gas

[Guest]

Ok, I have about 600 hrs on my machine. I am starting to suffer from build up of air in my stomach when in use. Is there some way to not swallow air or is this a "have to live with" situation? I must say it is bothersome to say the least. For me and the rest of the family.......

[coffee overachiever]

thats my post, didnt know I wasnt logged in. I think this intake of air is effecting my quality of sleep.

[GuyK]

I recently talked with my somnodoc about aerophagia (the buildup of gas during *PAP therapy). We also discussed reflux (I've had reflux issues in the past, but those symptoms have disappeared since I started therapy).

What I took away from him is that my reflux issues and aerophagia are related. He suggested taking Prilosec OTC. I'm now on my 7th day (the pills come in a 14-day "course"), and so far so good. In the last week, I've really only had one moderately bad aerophagia night, but that was on a night that I ate a little bit too much a little bit too late.

The aerophagia hasn't really bothered me (I don't get abdominal cramps -- I just get a little bit bloated and expel a little bit of gas after I wake up). What has bothered me is upper back pain. In my first two months of therapy, I would wake up with tremendous back pain and spasms. In another thread on this forum, I've seen the back pain attributed to: sleep position, rib cage expansion (from breathing more deeply) or to aerophagia. This was what I was talking to my somnodoc about -- he suggested it was most likely due to aerophagia, which he then related to reflux. His suggestions were to use the Prilosec and to raise the head of my bed.

Guy

[Raj]

Two exercises may offer help to reduce the amount of air you swallow and both involve training muscles. First: several times a day try sticking your tongue fairly far out and keeping it out while you swallow (with an empty mouth, of course). You may find this quite challenging at first. Second: lie on your back on the floor with your knees up; lift your head an inch or two while still gazing upwards, hold a few seconds, lower your head, and relax for a few seconds. Repeat several times, gradually increasing the number of reps and how long you hold for each one until you reach at least 25 reps, holding for ten seconds (or three reps, 30 seconds each). Practice this one twice a day, but take it very easy at first since these muscles tend to be weak and easily strained even in very strong people.

[OldLincoln]

Bloating is the evil twin of CPAP therapy. A lot has been discussed in the forum about it and my comments are below.

What it is and isn't:
XPAP "bloating" is NOT digestive gas but is room air being forced through your Lower Esophageal Sphincter (LES) into your stomach which passes into your intestines and vents as does digestive gases (thankfully with less odor). Here is a good explanation of the LES function.

The primary reference to bloating on the forum is the term aerophagia, however there is an important difference between that and what's happening here. Aerophagia is swallowing air usually related to eating too fast, uncontrollable crying, or chewing gum. Swallowing is a normal function of the LES and swallowing air is considered inclusive in this process. That's why doctors are not alarmed when discussing the subject and tell you to take gas medication. However, when air is forced through your LES into the stomach it is called Gastric Insufflation (translated "push air into the stomach"). It is not a normal function and should be taken seriously.

Why is gastric insufflation important?
The medical community considers aerophagia mostly as a nuisance caused by your doing as mentioned above. They do not take that seriously and I have only read of one incident of stomach perforation and that was a newborn crying when circumcised. Also a 10 year old intellectually disabled child had a perforated colon from swallowing air.

However, gastric insufflation is taken very seriously, as it is considered not of your doing and doctors have more hands on (literally) experience with it. It is usually related to anesthesiology where the gas leaks past the mask flanges into the stomach.

How can it hurt you?
The real danger in gastric insufflation is a perforated colon dumping it's contents into your abdominal cavity, usually causing serious infection. Survival depends more on the significance of the infection than corrective procedure. In one statistical study, 38% with severe infection died while none with mild infection died, and you don't get to choose your infection level.

This is why doctors respect that term and treat it differently. While studies have made a connection between CPAP and gastric insufflation, it mostly remains in the domain of anesthesiology and some recent studies in the Paramedic use of lung inflation bags.

It's not all life and death however, before that is the pain. I compare intestinal bloating to a circus clown blowing up those cute balloons to make dogs. They blow them up a little and they can bend them to form a curve, blow them up a lot and they kink instead. In the intestines, curves are good, kinks bad. Digestive matter (and gas) are blocked until it unkinks, often when enough gas leaks through to allow it to relax.

One article was about a woman with a history of severe GIRD and OSA who used a bi-level machine. She was being treated for something else and when she inflated the doctors had quite a time tying it all together. An MRI showed the large intestine inflated and a big kink where it curves back on itself.

