I need to stop chasing 0 AHI.

[JayC]

I strive for (although not *chase*) zero leaks.

I occassionally get zero AI....but since hypopnea and destats were more of the issues on the PSG....I am not surprised when I see the zero for AI. I have clusters of AI a few nights a week....some possibly positional if I end up on my back....some maybe unrelated to that. I feel REALLY crappy in the morning after they happen.

I can feel almost as crappy on nights when HI is 3 or 4. (That is high for me) Not sure whether possible desats or the arousals connected with that pattern are more connected to how poorly I feel on those nights.

On good nights, I am just banking good results to counter about 30 years of untreated SBD.....so, while I feel much better with therapy, and my therapy is working/progressing/being monitored, I am not a brand new woman.....yet.

My worst night on APAP is currently better than my usual nights prior to therapy.....so I'll hold on to that. I may hate my DME, but I have a great Sleep Doc....so I feel supported even though my trip through therapy is solo on a day to day basis.....(with the exception of all you good people, that is!!!!)

Warm regards,
J

[trackman]

After seeing your numbers and noticing most relies have come from folks with APAP machines, maybe I do need the APAP afterall

I have apap but seldom use it anymore. I feel I get just as good or better treatment with cpap. I try and keep my AI below 1 but am not always successful. I also find there is not always a direct correlation between the numbers and how I feel the next day. Sometimes I get into a deeper sleep which raises my numbers but makes me more rested than nights when my numbers are lower but I can tell I didn't sleep well/deep.
I have been at this two years and in spite of experimenting all over the place with my pressure I haven't found any pressure that is magic compared to the rest. I do restrict myself to side sleeping by wearing a backpack to bed that prevents me from rolling on my back. That seems to be the one variable that really makes a difference and sends my numbers up and causes an AI of a much longer duration. Hope this helps.

[KengEsq]

After seeing your numbers and noticing most replies have come from folks with APAP machines, maybe I do need the APAP afterall

I do restrict myself to side sleeping by wearing a backpack to bed that prevents me from rolling on my back. That seems to be the one variable that really makes a difference and sends my numbers up and causes an AI of a much longer duration. Hope this helps.

I know one problem I have is sleeping on my back but I would never be able to sleep wearing a backpack or anything else to keep me from sleeping on my back. I just figure that an APAP would adjust to changing events such as sleeping on my back, etc. Maybe not?

[fortomorrow]

I slept on my back last night and my AHI went up to a SHOCKING 1.7.

I feel the same as I always do this morning, except without the back pain I get when I sleep on my side.

[KengEsq]

I slept on my back last night and my AHI went up to a SHOCKING 1.7.

I feel the same as I always do this morning, except without the back pain I get when I sleep on my side.

Your poor thing you. If I could sleep in any position and get an AHI of 1.7 I would jump for joy. My AHI was 11.7 last night (beat you by exactly 10 points) but my leak was only 0.40 L/s so I thought I did well since my AI was only a 1.2. In fact, although my AHI numbers tend to be around 8+ I am happy my AI numbers tend to be less that 1. In any event my numbers are far better than the AHI of 47 I had the night of my sleep study. I have never been told what my AI number was for that test.

[rested gal]

I average about an 8.2 AHI with an AI less than 3. My doctor told me my numbers were "great" but I am not certain I believe him. I was only chasing an AHI of under 5 and have only achieved that about 3 or 4 times and was feeling bad about that and my numbers in general. After seeing your numbers and noticing most relies have come from folks with APAP machines, maybe I do need the APAP afterall.

I'm not so sure the difference between your numbers and the numbers you see others getting is really attributable to your being on "cpap" and some of them being on "apap." I think it's more a matter of what brand is being used.

And I don't mean that one brand is "better" than another. I mean that each manufacturer uses different definitions from each other, when it comes to defining, recording, and reporting "hypopneas." Any time I've used a ResMed machine (with everything about the set up exactly like the way I set up my Respironics or Puritan Bennett machines) I always see a higher HI (hypopnea index) score with the ResMed machine. Usually two to three times higher with the ResMed machine than the other brands.

