How does mask leak affect AHI?

I need some more education, please, about how this all works. At the risk of inviting ridicule, I'm going to summarize what I think happens with CPAP, and then I would happily be corrected or educated further.

When we have an "event", the machine blasts the pressure at us to try to open up the airway. Under that pressure, is that what causes the mask to leak...or is the mask already leaking allowing the pressurized air to escape so that it doesn't avert the event? Kind of a chicken and egg question, I guess. I'm going to show the details of my nap this morning when I went back to bed after working a couple hours. There is a whopping section of OAs and, in my view anyway, it seems it correlates to a lot of leakage with the mask. I am not really a wild sleeper. My RLS is very well controlled with Requip, and I pretty much just shift from side to side and then stay there until I get uncomfortable and shift back over to the other side. So I don't think I'm causing the leaks but don't know. Short of finding a wonder mask (and, believe me, this is the best one I've tried so far, lowest leakage and most comfortable), is there anything I can do mask-wise to bring down the events?



Thank you!

Peggy

P.S. Also I have a question about my M Series "integrated" humidifier. I just got my first Explanation of Benefits from my insurance company. Apparently my DME "does not participate in patient's health care plan", and so no adjustments will made to what they are charging and the insurance company is kicking in very little, about a third of the total cost. I'm going to just buy my own machine on CPAP.com and return the CPAP to them since it is just being rented at this point, but apparently the humidifier is consiered a "purchased product" and likely cannot be returned. Since it is "integrated", am I screwed if I get an entirely different brand of CPAP/APAP or can I still use it with any xPAP machine I get?

I could be wrong here but I think it is just the plastic container that holds the water - not the entire HH - they are talking about.

Peggy, I am so glad you are staying with the program.

Have you considered calling your doc and telling him that you are going to have to pay for all your equipment out of pocket and don't want to waste it or have to buy another machine later, so would he give you a rx (letter of need for 99 years) for a auto bipap set to operate to your present prescription so you don't have to go through titration again. The (now obsolete) tank type auto bi-pap goes for $899 complete with the humidifier if you can find one still in stock or get cpap.com to price match that price. I say that because you have centrals and it would give the doctor a lot more flexibility in treating your condition for $300 more to start. The M Series Auto w aflex is $526 or $596 with humidifier. Order your equipment online and get it running before returning the equipment leased and you will not miss a night. Don't pay for the humidifier from the DME without a fight. In spite of what they say, they lease humidifiers, too, and since if you choose to order the m-series, you can get the identical humidifier for $70 more, you sure shouldn't have to pay more than that for it or give them the new one and tell them to charge you nothing.

pjwalman wrote:I need some more education, please, about how this all works. At the risk of inviting ridicule, I'm going to summarize what I think happens with CPAP, and then I would happily be corrected or educated further.

When we have an "event", the machine blasts the pressure at us to try to open up the airway. Under that pressure, is that what causes the mask to leak...or is the mask already leaking allowing the pressurized air to escape so that it doesn't avert the event? Kind of a chicken and egg question, I guess. I'm going to show the details of my nap this morning when I went back to bed after working a couple hours. There is a whopping section of OAs and, in my view anyway, it seems it correlates to a lot of leakage with the mask. I am not really a wild sleeper. My RLS is very well controlled with Requip, and I pretty much just shift from side to side and then stay there until I get uncomfortable and shift back over to the other side. So I don't think I'm causing the leaks but don't know. Short of finding a wonder mask (and, believe me, this is the best one I've tried so far, lowest leakage and most comfortable), is there anything I can do mask-wise to bring down the events?], DME

The leaks look pretty good to me, although I certainly don't qualify as experienced! You are really fighting a battle, because the one central you had causes the auto to cut back on the pressure right in the middle of those apneas you were having. Yes, there will always be more leaks as the pressure is increasing, fortunately, the machine senses this and raises the output volume of air to maintain the pressure under leaks. While that works fairly well for full face masks, it does not work for mouth breathing leaks with nasal masks as the pressure in then shunted away from the apnea.

You might gain some insight on the leak issue by reading these two threads. Not everyone agrees on things.

viewtopic.php?p=258360

viewtopic.php?p=258122

pjwalman wrote:When we have an "event", the machine blasts the pressure at us to try to open up the airway.

Funny you should ask. We had a lengthy "discussion" about this very subject recently involving review of lots of Respironics material. The short answer is your description is close. From the information reviewed, it appears that the Respironics algorithm doesn't increase pressure during that first apnea at all, instead waiting until some time during an ensuing apnea before increasing pressure.

pjwalman wrote:Under that pressure, is that what causes the mask to leak...or is the mask already leaking allowing the pressurized air to escape so that it doesn't avert the event? Kind of a chicken and egg question, I guess.

