Rapid Breathing-Fractured Sleep-Out of Breath

[SingleH]

In addition to the above, here is a screenshot from a relatively bad night. You can see there are many of these recoveries, some taking place when his insp time is flatlined and others when it is within range. His Timax at this time was 2.1 reduced down from 3.0.

I have looked back to compare when he had a long inspiration time and they seem to be present then, so if reducing Timax is reducing CO2, its not affecting these recoveries. What I can see is when I had a lower PS applied of 5.0 vs around 7.6 to 7.8 the breathing waveform during the recovery events is far worse and the moments preceding the event you can see the waveform basically degrades to nothing with a lot of very shallow breaths before hand. Whether that is just a symptom rather than a cause, I dont know, but I suspect just a symptom as his waveform is generally always worse with a lower PS anyway.

I have been having an ongoing issue with his spont cycle being low due to having to cut his Timax short, he needed a really long timax of 3.5 to get a half decent spont cycle figure, however I read that flow limits can be a cause of the need to take long breaths. I have a theory that by keeping his timax short to cap the CO2 issue and then keep increasing his EPAP and PS high, his flow limits will be are reduced, I expect to see his insp time start to fall in line, stop flatlining and reduce in duration and spont cycle go up. I will see if this combination has any effect on these events.
Going back through data I can see that these recoveries occur in either scenarios of Low EPAP and high PS or High EPAP and low PS. I am now trying High EPAP and high PS.

           

[Sleeprider]

The more important metric here is not the spontaneous cycle, but the resulting tidal volume. He simply does not need more inspiration time to maintain an impressive Vt and good Vm of 8.0 L/min. He is adequately ventilated and a longer TiMax was already found to infringe on adequate expiration time. There does not appear to be any further issues with stacking here, and I think you have narrowed down the optimal range of Ti for him. Too much and he will use it and become unbalanced. I don't see any issues with evaluating some higher PS give the residual flow limits at PS 5.0, but I would take it slowly and methodically. The best indicator of flow limitation is excessive inspiration time, and higher PS may shorten that, but I think you still have to impose the TiMax as a limiter as he seems to stay in inspiration, even after a complete breath, e.g. a reluctant spontaneous cycle.

[Fixit50]

What Sleeprider says makes sense here.  I think the idea is to get oxygen in a relaxed and balanced manner.  So good tidal volumes and minute vent and reasonably balanced breathing, probably translate to success.  When I had my chaotic and rapid breathing patterns, tidal volumes (Vt) were very low for a protracted period of time preceding the recovery.  Minute Vent was good but I believe that is deceptive because with very low tidal volumes, I’m re-breathing a higher percentage of used air (CO2).  This combination led to large recoveries and arousals, probably due to CO2 buildup.  I’ve read somewhere that strained, flow limited breathing, results in CO2 buildup.  In your post above showing the recovery at 5:47, Vt is very low preceding the recovery.  The breathing looks to be flow limited which of course explains the low Vt although I’m surprise that flow limits are not showing up preceding the recovery, so I don’t get that part.  The recovery at 3:30 is similar.  Vt there is also reduced preceding the recovery though maybe not as bad.
The thing that perplexes me I mentioned a little earlier.  I occasionally I see recoveries in my data when breathing really doesn’t look bad preceding the recovery.  That tends to cast doubt on the premise here.  One such example follows.  The breathing preceding the recovery is a bit jagged here, but the Vt looks to be only mildly reduced from the median of 620 for the night.  It seems to be meandering around 450 to 550 which I would think is okay, but maybe not. 

As you can tell, there are unanswered questions remaining…
   

PS: Sleeprider, what do you mean in your post #62 by "..further issues with stacking.." I don't know what stacking means.

[SingleH]

Hi Fixit50, if you search for "breath stacking" you fill find a lot of info this is all to do with CO2 and the timing settings whereby you are taking more breaths without sufficient time to exhale the CO2.

