APAP vs. BiPAP for aerophagia

momexp5 · Post by **momexp5** » Thu Jul 28, 2005 11:45 am

Hello veterans, pleeeease help me with this today! I am in the fortuitous position of having a doctor who is more than ready to write me prescriptions for anything I want. I mentioned "aerophagia" and right away he said "bipap" but then after we chatted he said "autopap!" but I'm not sure that's the right conclusion here, so here I am to consult with y'all.

Am I writing too train-of-thought today? Sorry.

Anyway - my main problem is air in the stomach. Right now I have a REMStar Plus. Being a leprechaun, I don't need high pressures, but even at 8, and 7, and even 6, even with CFlex, I get air in the tummy. What's better for this? The doctor said BiPAP because it would drop more than CFlex on exhale. But then - I think just because I said "what about AutoPAP?" in an interested way, he said "sure, you can try that" - BUT does AutoPAP CFlex have the ability to drop as far down as a BiPAP?

"Aerophagia at low pressures - what's better, APAP or BiPAP, and why?"

Helllllp.... and if anyone has better drugs than the ones I'm evidently mysteriously on today, please let me know.

:::feeling bizarrely goofy:::

ozij · Post by **ozij** » Thu Jul 28, 2005 12:06 pm

I have no experience with bi-pap, but I do know that bi-pap has you on a constant inhale pressure, and a differet, lower exhale pressure.

An autopap on the other hand can vary your pressure - inhale and exhale - according to your need, which might change as you position change, and which might change from night to night. Which mean APAP won't give you long periods of high pressure, unless there are indications the pressure is necessary to keep the airway open.

You might find yourself having to set the inhale pressure on the bi-pap at a higher overall level than what you get using APAP. My apap is presently 5-10. It never reaches 10. The precentage of time I spend at each pressure is as follows:
5 56.56
6 24.21
7 8.7
8 5.05
9 5.28

You won't get that responsivness to bi-pap.

The following is a real (not rhetorical) question: Do we have any reason to thing aerophagia happens because to the exhale pressuer being too high? If we do, then bi-pap is a possible solution. If aerophagia is pressure related, but not specifically exhale pressure related, then APAP is a better idea.

APAPs are cheaper too.

O.

th · Post by th » Thu Jul 28, 2005 12:07 pm

momexp5
IMO
One nice thing about an auto with c flex is you might never reach the pressure you were titrated for. My wife was titrated at 9 . With the remstar auto with C/Flex she never reaches 9 her apnea is corrected at 6 or 7. I spend most of night at 6 and 7 To me you would be better off with the auto since you would be taking in less air most of the night..........just my .02

th

WillSucceed · Post by **WillSucceed** » Thu Jul 28, 2005 12:45 pm

I think ozji has hit the nail on the head. Take a look at what is causing the aerophagia. It is unlikely that you are swallowing air when you are exhaling. Try to exhale and swallow at the same time right now... can't do it, can you??

I believe that aerophagia is a dynamic of swallowing air just before, while, or just after inhaling. A bi-pap will give you the same pressure upon inhalation all night long. This pressure will be the highest that you need based on the titration study, but, you are unlikely to need this pressure ALL night long. You probably only need the higher pressure when you are in the deepest stages of sleep, and REM.

An autoPAP (forget C-FLEX for the moment) will give you consistently lower pressures during the night and will only give you higher pressures when you need it. Overall, you will likely swallow less air and have less discomfort.

Back to C-FLEX... you mentioned pressures of 8, 7 & 6, these are relatively low pressures and C-FLEX does not give much relief at these pressures because there is not much room to drop down to. It's unlikely that C-FLEX will make for LESS aerophagia.

I used a RemStar Plus with C-FLEX (non-auto machine) at a pressure of 15. Damn near killed me with aerophagia and I got no help from C-FLEX. I switched to an auto machine and spend the bulk of the night at a pressure of 8, with periodic spikes as high as 11. Aerophagia gone, gone, thank-the-spirits it's gone.

I'd encourage you to try out an auto machine, or several, if possible, to find the one that works best for you. Bear in mind that all of the different manufacturers use different software algorithms in their machines. Get a C-FLEX machine if you want it, but bear in mind that at low pressures, C-FLEX is not doing much. Look at all of the options that are available before you make your decision. All of these machines can function in straight CPAP mode if you wish, and all of them are relatively quiet and easy to use.

ResMed Spirit or software-upgraded L7 Elite:
Big and bulky, humidifier a bit of a pain to manage, machine allows for checking mask leak and you can tell the device which ResMed mask you are using. Also has the ability to add a module that measures oxygen saturation. Can't tweak any of the settings relative to how the machine does what it does. Has no C-FLEX - like pressure relief on exhalation.

