Does BiPAP have unintended side-effects?

[heelbruise]

I somewhat remember reading a blog a while ago from a health professional claiming that BiPAP should not be used unless there is a really good reason. The logic was something along the lines of: having a different pressure for the inhale and exhale can cause an imbalance in the intake of O2 and the expiration of CO2 (in normal Sleep Apnea patients). The BiPAP should be used when the patient already has a condition where there is an imbalance of O2 and CO2 flow and the BiPAP machine can counter that imbalance.

However, I can't find anything about it anymore. I didn't pay attention much, because I wasn't using BiPAP at the time.

Now, I have set the EPR level to 3 (max) on my ResMed Autoset 10 (essentially creating a BiPAP machine as I understand). I'm waking up feeling terrible in the morning and I have frequent awakenings during the night. I'm trying to attack this from all angles and I think it's worth considering if BiPAP is contributing to my symptoms. 

I started using BiPAP because I switched to Nasal Pillows (Bleep DreamPort) and I found it difficult to get used to. During exhale, I had the sensation of not being able to fully exhale. It was uncomfortable. Max EPR resolved that completely.

I am going to be experimenting with lowering the EPR or only keeping EPR on the ramp. 

Side question: is there a way to change the start pressure on the ramp? I'd like it to start at 7 or 8 instead of 5.

If it matters: My pressure range = 9.5 - 16.5 and typically stays between 9.5 and 11

[Sleeprider]

Individuals tolerate bilevel pressure differently, and if there is an increase in CA events with more pressure support, that suggests that the additional ventilation may be reducing CO2 to near the apneic threshold. There are many reasons for recommending bilevel pressure, ranging from increased comfort, particularly with higher pressures, to treating flow limitation and hypopnea and other more advanced respiratory therapy. Your recollection has little resemblance to my understanding of bilevel application.

The EPR with your Airsense 10 is a limited bilevel experience with up to 3-cm of pressure support. Your therapy range provides from 9.5/6.5 to 16.5/16.5 bilevel pressure. That is quite a trick since the Airsense 10 can only be set to even pressure in multiples of 0.2, so 9.4 to 16.4 seems more likely. There are many good reasons for using EPR, and I have no acquaintance with your results or goals prior to using EPR or even why you're experiencing sleep disruption now. Posting charts would be a good start. As far as changing EPR to ramp only, I think that is misguided and shows you don't really understand the use and application of these settings. EPR apparently resolved your discomfort with pressure using nasal pillows. If you want some insights based on your needs, post some charts. Instructions for organizing and attaching charts are included in the links in my signature.

[SarcasticDave94]

Your take about what docs think on BPAP is half right, heelbruise. They can cause that imbalance in some and that's why these lazy docs would rather take the easy way out and stay with CPAP for all. It's harder for them to do something to support you than it is to issue CPAPs like Pez. The patients that need a BPAP do have to balance out the various pressure settings. Some are susceptible to CA events from pressure swings, and that adds time to get the machine set right. Time some docs aren't willing to give to help get it right. And there is the insurance aspect docs have to be aware of. The doc and insurance clash if they issue BPAPs supposedly too freely. No matter what, the patient is stuck in the middle during the equipment struggle.

[heelbruise]

I believe you're right about me being misguided. Can you share with me what you know? Should I be using EPR? Is there any concern for it? Can it make you feel worse if you aren't using it correctly or aren't supposed to be using it at all? And how can I answer these questions for myself?

I attached my graphs following the very awesome instructions in your signature. You will also notice some leakage. I don't know what else to do about it. I tape my mouth shut. The air just leaks into my stomach and mouth. Drying my mouth and giving me painful gas. I will take all the info you got!

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Your take about what docs think on BPAP is half right, heelbruise. They can cause that imbalance in some and that's why these lazy docs would rather take the easy way out and stay with CPAP for all. It's harder for them to do something to support you than it is to issue CPAPs like Pez. The patients that need a BPAP do have to balance out the various pressure settings. Some are susceptible to CA events from pressure swings, and that adds time to get the machine set right. Time some docs aren't willing to give to help get it right. And there is the insurance aspect docs have to be aware of. The doc and insurance clash if they issue BPAPs supposedly too freely. No matter what, the patient is stuck in the middle during the equipment struggle.

That's disheartening to hear. Do you have tips on how I can treat myself? Or do I need some in-lab titration study or something?

[SarcasticDave94]

I'd have thought BPAP should have been better and more comfortable since you're running pressures over 15. The biggest thing on the chart I see is that higher leak rate. If you're taping already, you may have to consider a full face mask if you can't get mouth leaks under control. As for air swallowing, you may need to reduce max pressure a bit until you're better able to handle the higher pressure. That's one area the BPAP could be better for you.