What's the GERD Connection?
Studies have confirmed that a history of GERD (doesn't have to be current) may have comprised your LES. The article mentioned above was a single case but they concluded that her LES was greatly weakened and the Bi-PAP was passing through the LES.

As in my case many years of GERD permanently damaged my LES. Once they invented Prilosec I tried it and haven't had a case of GERD since that I didn't deserve. Although my LES seals well (that's why I no longer have GERD), the threshold for blow-through is much lowered. If pressure remains below threshold, no gastric insufflation. There's also an excellent study to discover threshold levels. The key learning is that it's very individualized, so you need to find your own level.

What can I do about it?
When I had a fixed CPAP machine set at 10, it inflated me like a circus balloon daily and it was very painful. I actually felt like I was being ripped apart in my gut (below the stomach). I made a presentation to my doc using a logical progression of study abstracts to paint the picture of CPAP = gastric insufflation = serious consequences and that it all may be mitigated with APAP. After my presentation to the doc, he prescribed going to an APAP machine. I had given him the information he needed to defend it if the change was challenged. He originally suggested a Bi-Level but as I told him, that would give me low pressure for exhale, but high for inhale or 50% of the time.

So, I switched to an APAP which brought my average pressure into the 7's and no gastric insufflation since. While it spends most of the night at low pressure, it still races up races up to clear events then falls back. Going up I'm not getting much air anyway and after clearing it isn't there long enough (avg 15 sec) to cause harm. So for me, switching from a fixed pressure CPAP to Auto level CPAP (APAP) was the answer.

Is APAP really OK?
I think this has pretty well been put to rest on the forum, however some questions may still linger. But the machine needs to set correctly and many are not as issued. APAP's have a broad pressure range available (something like 4-20) but they have high and low limits to be set. Treatment may be less effective when the limits are set to cover the entire range.

Picture the APAP like a fire house that dispatches higher pressure when the alarm goes off. If the fire is only a few blocks away it can get there quickly, but if it's a few miles away it will take longer. Likewise if your APAP is idling along at 4 and an event that requires 14 to clear comes in your machine will take a step and see that didn't clear it then take another step and there's a lot of steps between 4 and 14. Normally a range of 6-8 seems to be generally accepted by the forum, although some want a 4 point and some OK with 10.

Finding your LES Threshold
Another neat thing about the APAP is you can reasonably test settings without betting the farm. So you can explore to discover your LES threshold. Keeping the low setting below that is key to controlling gastric insufflation, well that is if your LES is still functioning well enough to allow a decent amount of time below that magic number.

If your initial settings provide excellent relief you may simply leave well enough alone and know your threshold is above the low limit. If you still need improvement I suggest reviewing your pressure numbers first. If you have the card & software, look at the time & pressure numbers for the following (numbers over a period of time - NOT 1 night or week):

• [1.] The high reached and time (percent) spent there. If you're spending a lot of time at the high, it's not high enough. You are probably sitting there until the event clears itself. If the highest reached is well below your max setting, you may have room to slide it down. I suggest leaving 1 or more points above the highest for safety.

• [2.] The low reached and time (percent) spent there. If you are spending a lot of time at the low setting you can probably set the it even lower if comfort dictates. If you spend little time there, you can raise it if needed. Often settings below 5 or 6 cause people to feel that they don't get enough air. Then if the range between your proposed settings are within the 6 - 8 points you are doing well. If not I suggest asking for forum help.

The 90% Discussion
Whenever discussing pressure, some knowledgeable folks want to grab hold of the 90% numbers. Since I respectfully disagree I'll try to point out some rational for and against it. Although I'll attempt to state the 90% side I'm counting on a respectful dialog until it's understood (not necessarily agreed to).

90% pressure means you spend 10% of the time above that number. It's calculated by listing the pressure and time from low to high, then finding the point that represents 90% of the time used and that number is the 90% reported.

Some recommend setting the low pressure setting at the 90% number and my understanding of their position is they want to narrow the pressure range for quicker response. In the original sleep studies, many report very high numbers of events, much higher than on treatment. Therefore the treatment must be preventing events, not just clearing them. It stands to reason that the higher the constant pressure the more definite the splint to hold open the airway and thus fewer events reported. The fewer events reported the lower the AHI.