Respironics RemStar Auto with C-FLEX:
Big and bulky, has C-FLEX pressure relief on exhalation (which can be disabled if you wish), has a great humidifier system. Can't add any modules to measure oxygen. Can't tell machine which mask you are using, can't tweak any setting relative to how the machine does what it does.

Puritan-Bennett 420E:
Very small and lightweight, has no C-FLEX - like pressure relief on exhalation, has a great humidifier system. Can't add any modules to measure oxygen. Don't need to tell the machine what mask you are using as it has a dedicated pressure sensor line in the air hose -measures pressure at the mask which, some think, is more accurate than the other machines. Has several triggers that user can tweak allowing for fine-tuning of how the machine does what it does.

momexp5 · Post by **momexp5** » Thu Jul 28, 2005 4:00 pm

ozij wrote: The following is a real (not rhetorical) question: Do we have any reason to thing aerophagia happens because to the exhale pressuer being too high? If we do, then bi-pap is a possible solution. If aerophagia is pressure related, but not specifically exhale pressure related, then APAP is a better idea.

That seemed to be my doctor's first thought - that the aerophagia was from the exhale pressure being too high, and therefore, BiPAP.

I just read someone here saying, too, that with low pressures, the CFlex provides relatively less exhale pressure relief.

So, I guess I'm trying to figure out whether APAP's routine includes acting like a BiPAP on exhale. Or if it can be set that way, to have a fixed exhale pressure.

momexp5 · Post by **momexp5** » Thu Jul 28, 2005 4:09 pm

WillSucceed wrote:I think ozji has hit the nail on the head. Take a look at what is causing the aerophagia. It is unlikely that you are swallowing air when you are exhaling. Try to exhale and swallow at the same time right now... can't do it, can you??

:::imagining::: I could see where there could be a bubble of air sitting at the base of my throat which doesn't quite get blown out with an exhale. And it's not like I'm swallowing to make the air go into my stomach - it's more like it's a bubble that migrates to my stomach. Only relief I get from it is sleeping on my back with my head somewhat elevated. I don't like sleeping on my back at all.

Back to C-FLEX... you mentioned pressures of 8, 7 & 6, these are relatively low pressures and C-FLEX does not give much relief at these pressures because there is not much room to drop down to. It's unlikely that C-FLEX will make for LESS aerophagia.

<bwg> Ah! Yes, it was yourself that I just quoted in my last post, from when you've posted about that elsewhere - see, I've been paying much attention!

All of these (auto) machines can function in straight CPAP mode

I think what I need to know is whether they can also function in a BiPAP sort of mode.

Thanks for the advice, sweetie.

Guest · Post by **Guest** » Thu Jul 28, 2005 5:09 pm

I always thought cpap induced aerophagia did not entail a coordinated "swallowing" of air while asleep. Rather, that CPAP pressure is simply high enough to breech the esophageal sphincter muscles.

I believe this air pressure breech process is even suspected to be more prevalent during EPAP than it is during IPAP... which is why doctors very often prescribe BiLevel for aerophagia. APAP also works well for many suffering from aerophagia since it strives to brings the mean airway pressure or "MAP" down.

coffee · Post by **coffee** » Thu Jul 28, 2005 5:52 pm

I haven't used a bipap, but I have had some relief from aerophagia since switching from cpap at 11, to apap at 8-14. I believe this is from reducing the mean pressure during the night. Often the pressure stays around 9, rising only intermittingly. I now have the machine set at 9-15 with a bit more air in the stomach. When I tried it at 10-14 I woke up with painful aerophagia the next morning.
I'm playing with the pressure in an attempt to lower my AHI which has stayed around 7-10, only dropping below 5 on three occasions. I have also played a bit with the cflex setting, the lower the number (less exhalation relief) the better the AHI seems to be.

Tweaking the masks, mouth leaks, the pressure, the cflex, the aerophagia... makes the old days of tracheotomies sound good!

WillSucceed · Post by **WillSucceed** » Thu Jul 28, 2005 8:15 pm

Coffee wrote:

Tweaking the masks, mouth leaks, the pressure, the cflex, the aerophagia... makes the old days of tracheotomies sound good!

Forgive me for saying this but... ARE YOU OUT OF YOUR MIND?!?!?!
It does not make the old days of having a hole drilled through your throat that you have to cork just to be able to speak sound good. Sheesh! I'm sure that you are kidding but please, don't even suggest it!