Interesting question. My "guess" is that the small spikes may not be actual leaks at all but related to the way the machine calculates leakage. The amount of air being moved changes considerably whenever an apnea occurs, but the machine doesn't/can't recognize that immediately and so some artifacts are presented. Notice also that most of those "leaks" have a one-digit resolution (LSB), so the measurement itself is, at best, crude in terms of accuracy.

Your data looks pretty valid. The complaints you may have read about "leaks" affecting results usually occur when leakage approach the LL, or "Large Leak" level as defined by Respironics. At the LL level, the Respironics algorithm can no longer provide accurate results. Respironics recognizes that and whenever LL occurs "zeroes out" all the data.

pjwalman wrote: ... the insurance company is kicking in very little, about a third of the total cost. I'm going to just buy my own machine on CPAP.com and return the CPAP to them since it is just being rented at this point ...

You might see if they will reimburse you for that same exact dollar amount if you purchase your equipment from an online provider. Many will reimburse you directly if you purchase your equipment directly and submit the claim. Mine did.

pjwalman wrote: ... apparently the humidifier is consiered a "purchased product" and likely cannot be returned. Since it is "integrated", am I screwed if I get an entirely different brand of CPAP/APAP or can I still use it with any xPAP machine I get?

I think I'd be protesting to the DME. That policy makes little logical sense to me. It sure won't hurt to protest that one. Don't be so quick to fire your local DME. They may still offer some benefit to you. Say, for instance, you want to try out the 420E APAP. With the prospect of renting the PB420E as a "carrot", the DME may be more receptive to allowing return of the integrated humidifier. So, then rent the 420E, but without its integrated humidifier. Instead, purchase a stand-alone humidifier online. If the 420E works better for you, then purchase it online. Otherwise, I'd suggest a trial of the ResMed S8 Vantage APAP. And the old BiPAP-auto machine is a good suggestion as well. When you exhaust possibilities (or your own patience) buy whichever of the machines works best for you.

As for the integrated humidifier, I'm sure some creative person could come up with a way to use it with a different machine but, personally, I doubt that it's be worth the time and effort.

Regards,
Bill

Thank you, all! Honestly, it's just one of those days I want to sit down and bawl, still exhausted even after getting a decent night's sleep and that huge nap and overwhelmed by the amount of money I now owe to medical providers.

WW, that is an excellent idea...except that I had to practically beg my doctor to let me go to APAP, and he doesn't believe my centrals are real centrals so wouldn't see the validity of my having a BiPAP. It's obvious he thinks I am an irritating twit, and some on this forum would likely agree.

NightHawkeye, that is a good suggestion about the humidifier. I can at least suggest that that insurance company's whopping 150.61 payment towards the 385 they want for the humidifier be returned to them and maybe they'd consider it having been a rental instead of a purchase then. Now that I see how useless an integrated humidifer is when you have a switch in equipment, I think it is an excellent suggestion to go with something totally self-sufficient.

I want to thank you all for your help and support! My spirits are seriously flagging all of a sudden (fancy expression for heading into the dumper), and it really helps to have you here!

Take care!

Peggy

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CPAPopedia Keywords Contained In This Post (Click For Definition): bipap, humidifier, APAP

In spite of what they say, they lease humidifiers, too, and since if you choose to order the m-series, you can get the identical humidifier for $70 more, you sure shouldn't have to pay more than that for it or give them the new one and tell them to charge you nothing.

WW, I just reread your post, and I had missed this the first time. That is a brilliant idea: Giving them the new one I buy and them charging nothing then!! Only if they choose to be total jerks could they refuse *that* offer!

Thank you for the great idea!!!

Peggy

Well, you win some, you lose some...and if you're really in sleep debt, you cry on the phone to the billing office lady. How humiliating! Man, my emotions are raw lately, and I hate that!

So on the DME not participating in my health plan, they say they told me, even made a note about it. I don't think so, but she pointed out that sleep-deprived people often don't remember things that are told to them, which is why the DME tech wrote it down, and it's hard to argue with that one, now isn't it? But they did adjust the bill and give me the 50% co-pay as a gesture of goodwill, which cut $150 off my bill, so that is a win somewhat.

What I lost on is the humidifier. They consider it a supply and wouldn't even consider allowing me to return a new humidifier in its place. Lady "generously" said I could return it anyway if I wanted to. Gee, wasn't that nice of her? But otherwise that I could use it as a planter or whatever I wanted -- not her problem if I would have no use for it.

So I'm returning the machine on my day off on Friday. They won't make me pay a prorated rate for the time since the 3rd when the first month rental was up. I don't see why I should worry about them printing off my data since the insurance company has already paid for the first month, so this way they won't have to know I've been dinking with things on my own. I will use my father-in-law's RemStar Plus and just deal with the aerophagia until the PB comes for a visit, and I will eventually try to sell my humidifier, software, and two card readers if I end up going with something other than the M Series, which I likely will. Live and learn. Right?