I do understand the quest to lower the AHI scores and I can appreciate those robust souls who can do that without negative consequences. They remind me of the serious sports car crowd who love to go around corners at 2.3G's riding 3 inches off the ground. But I am more the Lincoln Town Car type who appreciates a comfortable ride over the thrills.

So for those of us who are sensitive to gastric insufflation with a lower threshold than the robust, I suggest my methodology of high low and look at average pressure instead of 90%. In my case over the last 2 months my average pressure was 6.9 while my 90% was 8.8. My LES threshold is 7.5 - 8.0 so If I set my low to 8.8 I'd once again spend 100% of my time with gastric insufflation instead of 25% as I do now.

AHI Discussion
If a Zero AHI were the "holy grail" some Indiana Jones types here are already in the hunt. While I can appreciate the quest, I'm less sure of the value in it. Even those without OSA will have some events as they are simply part of life. A snore is cause by a slight obstruction in the airway but doesn't mean the person requires a life of machines and masks.

Also, keep in mind the tools used to identify an event are very imperfect. How many false positives do they report based on their electronic parameters? For example, some people tend to breath more shallow than others, do they get false positives for hypopneas.

In my own reviews, I focus on apneas and flow limitations more than hypopneas. If I had an oximeter I'd base a lot on that as I see O2 saturation as the goal of OSA treatment. Let me bumble along staying alive as long as my O2 levels are up there.

Finally, like everyone else I have good and bad nights only they don't have much correlation with my AHI scores. That's just life folks.

That's my input and I hope others get something out of it.

[Georgio]

I agree with OldLincolon.

[One Tired Puppy]

Bloating is the evil twin of CPAP therapy. A lot has been discussed in the forum about it and my comments are below.

Thanks Old Lincoln. What you have written makes a lot of sense to me. I am going to try doing it your way as soon as I get my auto machine back. It could be a couple of months so I will just keep cpap pressure lower until then.

Anne


What it is and isn't:
XPAP "bloating" is NOT digestive gas but is room air being forced through your Lower Esophageal Sphincter (LES) into your stomach which passes into your intestines and vents as does digestive gases (thankfully with less odor). Here is a good explanation of the LES function.

The primary reference to bloating on the forum is the term aerophagia, however there is an important difference between that and what's happening here. Aerophagia is swallowing air usually related to eating too fast, uncontrollable crying, or chewing gum. Swallowing is a normal function of the LES and swallowing air is considered inclusive in this process. That's why doctors are not alarmed when discussing the subject and tell you to take gas medication. However, when air is forced through your LES into the stomach it is called Gastric Insufflation (translated "push air into the stomach"). It is not a normal function and should be taken seriously.

Why is gastric insufflation important?
The medical community considers aerophagia mostly as a nuisance caused by your doing as mentioned above. They do not take that seriously and I have only read of one incident of stomach perforation and that was a newborn crying when circumcised. Also a 10 year old intellectually disabled child had a perforated colon from swallowing air.

However, gastric insufflation is taken very seriously, as it is considered not of your doing and doctors have more hands on (literally) experience with it. It is usually related to anesthesiology where the gas leaks past the mask flanges into the stomach.

How can it hurt you?
The real danger in gastric insufflation is a perforated colon dumping it's contents into your abdominal cavity, usually causing serious infection. Survival depends more on the significance of the infection than corrective procedure. In one statistical study, 38% with severe infection died while none with mild infection died, and you don't get to choose your infection level.

This is why doctors respect that term and treat it differently. While studies have made a connection between CPAP and gastric insufflation, it mostly remains in the domain of anesthesiology and some recent studies in the Paramedic use of lung inflation bags.

It's not all life and death however, before that is the pain. I compare intestinal bloating to a circus clown blowing up those cute balloons to make dogs. They blow them up a little and they can bend them to form a curve, blow them up a lot and they kink instead. In the intestines, curves are good, kinks bad. Digestive matter (and gas) are blocked until it unkinks, often when enough gas leaks through to allow it to relax.

One article was about a woman with a history of severe GIRD and OSA who used a bi-level machine. She was being treated for something else and when she inflated the doctors had quite a time tying it all together. An MRI showed the large intestine inflated and a big kink where it curves back on itself.

What's the GERD Connection?
Studies have confirmed that a history of GERD (doesn't have to be current) may have comprised your LES. The article mentioned above was a single case but they concluded that her LES was greatly weakened and the Bi-PAP was passing through the LES.

