aerophagia

[jerry1967]

What does Tidal volume mean and is the number important? Mine is an average of 600 with 95% of 820 and Max is 1060.

[Sleeprider]

I expect that your hypopnea is related to exceeding your apneic threshold as pressure rises. If that theory is correct, limiting maximum pressure should reduce your AHI.

[jerry1967]

I expect that your hypopnea is related to exceeding your apneic threshold as pressure rises. If that theory is correct, limiting maximum pressure should reduce your AHI.

Any chance you can explain apneic threshold in layman's terms so I can understand what it is?

I have my upper high limit set at 17, are you saying I should lower that number? Very rarely does it ever get that high. I  would say about 1 night out of 14.

[Sleeprider]

What drives the need to breathe? Carbon dioxide is the answer. If you intentionally hyperventilate you will not only increase your blood oxygen level, but will reduce CO2. This allows you to hold your breath until CO2 levels rise and the need to breathe becomes overwhelming. The apneic threshold is the point at which CO2 (pCO2) in the blood drops to where the respiratory drive is satisfied and you pause breathing. Instead of hyperventilating, suppose CPAP or especially bilevel pressure is sufficient to reduce CO2 below the apneic threshold. You will probably pause breathing, or breathe more shallow, especially during sleep. Breathing cessation causes apnea, and breathing shallow can be hypopnea. We see respiratory volume oscillate in some people using PAP therapy and that oscillation can be very slight, or very pronounced with central apnea at the low point. In very severe cases, we can use ASV to stabilize respiratory volume, but for most people, we just keep the pressure or pressure support below the level where CO2 is excessively expired, while maintaining airway patency to prevent obstruction.

I am simply suggesting that you reduce the maximum pressure to reflect your 95% pressure on an average night.

[jerry1967]

What drives the need to breathe?  Carbon dioxide is the answer.  If you intentionally hyperventilate you will not only increase your blood oxygen level, but will reduce CO2. This allows you to hold your breath until CO2 levels rise and the need to breathe becomes overwhelming.  The apneic threshold is the point at which CO2 (pCO2) in the blood drops to where the respiratory drive is satisfied and you pause breathing.  Instead of hyperventilating, suppose CPAP  or especially bilevel pressure is sufficient to reduce CO2 below the apneic threshold.  You will probably pause breathing, or breathe more shallow, especially during sleep.  Breathing cessation causes apnea, and breathing shallow can be hypopnea.  We see respiratory volume oscillate in some people using PAP therapy and that oscillation can be very slight,  or very pronounced with central apnea at the low point. In very severe cases, we can use ASV to stabilize respiratory volume, but for most people, we just keep the pressure or pressure support below the level where CO2 is excessively expired, while maintaining airway patency to prevent obstruction.

I am simply suggesting that you reduce the maximum pressure to reflect your 95% pressure on an average night.

Ok, will try. I have also lowered my EPR TO 3. Since I have done that my numbers are lower. Both central and hypopnea but I worry about C02. Is this a needless worry?

[jerry1967]

When I started on CPAP therapy. I had a problem with aerophagia (swallowing air). I tried antacids, simethicone to break up bubbles, different masks, sleeping positions, and playing around with pressure settings to balance my discomfort with an acceptable AHI and leak rate. None of this produced an acceptable result.

After much experimentation, what seemed to work for me was to use ResMed's EPR (expiratory pressure relief.) feature to reduce exhalation pressure. It appears that by not fighting against exhalation and swallowing air because of the effort, the issue resolved itself. My current settings are 12-15.6 with an EPR = 3. My AHI is sub-1 (normally 0.4 - 0.7) with a 14.6 (95%) pressure.

I do not know if this is a one-off that works only for me, but you might try it.

I will try this but I was told it would increase my Centrals. right now mine EPR is one so I will try 2 for a while and see how that works out. Thank you for your time.

I am trying 3 AHI  now. the first two nights my number was below 5 which is good for me. I will keep trying it.  I also get Cheyne stokes respiration sometimes. When I get this Cheyne Stokes seems like I have a bad leak.

[Sleeprider]

I'm unsure of your question about CO2, but it is something your body naturally regulates. When CO2 rises in the blood stream, you will naturally breath deeper and faster. If CO2 becomes low, such as after you hyperventilate, or blow up a balloon, you will breathe more shallow and slower. You do not have Cheyne-Stokes Respiration (CSR), you have occasional periodic breathing with a rhythmic oscillation in respiratory volume. A higher leak rate can flush expired CO2 from your mask and tube which may be affecting your respiration rate. We sometimes use Enhanced Expiratory Rebreathing Systems (EERS) to help individuals with therapy onset CA to intentionally increase the rebreathing of exhaled air and to stabilize CO2 at a higher level.

[jerry1967]

I'm unsure of your question about CO2, but it is something your body naturally regulates.  When CO2 rises in the blood stream, you will naturally breath deeper and faster.  If CO2 becomes low, such as after you hyperventilate, or blow up a balloon, you will breathe more shallow and slower.   You do not have Cheyne-Stokes Respiration (CSR), you have occasional  periodic breathing with a rhythmic oscillation in respiratory volume.  A higher leak rate can flush expired CO2 from your mask and tube which may be affecting your respiration rate.  We sometimes use Enhanced Expiratory Rebreathing Systems (EERS) to help individuals with therapy onset CA to intentionally increase the rebreathing of exhaled air and to stabilize CO2 at a  higher level.

I am just going by what the machine says about Cheyne-Stokes Respiration. The machine gives me Cheyne-Stokes on some nights. Is there a way to tell if the machine is misreading my breathing?

[Sleeprider]

Resmed made a mistake when it used the CSR label to report this. It was, and remains irresponsible to use a diagnostic term for a variation in breathing volume that is not CSR in most cases.  Compare to this image below and tell me your breathing even remotely resembles CSR.  I would prefer that OSCAR reports events flagged as CSR by Resmed as Periodic Breathing, but the development team has decided to stick with the manufacturer label. Philips calls your event Periodic Breathing  (PB), Resmed calls it Cheyne Stokes Respiration CSR, and I'm telling you, that is an error. Post a chart, and we can verify.

[jerry1967]

I download the new version of OSCAR and when I use it I get a different AHI than the one from my machine. Like this morning OSCAR said my AHI was 4.3 but my machine gave me an 8.8. Can anybody tell me why I am getting a different number?

Still working on loading a copy of my report to see about my Cheyne Stokes.

OSCAR recording time is one hour late for some reason. If I turn the machine on at 12 midnight OSCAR doesn't start until 1:00 a.m.