Let me hasten to say, that doesn't mean ResMed is "better" at noticing hypopneas than the others are. Nor does it mean the others are "better" at preventing hypopneas than ResMed is. It's just a difference in what each manufacturer uses as the threshold for when a certain amount of flow limitation will be called "hypopnea." It's an arbitrary point put in place by each manufacturer in the design of their own machines. None of them are using the definition of "hypopnea" that is used in PSG sleep studies.

As I understand it, in a full PSG sleep study an event is not scored as a hypopnea unless there is also a certain percentage drop in oxygen level associated with the limited air flow. Or perhaps some are scored as hypopnea "with desat" and hypopnea "without desat." But anyway, our treatment machines are not "scoring" hypopneas the same way it would be done in a sleep lab PSG study.

When comparing my data results with a ResMed machine to data from my other brands (Respironics and Puritan Bennett) I mentally cut in half the HI reported from the ResMed machine. But that's just me, and the way I understand how it goes.

I feel equally good after a ResMed night resulting in AHI of 7.0 in which the AI (apnea index) was say, 0.2 and the HI (hypopnea index) was 6.8, as I do with another brand reporting same 0.2 for the apneas but just 3.4 for hypopneas. It's just a difference in arbitrary definition of "hypopnea" as far as I know.

I'd say, cut the ResMed "HI" in half and you'll see an AHI just as "nice to look at" as what others see from Respironics or Puritan Bennett machines.

Bottom line, of course, is as you say...

One final note, I feel much better and not at all tired since using my CPAP and I think the bottom line is that is what really matters.

Yep. That's what matters, and it's good to hear that you feel better!

An autopap might make a difference for you, Ken, but might not at all. Sounds like you're doing extremely well with "CPAP." An autopap is nice to have, of course, since it's like two machines in one. An autopap can always be set for just "cpap" mode if it turned out you slept better at one steady pressure.

[ozij]

I average about an 8.2 AHI with an AI less than 3. My doctor told me my numbers were "great" but I am not certain I believe him. I was only chasing an AHI of under 5 and have only achieved that about 3 or 4 times and was feeling bad about that and my numbers in general. After seeing your numbers and noticing most relies have come from folks with APAP machines, maybe I do need the APAP afterall. One final note, I feel much better and not at all tired since using my CPAP and I think the bottom line is that is what really matters.

Whenever I read a sentence like the one I emphasised in color, I pause, look at the type of equipment, and sure enough, it's a Resmed. Trust your doctor and the way you feel - Resmed's HI is always higher - because of the way it counts. The best way for you to get better numbers is to get another company's machine.... , but your therapy sounds like its great.
Relax and enjoy!
O.

[KengEsq]

Thanks for the comforting explanations. I had been told the ResMed reports higher numbers than most other machines and I was also told that its Leak numbers are off as well making me worry that I need a better fitting mask. Assuming ResMed reports a higher that accurate leak rate then I think my Zzz-Mask (full face) is just right for me. My machine reports a leak rate under 0.60 L/s and it is usually under 0.40.

My doctor explained to me that my inconsistent numbers should be expected because each night's sleep differs from all others. He also explained that sleeping on my back gives me the higher number and recommended sewing a tennis ball on the back of my PJs using a patch of cloth to keep me from turning onto my back - the trouble with that is I don't have any PJs. I was just thinking that an APAP machine might adjust for those nightly differences and give me better results whereas my CPAP cannot adjust if needed. The cost differential between a CPAP and an APAP is peanuts so I don't see any downside to changing to an APAP, especially if I can make it operate like a CPAP if I have any troubles.

Also, during my sleep test, apparently although I stopped breathing for an average of 18 seconds during each apnea event, my oxygen level did not drop in any significant way - likewise during my hyponea events. I would expect I would need to stop breathing for a long period of time to cause my oxygen level to drop (must be that my years of scuba diving and snorkeling have accustomed me to be able to hold my breath for a long time without ill effects).