As in my case many years of GERD permanently damaged my LES. Once they invented Prilosec I tried it and haven't had a case of GERD since that I didn't deserve. Although my LES seals well (that's why I no longer have GERD), the threshold for blow-through is much lowered. If pressure remains below threshold, no gastric insufflation. There's also an excellent study to discover threshold levels. The key learning is that it's very individualized, so you need to find your own level.

What can I do about it?
When I had a fixed CPAP machine set at 10, it inflated me like a circus balloon daily and it was very painful. I actually felt like I was being ripped apart in my gut (below the stomach). I made a presentation to my doc using a logical progression of study abstracts to paint the picture of CPAP = gastric insufflation = serious consequences and that it all may be mitigated with APAP. After my presentation to the doc, he prescribed going to an APAP machine. I had given him the information he needed to defend it if the change was challenged. He originally suggested a Bi-Level but as I told him, that would give me low pressure for exhale, but high for inhale or 50% of the time.

So, I switched to an APAP which brought my average pressure into the 7's and no gastric insufflation since. While it spends most of the night at low pressure, it still races up races up to clear events then falls back. Going up I'm not getting much air anyway and after clearing it isn't there long enough (avg 15 sec) to cause harm. So for me, switching from a fixed pressure CPAP to Auto level CPAP (APAP) was the answer.

Is APAP really OK?
I think this has pretty well been put to rest on the forum, however some questions may still linger. But the machine needs to set correctly and many are not as issued. APAP's have a broad pressure range available (something like 4-20) but they have high and low limits to be set. Treatment may be less effective when the limits are set to cover the entire range.

Picture the APAP like a fire house that dispatches higher pressure when the alarm goes off. If the fire is only a few blocks away it can get there quickly, but if it's a few miles away it will take longer. Likewise if your APAP is idling along at 4 and an event that requires 14 to clear comes in your machine will take a step and see that didn't clear it then take another step and there's a lot of steps between 4 and 14. Normally a range of 6-8 seems to be generally accepted by the forum, although some want a 4 point and some OK with 10.

Finding your LES Threshold
Another neat thing about the APAP is you can reasonably test settings without betting the farm. So you can explore to discover your LES threshold. Keeping the low setting below that is key to controlling gastric insufflation, well that is if your LES is still functioning well enough to allow a decent amount of time below that magic number.

If your initial settings provide excellent relief you may simply leave well enough alone and know your threshold is above the low limit. If you still need improvement I suggest reviewing your pressure numbers first. If you have the card & software, look at the time & pressure numbers for the following (numbers over a period of time - NOT 1 night or week):

• [1.] The high reached and time (percent) spent there. If you're spending a lot of time at the high, it's not high enough. You are probably sitting there until the event clears itself. If the highest reached is well below your max setting, you may have room to slide it down. I suggest leaving 1 or more points above the highest for safety.

• [2.] The low reached and time (percent) spent there. If you are spending a lot of time at the low setting you can probably set the it even lower if comfort dictates. If you spend little time there, you can raise it if needed. Often settings below 5 or 6 cause people to feel that they don't get enough air. Then if the range between your proposed settings are within the 6 - 8 points you are doing well. If not I suggest asking for forum help.

The 90% Discussion
Whenever discussing pressure, some knowledgeable folks want to grab hold of the 90% numbers. Since I respectfully disagree I'll try to point out some rational for and against it. Although I'll attempt to state the 90% side I'm counting on a respectful dialog until it's understood (not necessarily agreed to).

90% pressure means you spend 10% of the time above that number. It's calculated by listing the pressure and time from low to high, then finding the point that represents 90% of the time used and that number is the 90% reported.

Some recommend setting the low pressure setting at the 90% number and my understanding of their position is they want to narrow the pressure range for quicker response. In the original sleep studies, many report very high numbers of events, much higher than on treatment. Therefore the treatment must be preventing events, not just clearing them. It stands to reason that the higher the constant pressure the more definite the splint to hold open the airway and thus fewer events reported. The fewer events reported the lower the AHI.

I do understand the quest to lower the AHI scores and I can appreciate those robust souls who can do that without negative consequences. They remind me of the serious sports car crowd who love to go around corners at 2.3G's riding 3 inches off the ground. But I am more the Lincoln Town Car type who appreciates a comfortable ride over the thrills.