I'm not aware that bi-pap is the cure for aerophagea. It certainly can be the cure for people that cannot tolerate exhaling against a high pressure, but there are lots of folk who can't tolerate exhaling against the pressure and don't have aerophagea. Stick you head out of the car while travelling at 100klm's and see if it is difficult to exhale (example given to me by one of the Respirologists at work). Difficulty exhaling does not necessarily mean that you are swallowing air. Also, there are people at relatively low pressures that swallow lots of air (and have the associated belching/farting) as well.

Anyway, maybe bi-pap is the cure for aerophagea. I am inclined to think that aerophagea is the result of having consistently high pressure all night. When I was at a pressure of 15, using C-FLEX of 3, I had horrible aerophagia. Changing the C-FLEX setting did not make any difference. When I changed to an autoPAP, and had consistently lower pressures during the night (average of 9) with no C-FLEX, the aerophagea was gone.

Guest wrote:

CPAP pressure is simply high enough to breech the esophageal sphincter muscles.

The point of the pressure is to splint your airway open, not blast it open. The titration study will determine the pressure that the patient needs to keep the airway open when the patient is in the deepest state of sleep (muscle tone at it's lowest). This deepest sleep/lowest muscle tone happens several times during the night. The majority of the night is NOT spent in the deepest stages of sleep and muscle tone during these periods is higher -->higher air pressures are not likely to be needed to keep the airway splinted open because the muscles are doing it.

So, if high pressure is the culprit of aerophagea, an autoPAP, by design, will give longer periods of lower pressure over the course of the night which should help reduce the aerophagea. If higher pressures during exhalation is the culprit, then a bi-pap should help but, so too would autoPAP as lower pressure overall is still lower pressure.

There are theories that the changes of pressure during the night that the autoPAP does can cause micro-arousals. However, regarding CPAP and Bi-pap, once the patient gets used to the single pressure of CPAP and/or the consistent inhalation pressure/exhalation pressure of bi-pap, micro-arousals should lessen. I'm inclined to believe that autoPAP does cause some micro-arousals, and find that I do best (seem to sleep the best) when I have the lower pressure bumped up somewhat.

For example, I was titrated in the sleep clinic and prescribed CPAP of 15; I could not stand it. So, I trialed some autoPAP machines which all said I only need 9 for 90% of the night. I lost some weight and the autoPAP reported that I only need 8 for 90% of the night. So, rather than have the autoPAP set for a range of 5-13, which is what the Sleep Quack ordered, I have it set for 8-13. I did this because at the range of 5-13, I was spending much of the night down around 5, 6 & 7, but was also going as high as 11. The autoPAP was doing its job wonderfully, working hard all night adjusting pressure to splint my airway open but, I was waking up many times during the night by something -->I think it was the pressure change.

With the pressure set at 8-13, I spend almost the entire night at 8, with a few periods up around 10 and, sometimes, 11. So, what I think I have accomplished is staying at a steady pressure of 8 (like a single CPAP pressure) which keeps my airway open, does not cause aerophagea and does not wake me by pressure changes. For those few periods during the night when I need even more pressure (deepest stages of sleep/REM) the autoPAP gives me what I need.

So, what I am getting is more pressure than I need for much of the night (defeats the purpose of autoPAP) but this pressure is not enough to give me aerophagea, AND higher pressure for those few periods when I need it (the beauty of autoPAP) with an overall reduction in the number and range of pressure changes in an effort to avoid pressure-change induced micro-arousals.

Clear as mud? Make sense?

Guest · Post by **Guest** » Thu Jul 28, 2005 8:36 pm

There are people not on CPAP with aerophagia. That would be a coordinated muscular swallowing of air. Those same people may find their way to CPAP and have the same type of aerophagia that is associated with swallowing.

CPAP pressure breeching the esophagus sphincter muscles... without any muscle-coordinated swallowing by the patient. That is CPAP induced aerophagia of a different airway mechanism altogether. So... during exhalation the pressure against the esophagus will momentarily reach a maximum with the assistance of the diaphragm and CPAP acting together. That is why aerophagia tends to happen more during exhale in some patients instead of inhale. And that is why BiLevel gets prescribed to help in those cases. Again, APAP helps too!

rested gal · Post by **rested gal** » Thu Jul 28, 2005 9:30 pm

Good points by Guest, Willsucceed, coffee, ozij, th and momexp5!

Anecdote:

I usually use an autopap - range 8 - 15. The machine rarely touches 13, occasionally hits 12 for brief periods, but usually stays in the 8-11 range. No aerophagia at all except for a few nights when I experimentally set it for various straight pressures. Aerophagia occurs for me at any straight pressure 12 and above, worse as the straight pressure is upped.

