference at all. I had two stints of unobstructives, a 30 minute stint shortly after falling asleep, and an hour stint towards the end of the night. I'm fairly certain these periods of unobstructives coincide with REM sleep. This is fairly similar to what I've been having with the CPAP. I typically had 2-3 stints of periodic breathing (looks like Chyenne-Stokes to me) that last 30 minutes to an hour each. Outside of those stints, the unobstructives are onsies and twosies throughout the night. Overall AHI was typically between 25-50.

I was prescribed a setting of 8cm exhale, 12cm inhale, which is fairly higher than what I was on with the CPAP (6cm). I left the machine settings as the DME had them, basic BiPAP set at 8-12. Tonight I plan to switch it over to the auto setting and I'm going to change my settings to 4-12 if possible. I think I read that the System One only allows a difference of 4cm, in that case, I'll go with 4-8 (in playing with the cpap settings, I had lower unobstructives with a lower setting.

I'd appreciate any input on the situation. I didn't have time to copy the report before work or else I'd have attached some graphs. Thanks for your help!

[Pugsy]

In auto mode you can change your pressure support up to 8 if you wish.
While awake though..in Auto mode, until events drive the IPAP up you will only see 2 cm difference if you are watching the pressure on the LCD screen.
Example....if I use my machine in auto mode at my current settings straight bilevel pressures of 9 EPAP and 13 IPAP (I like pressure support of 4) when I first start the machine I will have 9 EPAP and see 11 IPAP. There is a minimum of 2 cm pressure support that is always there until the events start dictating pressure needs. Took me better part of a day to figure out that I couldn't have 4 cm PS while awake...it works as it is supposed to while asleep.

[xm41907]

Thanks for the tip. I sure hope things go better tonight. I'm about ready to throw in the tall regarding the centrals being controlled with the machine. Neither my sleep nor gp doctor has been willing to investigate the underlying cause of the centrals. I'd think that finding the root cause and trying to fix that should be the primary treatment. I guess doctors feel differently. Ugg!

[Pugsy]

Did they do a titration study on BiPap or just give you a BiPap? I can't remember.

Sometimes there is no known cause for centrals. Always good to rule out the usual suspects though.
If I remember right...your centrals weren't huge in number compared to some people. Is it possible that they just aren't frequent enough for the doctor to be concerned?

[xm41907]

I had a titration on the BiPAP. The tech was given the authorization to switch it to ASV if needed, but they didn't. although, according to the summary, I had 0 apnea events for a whopping one hour!. I've lost faith in the ability of a one night study conducted in a clinical setting being able to titrate appropriately. That's why I was so happy to be getting an auto. That way I can evaluate and tweak to get optimum effects.

I wish there was more research regarding central sleep apneas. I totally get the use of an xPAP for obstructives, but for centrals, it just feels like I'm using a crutch and not a treatment. Going strait to an xPAP and not investigating potential neurological causes is not being an affective doctor, IMO.

[Pugsy]

I hear you.

BTW..you might change your equipment to the new machine. Will avoid confusion later.

[xm41907]

After four nights with the BiPAP, I'm convinced it's not working for me either. I continue to have high unobstructives and low obstructives, just as with the CPAP. After the first night, I switched it over to Auto mode and have tried some low pressures and some higher pressures. The lowest Unobstructive number I've gotten is 12 per hour, and with that my hypopnea's increased to about 8 per hour. Also with the higher settings 8 and up, I have higher leaks with my mask, mostly due to opening my mouth (using a nasal pillow). I need to get a chin strap and try that, but I don't think it's going to do anything for my unobstructives.

Here's my thoughts, see if they seem valid.

Throughout the entire use of an xPAP, my unobstructives continue to follow a pattern, clusters of them between 15 mins to one hour, with minor ocassional ones spread throughout. I'd say that it's sleep-stage dependent unobstructives. Both of my titrations demonstrated "success" with 0 apneas for about an hours time. I only have the summaries, so I don't know how the rest of the night went.

I'm planning to contact the doctor on Monday and inform him that the BiPAP isn't controlling them and he's probably going to want to titrate with an ASV. I want there to be concrete proof that an ASV works before getting a prescription, not just a single hour of zero apneas. Is it likely that insurance would pay for a two night titration. First night to determine the best settings, then a second full night at those settings?

Plus, I would like him to attempt to address the underlying cause of the centrals. Up to this point, there has been no discussion about seeing a cardiac or pulmonary specialist to see if something else is going on. I know that the CPAP is working fine for my obstructives, so if the cause could be identified and corrected/minimized, then there would be no need for an ASV, assuming it would work in the first place.