Based on your comments I went back through the data and you are right in that there are times when these recoveries happen yet there are no flow limits, however I was able to find many occasions when the recovery was preceeded by a flow limit and generally in most occasions there was a significant flow limit preceeding the recovery. On doing a quick check, I would say there are probably more recoveries where a flow limit is present than not, but there are still quite a few where no flow limit is present. You can see in the first image the machine scaled up the pressure in response to the flow limit.

I think this recovery issue may be due to insufficient pressure support and/or EPAP. I adjusted my dads machine last weekend so he has been running on a higher min EPAP since last weekend, when I get to check the data next I will see where the increased EPAP has had an affect, I already know it has reduced his events as he has told me. If they are still ocurring I will increase PS and see what happens.

Ive attached a few more screenshots for your reference.


           

Can you post some graphs pinning the blue mask pressure graph and flow limit. I dont think we need to observe Tidal Volume and Minute vent anymore as they universally behave the same each time.

[Fixit50]

Hi Fixit50, if you search for "breath stacking" you fill find a lot of info this is all to do with CO2 and the timing settings whereby you are taking more breaths without sufficient time to exhale the CO2.
Thanks for pointing this out.  I do need to get a better understanding of the causes of CO2 buildup and how to best deal with it.

Based on your comments I went back through the data and you are right in that there are times when these recoveries happen yet there are no flow limits, however I was able to find many occasions when the recovery was preceeded by a flow limit and generally in most occasions there was a significant flow limit preceeding the recovery. On doing a quick check, I would say there are probably more recoveries where a flow limit is present than not, but there are still quite a few where no flow limit is present. You can see in the first image the machine scaled up the pressure in response to the flow limit.  Its interesting to note that your dad's data shows this same character.  I  would estimate 75% or more recoveries are preceded by significant flow limits and marked decrease in VT, but as I noted, there are exceptions.  Its instructive to note you are seeing the same thing. 

I think this recovery issue may be due to insufficient pressure support and/or EPAP. I adjusted my dads machine last weekend so he has been running on a higher min EPAP since last weekend, when I get to check the data next I will see where the increased EPAP has had an affect, I already know it has reduced his events as he has told me. If they are still ocurring I will increase PS and see what happens.

Ive attached a few more screenshots for your reference.

Can you post some graphs pinning the blue mask pressure graph and flow limit. I dont think we need to observe Tidal Volume and Minute vent anymore as they universally behave the same each time.  Yes, I'll try to do this maybe a little later today.  

[Fixit50]

Here's some screen snips showing recoveries in various settings with mask pressure and Flow Limits visible.
           

[Fixit50]

A few more examples.  These show flow limits preceding the recovery...
           

[SingleH]

So from the screenshots it looks like you experience these events in situations both with and without flow limits.

In a number of screenhots it also looks like after your recovery you assume expiratory mouth breathing waveform, or at least thats what it looks like to me. Do you have other periods of doing that in general.

Does that continue on afterwards, or does your breathing return to a normal waveform







Ive attached a screenshot below which shows expiratory mouth breathing


   


Here is another screehshot from the same period, and you can that during the long period of expiratory mouth breathing, the pressure graph is totally flat and remains on the minimum EPAP, flow limits are also zero. He has these periods almost every other night and on 100% of these occasions there is zero flow limits, very few events and the machine makes no changes. You can see below at around 07:22 he changes to normal breathing and almost immediately the machine detects flow limits, then increases pressure and a recovery occurs.

I'm trying to wrap my head around what is going on, I know very little about expiratory mouth breathing, but Im assuming that means inhaltion is still through the nose. If absolutely no events occur when inhaling through the nose and exhaling through the mouth, then does that mean the flow limit is occuring due to the mouth being shut and causing some kind of resistance, perhaps due to poor tongue posture or being pushed back into the throat. I'm wondering if these recoveries are a "failed apnea" or an apnea in the making that does fully develop.