So for those of us who are sensitive to gastric insufflation with a lower threshold than the robust, I suggest my methodology of high low and look at average pressure instead of 90%. In my case over the last 2 months my average pressure was 6.9 while my 90% was 8.8. My LES threshold is 7.5 - 8.0 so If I set my low to 8.8 I'd once again spend 100% of my time with gastric insufflation instead of 25% as I do now.

AHI Discussion
If a Zero AHI were the "holy grail" some Indiana Jones types here are already in the hunt. While I can appreciate the quest, I'm less sure of the value in it. Even those without OSA will have some events as they are simply part of life. A snore is cause by a slight obstruction in the airway but doesn't mean the person requires a life of machines and masks.

Also, keep in mind the tools used to identify an event are very imperfect. How many false positives do they report based on their electronic parameters? For example, some people tend to breath more shallow than others, do they get false positives for hypopneas.

In my own reviews, I focus on apneas and flow limitations more than hypopneas. If I had an oximeter I'd base a lot on that as I see O2 saturation as the goal of OSA treatment. Let me bumble along staying alive as long as my O2 levels are up there.

Finally, like everyone else I have good and bad nights only they don't have much correlation with my AHI scores. That's just life folks.

That's my input and I hope others get something out of it.

[TSSleepy]

Thanks Old Lincoln for this great post. I am about 12 days into my life as a hosehead and have been trying to titrate myself.

10 cm H2O CPAP with C-Flex @ 2 = a little gas
11 cm H2O CPAP with C-Flex @ 1 = a disaster of biblical proportions

When I started searching about for answers about aerophagia, bloating, gas... your post really helped!

[SacramentoGranny]

One quick question to TSSleepy -- why are you using your APAP in CPAP mode? And why in C-Flex instead of A-Flex? If you know how to set the machine, try Auto with A-Flex. The difference will be spectacular.

[dowen]

OldLincoln

Your post is a keeper. I've bookmarked it. I'm fairly new to the PAP game and in the past week, in an attempt to see if I could lower my AHI score, I've been increasing my minimum pressure and reducing my EPS.

The result - I think I unintentionally found my LES threshhold. (But I didn't know that's what I'd done till I read your post. )

Now I know.

thanks

[Lee Lee]

Old Lincoln,
Wonderful, thoughful and informative post! Everyone with this issue should bookmark it. (I have all of the above!)
I appreciate your taking the time to do this.
Lee Lee

[TSSleepy]

One quick question to TSSleepy -- why are you using your APAP in CPAP mode? And why in C-Flex instead of A-Flex? If you know how to set the machine, try Auto with A-Flex. The difference will be spectacular.

My post from back in early March was before I got my A-Flex machine. My signature apparently got retroactively updated.

I am now using level three A-Flex and like it much better than C-Flex.

The smoother the transition between inhaling and exhaling...the better my bowels seem to like it!

I'm also using a 10-12 auto range, which is nice. My "90% pressure" using that range is around 11.8, so some might think that I might want to bump that lower number up (as Old Lincoln mentions in his "The 90% Discussion" section).

But my average is usually down around 10.5 and I am at 10.0 for large portions of the night. A straight CPAP at 12 would probably give me the same sleep apnea therapy, but significantly more aerophagia based on my early experiments.

If I open up the range to 10-20, the auto wants to ramp up to 14-15 pressure for large portions of the night and I end up with very bad gas without any real benefit to my apneas, AHI, or oxygen levels.

Now that I have a 10-12 auto setting and full A-Flex, my aerophagia is pretty minor. A little belching and farting the first hour I'm awake. I usually have it all taken care of before the morning commute.

[2flamingos]

Much thanks to Old Lincoln for the post and veryone else for their comments - I think it has helped me understand a little better the 90% and average pressure issue. Iwas concerned that my 90% number was my max setting, but after looking at my averages - I average 11.8 - so not too bad. Once in a while I have those back AHI nights (have had a few that were over 10), but overall may average is between 4.8 and 5.4. WOuld like it a little lower, but then again, it is usually split between OA and H, and usually close to an equal split. My best night that I am aware of was only 1.6 OA.... yippee.

Again, much thanks for all the helpful info.

[chunkyfrog]

Old thread, bumped by worthless spam--deleted same.
Talk amongst yourselves; have some pastry.

[Sir NoddinOff]

WOW... Old Lincoln. That's some depth of research and knowledge. I'm totally impressed. I can't judge if all the presented conclusions/conjectures are true, but I totally respect the way you put your case before us. Massive kudos. It certainly deserves more research and discussion on this site!