The cause of centrals isn't always identified, but so far, there has been no attempt to identify the cause in my case.

[woodenbuick]

I had large numbers of obstructives and was given the DS 750. They cranked the pressure up to 17/13 and it has stopped them.

I was having one or 2 every minute in my sleep study.

Now my AHI is usually below 2 for the whole night. I do continue to get Centrals though (4 - 8 a night sometimes) and I wonder what that is about.

[xm41907]

My obstructive have always been minimal. It's the central/unobstructives that are my biggest problem. Wouldn't it have been logical to rule out treatable neurological conditions before going on a machine that has questionable effect on centrals?

[teknomom]

I think that central apnea usually happens later in the progress of neurological diseases, not as a first symptom. I also have central sleep apnea and no effort was made to find a cause. In primary or ideopathic central apnea, they don't know the cause. If it really bothers you, be persistent with your doctor. If you can be satisfied with the "nobody knows" approach, just consider yourself one us "lucky" ones. I certainly hope that they give you a chance on an ASV. I have good control of my clear airway apneas, but still have an AHI average of over 5.0 due to hypopneas mostly associated with periodic-type breathing. You can only know what's going on by looking at the data. Good Luck!

[xm41907]

Thanks Teknomom. My AHi continues to run between 25-40. Withe the following rough breakdown, however, it does vary quite a bit.

Hypopnea - Usually 2-10 with a few spikes around 20
Obstructive - Usually 0-3 with a few spikes around 5-6
Clear Airway - Usually 12-25 with several spikes in the 40s and a few lows in the 8-10s.

For the most part, I'm healthy. I've had acid reflux, hypertension, and gout. Other than that, I'm good. At the same time I started on the CPAP, I changed my diet significantly. I did a 7 day juice cleanse, and have been eating about 85% vegetarian. I've eliminated coffee/caffeinated teas, and most junk foods. During that first week (CPAP+ Juice Cleanse), I lost nearly 10 lbs, my blood pressure dropped to normal, and my acid reflux diminished to where I went from a daily pill, to only as needed.

As for the neurological conection to centrals, I'm going to discuss the possibility of seeing a nerologist, pulmologist, cardiologist, to see if they can find any underlying issues that might be causing the centrals. If they can't and I'm designated as ideopathic, then at least I can rule out the possibility of something else.

I've been wondering about the use of supplemental oxygen for my centrals, and also if environmental conditions might be to blame. I sleep in a basement, and I've wondered if there might be a higher concentration of carbon dioxide down here compared to higher levels. Just theorizing, but if I could sleep higher up, then there might be a difference in air quality that could be having an effect.

Lastly, for the most part, I've been feeling great since going on the machine. my blood pressure is better, but that could be a combination of dietary changes and the machine. Who knows if it will drop more if the centrals are under control. My centrals appear to be of the Cheyne-Stokes variety with the pause in breathing being around 10-20 seconds. I'm wondering if things don't work to correct it, if this it's doable to just stay where I am and continue tracking my sleep, hoping whatever is causing the centrals might go away, and then the rest would be controlled.... is that just wishful thinking?

[robysue]

As for the neurological conection to centrals, I'm going to discuss the possibility of seeing a nerologist, pulmologist, cardiologist, to see if they can find any underlying issues that might be causing the centrals. If they can't and I'm designated as ideopathic, then at least I can rule out the possibility of something else.

Coming in late to your story: Did your diagnostic sleep test (the one WITHOUT the CPAP) show any centrals? Or did the centrals appear on the titration test? Or did they appear only after you actually started CPAP therapy?

In other words, I'd like to know whether you are dealing with central sleep apnea (CSA) or complex sleep apnea (CompSA). CSA is diagnosed when there are clinically significant numbers of central apneas present on the diagnostic sleep study. CompSA is diagnosed when significant numbers of central apneas emerge with the initiation of PAP therapy: In other words, for the person diagnosed with CompSA has a diagnostic PSG that shows plenty of obstructive events, but no real problem with central apneas. The diagnosis coming from the PSG is usually just plain old OSA. But once CPAP therapy is started during the titration study, the person starts to have clinically significant numbers of centrals show up even as the pressure brings the obstructive events under control. Or sometimes, what happens is that the titration study can go "OK", but at home the person does not respond to therapy even though they are compliant: In other words even though the person is using the machine all night long, every night, the symptoms that lead to the diagnostic sleep test don't resolve or they get worse. And the data gathered either by the person's CPAP machine or through a second titration study demonstrates that they now have clinically significant numbers of centrals occurring.