[Sleeprider]

Interesting, and by the numbers, your results are very good here. The main issues are leaks and a fairly low tidal volume and minute vent, but inspiration/expiration times are as expected, and there is certainly no indication of a carbon dioxide imbalance. I think EPR in this chart s reducint flow limitation, and keeping pressure from being more variable than what would be present without it. Do you have a chart of what your therapy looked like before using EPR?

I want to clarify that while I don't agree with some of the ideas in the frst post regarding bilevel or EPR, the comfort of therapy and sense of well-being that comes from that, regardless of settings is far more important.

[heelbruise]

Interesting, and by the numbers, your results are very good here.  The main issues are leaks and a fairly low tidal volume and minute vent, but inspiration/expiration times are as expected, and there is certainly no indication of a carbon dioxide imbalance.  I think EPR in this chart s reducint flow limitation, and keeping pressure from being more variable than what would be present without it.  Do you have a chart of what your therapy looked like before using EPR?  

I want to clarify that while I don't agree with some of the ideas in the frst post regarding bilevel or EPR, the comfort of therapy and sense of well-being that comes from that, regardless of settings is far more important.

This is very informative. Really, thank you. I have a followup question. I have terrible chronic nasal congestion (which I suspect could be the cause of my sleep apnea). I also wake up in the night often, as mentioned. Specifically, I wake up most during the late morning which is where the majority of REM sleep happens. As we know, REM sleep contains the highest rate of apneas due to the paralytic aspect of REM sleep. Each time I wake, I wake with an increasingly larger headache. I wake for the final time feeling exhausted and with a bad headache. 

When my nasal congestion is better, these symptoms are better. But, you know it's hard to assume causation.

Now I know you mentioned low tidal volume and minute vent. Could there be some relation here? I don't know, maybe my nasal congestion is making it difficult for CPAP to be effective? Perhaps low tidal volume and minute vent are signals to that? Perhaps the machine isn't quite catching all the events due to potential UARS? I really don't know what I'm talking about here, so could you offer some insight into some of these thoughts?

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I'd have thought BPAP should have been better and more comfortable since you're running pressures over 15. The biggest thing on the chart I see is that higher leak rate. If you're taping already, you may have to consider a full face mask if you can't get mouth leaks under control. As for air swallowing, you may need to reduce max pressure a bit until you're better able to handle the higher pressure. That's one area the BPAP could be better for you.

I see. Yeah I was using full face but the compression of the straps was killing me after a few months. That's why I switched to Bleep Dreamport. My pressure typically never rises above 11. It's a tough trade-off because I need this pressure to treat my sleep apnea. 



Do you think it's possible I need a proper BiPAP machine with a wider delta between inhale and exhale pressure?

[Sleeprider]

Heelbruise, we are looking at your therapy from the mile-high level. If you want to zoom in on the flow rate at about a 2-minute resolution, we will be able to see the shape of the respiratory wave. It will either reveal a nice normal rounded wave-form or more likely, a flattened , flow-limited one. I suspect we will see that at 02:00 on your last chart. If the latter is the case, then pressure support is a solution for that, and may improve volume. For nasal congestion, especially related to allergy, don't overlook trying fluticasone propionate (Flonase). I want to keep the problem of mouth leaks front and center as a priority to reduce sleep disruption and improve therapy.

[heelbruise]

Heelbruise, we are looking at your therapy from the mile-high level.  If you want to zoom in on the flow rate at about a 2-minute resolution, we will be able to see the shape of the respiratory wave.  It will either reveal a nice normal rounded wave-form or more likely, a flattened , flow-limited one.  I suspect we will see that at 02:00 on your last chart.  If the latter is the case, then pressure support is a solution for that, and may improve volume.  For nasal congestion, especially related to allergy, don't overlook trying fluticasone propionate (Flonase). I want to keep the problem of mouth leaks front and center as a priority to reduce sleep disruption and improve therapy.

I've attached a new image. Is this more helpful? I do see a flattened section here. How did you suspect that there would be something at 2:00? There are no labeled events here, which is odd. Is it because the pressure starts to rise? And why exactly does it rise so much here when there are no labeled events?

What is "pressure support"?

Yeah, Flonase is pretty good for about a week or two. Then I develop a tolerance. I've even had surgery which barely helped. Believe it or not, I sleep outside now which kinda helps more.

[Gideon]

Pressure Support is simply the difference between Exhale and Inhale pressures.

There is a continuum of Obstructive events from apnea to hypopnea to flow limitations to normal. ResMed uses flow limitations as a precursor to apnea and hypopneas and as such raises pressure to head off apnea and hypopneas. The flow limits chart indicates the flatness of the flow rate chart which indicates flow limitations.