Wish I didn't have this sour taste in my mouth, but it's my own fault apparently for not being more savvy.

Peggy

LOL you sure are a basket case

My opinion:

In this "case" LEAK is NOT your problem, a stubborn tongue is.

Yes as mentioned before even 10 cm pressure can be too much as evidenced by that cluster or hour of OA's, but in this case that is NOT the cause, where is Bill's cork theory

IF "leak" where your problem, where your machine couldn't keep up, it would have to climb above 75L/m then stay there for a while. This would then show up at the top of the same Leak graph as "LL" for Large Leak, it would also place a sold BLACK bar at the top of the chart, that tells you when the machine can no longer compensate for leak where it begins to impact your treatment. Your Large Leak on the right side shows NO Large Leak with 0.0 minutes.

Notice you have another "NR" during that period? see the single snore below and in front of that train wreck?

Then see very few events before and after that period?

Again your AHI=7 shown is very misleading forget about it.

In "this case" central apnea is also NOT your problem.

My dear you fell asleep, relaxed too much and probably hit REM, this allowed things to relax so much you began snoring (have picture in mind of cartoon with walls of house expanding out as you snore).

In this case that "NR" means just that "No or non-response. Meaning something has prevented the machine's pressure advances from dislodging the obstruction, most likely your tongue.

Looking at that report, I'd say you have a tongue lodged in the airway that it would take a crane to pull back out.

And I know why too, your mask, Full Face mask is a no-no for you.

Your report says to me you began to snore, when you snore you are on the very edge of an apnea, that sequence of events seems to confirm it, I say this because:

You are most likely "inhaling" during that snore, it is akin to sucking up your underwear accidently with the vacuum cleaner, you get close and "whamo" its gone.

That underwear is pretty much what your tongue does as you are snoring during inhale, the low pressure in your esophagus combined with about 14.7 PSI, why that is nearly half as much pressure you probably have in your automobile tires, so atmospheric pressure pushes and low pressure behind sucks the tongue back into the throat hole,

then the CPAP pressure (due to use of current full face mask bad leverage characteristics) cannot leverage the tongue back out, so the machine keeps trying and trying, tosses up a NR flag,

Once NR flag is thrown, machine stops trying (keeps recording) and finally you cannot breathe any longer so your fight or flight response kicks in, restores stability to the tongue & throat muscles to clear the airway your tongue dislodges and you wake up going WTF.

Not much you can do about that but toss the current mask,

you NEED a nasal mask so the CPAP splint pressure has greater leverage where it can more easily dislodge your tongue.

the result for you will be lower pressure needed to keep things splinted. You will need to either tape your mouth or learn NOT to mouth breathe. That means you may also have to address any allergies and/or nasal congestion.

Did I explain it simple enough?

LOL

P.S. That 10 cm pressure (current minimum) is pretty close to your ideal pressure, subtract that train wreck from the mess above and you had a pretty eventless night if it wasn't for that cork/tongue lodging itself in the airway. Use a nasal mask at that same pressure, control leaks and you will probably obtain ideal therapy if there is such a thing.

Certainly simple enough. Thank you.

here Peggy, go here and watch this video, it will allow you to better understand what is happening above, pay special attention at the beginning of the video in the cartoon where they show you going from Flow Limited breathing to Snore, it describes perfectly what I described above:

http://www.resmed.com/en-us/patients/ab ... 40x380.swf

Note: Also pay attention in the video where they show CPAP pressure being delivered via the nasal passage and observe what would happen if said delivery was from the mouth and the difference in leverage you have compared to delivering the splint pressure via the nasal cavity, the nasal cavity has greater leverage to "get under" the tongue as opposed to entering from the mouth.

This is why I say a nasal mask interface always offers better therapy over a full face mask, sleeping on your side as opposed to supine may also help.

pjwalman wrote:Wish I didn't have this sour taste in my mouth, but it's my own fault apparently for not being more savvy.

Not your fault, Peggy. The system was (and is) stacked against you, against all of us. Yeah, you coulda done better if you'd known more, but you did better than most in your situation. Ya dance with the devil, you're gonna get burned. (It's a heartless evil system, it is.)

The humidifier and the software are the smallest part of what you're dealing with. The good news is that you're learning how to better manage your therapy - and that unfortunately is a trial-and-error process, no two ways about it. Managing it effectively means a better life for you and those close to you. That's worth a lot more to you than the small costs involved.

My opinion is that it'll get better.

Regards,
Bill

Guess it's time to find another DME - preferably one who participates.

The good news - the experience you have gained is priceless and will take you sooo much further down the next road. You do have your own logbook, right?

Huh-oh. What is a log book? Whatever it is, I don't have one.