I've been wondering about the use of supplemental oxygen for my centrals, and also if environmental conditions might be to blame. I sleep in a basement, and I've wondered if there might be a higher concentration of carbon dioxide down here compared to higher levels. Just theorizing, but if I could sleep higher up, then there might be a difference in air quality that could be having an effect.

It's counterintuitive, but I don't think using supplemental O2 will help with the centrals if they are ideopathic or if they are the result of CompSA.

My understanding is that a central apnea happens when your brain "forgets" to send the signal to breath when you're sleeping---in other words, you are making no effort to inhale for at least 10 seconds. The trigger for "need to breath" during night time breathing is the CO2 level: In other words, when we're breathing normally at night, it is the normal slight rise in CO2 that triggers the breathing response and not a drop in O2 saturation. In CSA and CompSA, somehow this system goes haywire: The higher CO2 level doesn't manage to trigger the breathing response on time. And if I recall correctly, one hypothesis about what might trigger the problem of CompSA is that the PAP machine ends the O2 desats caused by the Obstructive events and hence the overall O2 saturation level returns to normal and stays there all night and that somehow the higher O2 level messes up the brain's ability to make sense of the C02 trigger for breathing. In other words, the CPAP improves the O2 levels and the higher O2 levels lead to the brain losing track of the importance of the C02 level and that leads to the brain forgetting to send the signal to breathe.

My centrals appear to be of the Cheyne-Stokes variety with the pause in breathing being around 10-20 seconds.

Cheyne-Stokes is more than just repeated central apneas. There's a distinctive waxing and waning pattern to breaths themselves: The idea about what happens in Cheyne-Stokes is that the hyperventilation (in the waxing stage) leads to lower than expected CO2 levels, which suppresses the breathing response, and that leads to a series of breaths of decreasing volume, often bottoming out with a central apnea (the brain forgets to breathe), which then allows the CO2 to build up beyond normal levels, which leads to the desire to breath more and more deeply, which then repeats the cycle over and over. This cycle is often referred to as an undershoot/overshoot cycle and JohnBFisher has described it many times, including in this thread where he says:

Central sleep apneas become repetitive due to an unershoot / overshoot repetitive cycle. The undershoot sets up the conditions for the overshoot. The Overshoot sets up the conditions for the undershoot. And so on... During a central sleep apnea there is NO effort to breathe. In the case of complex sleep apnea, the increase in pressure confuses your body. It thinks it does not need to breathe. This is the undershoot side of the cycle. Thus the CO2 builds up until the point that your body must arouse itself to help you breathe better. You restart breathing - hyperventilating a little. That is you breathe faster than normal. This is the overshoot side of the cycle. Now, with the increased respiration, your body blows off too much CO2. This decreases the drive to breathe. Yup. You guessed it. You suddenly slid into the undershoot side of the cycle. You stop breathing for a while and the process repeats over and over and over ...

The System One BiPAP you are using is capable of detecting breathing patterns that have a high probability of being Cheyne-Stokes type breathing. They get flagged as "periodic breathing" episodes. In both Encore Viewer and in Sleepy Head, these periodic breathing episodes are flagged with green backgrounds for the entire breath sequence, with the CA's at the nadir of the cycle being flagged with CA tick marks.

Is your System One's data is actually showing periods of flagged as "periodic breathing" each night? If so, how long do they last? And how much of the night is spent in "periodic breathing"? Because if you are seeing really significant chunks of periodic breathing each and every night, then maybe it is time to consult a cardiologist since CS-breathing can be a symptom of things like congestive heart failure. And if your insurance requires a referral before you can consult a cardiologist, maybe you should bring that idea up with both the sleep doc and your PCP.

[xm41907]

Robysue,

Yes, I was diagnosed with centrals during my initial sleep study. The initial diagnosis was "Moderate Central Sleep Apnea Syndrome" with "Mild Hypoxia".

That first study's numbers were:
88 episodes of apnea/hypopnea
27 hypopnea
2 mixed apnea
49 central apnea
10 obstructive apnea
46 episodes of flow limitation with arousal but not necessarily oxygen desaturations

It did show a higher number of events during REM (33 per hour) than not (20.0 per hour).

Personally, given that there were both centrals and obstructives, as well as mixed, I should have been diagnosed with complex sleep apnea syndrome.

Here is a snippet of one of my clear airway episodes from last night. The entire period lasted 23 minutes with 39 events happening during that time. I had a second period at the end of the night lasting 48 minutes with 77 events. Both were nearly all Clear Airways. I put the total nights Events on top with the area in white the selected. In the Flow rate chart, it does appear to be flagging potential Chyene-Stokes Breathing with the green background. I'm not sure what the two different shades of green represent though.



From what I've read, this looks like classic Cheyne-Stokes to me. What do you think?