A month or two ago I had an opportunity to use two different bi-level machines. Respironics BiPAP PRO and ResMed VPAP III ST A.

As long as I kept the IPAP at 11 on either of those machines (I played around with EPAP, but usually kept EPAP on 8 ) I got no aerophagia. If I set IPAP on 12, some aerophagia crept in. Enough to be uncomfortable. At 13 it arrived with a vengeance. The abdominal pain from aerophagia was intolerable to me...I'm a wimp, yes.

Using the machine, if I deliberately relaxed my throat as much as possible while lying there awake, I could literally feel a bubble of air forming in my throat, about where a man's Adam's Apple would be, much as momexp5 described. I didn't want it to go on down the esophagus which is where it felt like it was just waiting to go. It was work to expel it with a soundless burp. I had to pull my shoulders way back to get it to "rise" to burp status against the incoming pressure ( 8 ) while the bi-level was waiting for me to start another breath. (Gawd, the things we tell!)

Anyway, feeling that happen in my throat over and over again while awake on the bi-level machines at IPAP 12 or 13 made me realize what was probably going on during my sleep - I was either swallowing each trapped bubble of air, or perhaps they were finally being forced on down my esophagus. I was NOT a happy camper with a straight 12 for inhaling. One cm down at IPAP 11 and none of that happened.

I have an adjustable bed. Raising the head of the bed did not prevent it.

Luckily IPAP 11 / EPAP 8 treated me fine on both the two bi-level machines. If I required a pressure of 12 or above for IPAP on a bi-level, or on a straight CPAP machine, I'd be suffering. But not for long. I'd be doing whatever it took to get an autopap in hopes of being able to spend more treatment time down at lower pressures. I would not want to wait to see if I'd ever get used to it.

Guest's comment makes sense to me:

I always thought cpap induced aerophagia did not entail a coordinated "swallowing" of air while asleep. Rather, that CPAP pressure is simply high enough to breech the esophageal sphincter muscles.

I believe this air pressure breech process is even suspected to be more prevalent during EPAP than it is during IPAP... which is why doctors very often prescribe BiLevel for aerophagia.

Since the low pressure of my autopap is set for 8, and the EPAP was at 8 for most of my bi-level experiments, 8 doesn't seem to breech my esophageal sphincter. I suppose I really was swallowing air in my sleep at the steady pressure of IPAP 12.

Guest · Post by **Guest** » Thu Jul 28, 2005 9:43 pm

Great anecdote, Rested. APAP and BiLevel both help with aerophagia. Some folks seem to have better luck combatting aerophagia with an APAP machine while other folks seem to have better luck using BiLevel.

I guess it all depends on the exact nature of their aerophagia. Are they muscle discoordinate swallowers or are they passive breechers? It would also depend on how much time their APAP manages to stay near the bottom of their pressure range instead of frequently being near the top.

rested gal · Post by **rested gal** » Thu Jul 28, 2005 9:49 pm

Guest, you remind me of someone that I miss.

Thanks for your help. I did wonder...am I swallowing the air, or is it being actually forced down? You cleared up that minor mystery. I didn't lose sleep over the mystery but I do like to know what's happening.

momexp5, I'm glad you brought it up. No pun intended!

coffee · Post by **coffee** » Fri Jul 29, 2005 8:52 am

Coffee wrote:
Quote:
Tweaking the masks, mouth leaks, the pressure, the cflex, the aerophagia... makes the old days of tracheotomies sound good!

Forgive me for saying this but... ARE YOU OUT OF YOUR MIND?!?!?!
It does not make the old days of having a hole drilled through your throat that you have to cork just to be able to speak sound good. Sheesh! I'm sure that you are kidding but please, don't even suggest it!

I WAS ONLY KIDDING!
Please, no self-inflicted tracheotomies because of me!

All of these comments are very interesting and with all these great minds out there we should hopefully have a remedy eventually. Unfortunately, the so-called experts (sleep doctors & RTs) still seem to dismiss aerophagia as only effecting a small number of xpapers and thus not important enough for serious study...
These forums are great! Thanks everybody.

momexp5 · Post by **momexp5** » Fri Jul 29, 2005 10:45 am

coffee wrote: Tweaking the masks, mouth leaks, the pressure, the cflex, the aerophagia... makes the old days of tracheotomies sound good!

och, could you *imagine* having to go through that? People living now are in *such* a different world healthwise, and this is just one more example of that. We are blessed at least in that way.