   


Are you experiencing this breathing waveform at all, if so it would be useful to post screenshots with both the mask pressure, and the regular pressure graph as the regular graph shows pressure changes a bit more clearly.
Do you see a difference in the number of recoveries that occur when you sleep with and without your chinstrap, this would be useful as it might confirm whether the jaw position is playing a part in this.
Finally a curveball quetion. Have you had any orthodontic work done on your jaw, tooth extractions, dental crowding, braces as a chilld or adult?

[Fixit50]

So from the screenshots it looks like you experience these events in situations both with and without flow limits.

In a number of screenhots it also looks like after your recovery you assume expiratory mouth breathing waveform, or at least thats what it looks like to me. Do you have other periods of doing that in general.
Yes.  I’m pretty sure my mouth drops back and I do some mouth breathing probably after I’ve been asleep for a while.  The first snip below is an example of what looks like expiratory mouth breathing to me.  The second pic is zoomed out on the same night where the period from 2am to 4am captures expiratory mouth breathing. 

Does that continue on afterwards, or does your breathing return to a normal waveform 
In the example recoveries I posted, it returned to more normal soon after the recovery. Are there implications or consequences to expiratory mouth breathing? 

Ive attached a screenshot below which shows expiratory mouth breathing

Here is another screehshot from the same period, and you can that during the long period of expiratory mouth breathing, the pressure graph is totally flat and remains on the minimum EPAP, flow limits are also zero. He has these periods almost every other night and on 100% of these occasions there is zero flow limits, very few events and the machine makes no changes. You can see below at around 07:22 he changes to normal breathing and almost immediately the machine detects flow limits, then increases pressure and a recovery occurs.

I'm trying to wrap my head around what is going on, I know very little about expiratory mouth breathing, but Im assuming that means inhaltion is still through the nose. If absolutely no events occur when inhaling through the nose and exhaling through the mouth, then does that mean the flow limit is occuring due to the mouth being shut and causing some kind of resistance, perhaps due to poor tongue posture or being pushed back into the throat.  In my case, I have lower flow limits and fewer events when my mouth is kept closed.  If I wear a mouth guard or chin strap to keep my mouth closed, I get fewer events, lower pressures and lower flow limits.   I'm wondering if these recoveries are a "failed apnea" or an apnea in the making that does fully develop.

Are you experiencing this breathing waveform at all, if so it would be useful to post screenshots with both the mask pressure, and the regular pressure graph as the regular graph shows pressure changes a bit more clearly.
I do see this at times and it comes and goes.  I haven’t really kept an eye on it until now, so I can’t speak to any patterns. 
Do you see a difference in the number of recoveries that occur when you sleep with and without your chinstrap, this would be useful as it might confirm whether the jaw position is playing a part in this.
I certainly don’t see more of them with the chin strap and probably see fewer of them although they are present even with the chin strap.  Normally the magnitude of the recovery is lower when I’m wearing the chinstrap.  The recoveries with no chin strap and while using the AutoSet cpap often woke me up short of breath, something that has not happened while wearing the chin strap or when on the VAuto even without the chinstrap.
Finally a curveball quetion. Have you had any orthodontic work done on your jaw, tooth extractions, dental crowding, braces as a chilld or adult?
Braces as an adolescent, no extractions, two caps.  

       

[SingleH]

I dont know if there is any implication of expiratory mouth breathing, not been able to find anything on that as yet, although I do know that cpap aside, mouth breathing does have some health implications, as air should pass through the nose which in turn stimulates the production of nitric coxide which in turn has cardiovascular benefits. Orthodontic work such as extractions can result in smaller dental arches and less space for the tongue to "sit" resulting in it being pushed back and reducing the airway and in turn people compensating by breathing through their mouth. Not an issue in your case.

I see in your screenshot there are three very small flow limits that occur around the time of the recoveries, although there also appears to be one where there is no flow limit occuring.

I cant draw any further conclusion at this point, other than my " failed apnea in the making" theory. When I next get to check my dads stats I will see if the combination of higher EPAP and higher PS had any effect on these recoveries.