I admit to loving my ResMed CPAP machine. It is quiet and performs well. It also gives me my numbers easily so I can keep track of my therapy and serves and an incentive to keep an accurate and detailed record for my own sense of how I am doing. Of course, I have never tried another make so I really cannot compare machines but I am afraid to desert my ResMed. I am willing to try the ResMed APAP machine since it appears to be almost identical to the one I currently use.

[georgepds]

I strive for (although not *chase*) zero leaks....

Newbie question.. I thought there was always a leak. It's not like there a valve to prevent leaks when you are not breathing out. There is a hole to let the air out (near the point of attachment of the tube to the mask) ,and the rate of flow is determined by the pressure drop and the resistance of that hole . Hence-- there is always a leak. The problem is when you open your mouth or knock the mask off your nose, then the much bigger hole gives a much bigger leak.

Am I missing something? Did the DME for get to give me the anti-leak valve;)

[JOYFUL56]

This was a very interesting thread - many thanks to all who shared!! I was diagnosed with apnea 10 years ago and have used cpap every night since then, but did not get a "smart" machine that let me track the nightly results until about 6 months ago. Very cool to get the feedback! It is a Resmed S8 Elite and my nightly AHI is usually around 3.5 (if I am not having major mask leak issues) and almost exclusively hypopneas. I had also wondered if the nirvana of a "0 AHI" as actually obtainable. My doctor reminded me that an AHI of 5.0 is the new threshold for diagnosing apnea (old threshold was 15 when I started) and said most people would have some sort of AHI index if hooked up to a monitor. Maybe he was just trying to making me feel better - but it made sense.

Joy

[rested gal]

I was also told that its Leak numbers are off as well

I've never heard that about ResMed's leak reporting.

And saying "off as well" sounds like still thinking their HI reporting is "off." It's really not a matter of "off" (which sounds like saying inaccurate. ResMed's "HI" (hypopnea index) numbers aren't "off" simply because the numbers differ from brand to brand. The higher HI reported for many people using ResMed machines is just a difference in what each manufacturer uses as a definition for hypopnea. Doesn't mean that one brand's recording and reporting is accurate and another's is not.

Assuming ResMed reports a higher that accurate leak rate

I really wouldn't assume that at all. As I said, I've never ever heard that about ResMed's leak reporting.

I'd think that if anything, it's probably easier to get an accurate leak rate reading from ResMed's method of leak reporting, since ResMed already accounts for the expected mask vent flow rate, depending on what mask you "dial in" to start with on the machine itself. Even if you use a different brand of mask, if you'll look at the charts for various ResMed masks to see what vent flow rate a ResMed brand mask gives at the pressure you'll be using, and then look at the chart for your own mask to see which ResMed mask (if any) your masks vent rate matches... then I'd choose the closest comparable vent rate to "dial in" on the machine's "mask setting."

If the ResMed suggested mask and your "other brand" mask happen to actually have the same exhaust vent flow rate, and your mask seals perfectly all night, you should see a leak rate of zero...the ideal with a ResMed machine. If you already know from comparing mask vent flow charts that your mask IS going to have a higher normal leak rate at the pressure you use, you can make that calculation yourself when looking at the reported leak rate. That's the kind of calculation people using other machines have to do anyway, since other brands report total leak INCLUDING whatever "normal leak" is coming from a mask's exhaust vent. So, ResMed makes that easier for you. They've already done that calculation. So a completely non-leaky night would come up with " 0 " leak on a ResMed machine.

then I think my Zzz-Mask (full face) is just right for me. My machine reports a leak rate under 0.60 L/s and it is usually under 0.40.

I haven't looked at the Zzz full face mask's flow rate chart, compared to ResMed's FF masks (Ultra Mirage FF, Quattro, Liberty) so can't comment on whether that 60 L/s is ok or not. Generally you want the leak rate when using a ResMed machine to be under 0.40 Liters per second. That probably doesn't matter so much when using their single pressure "cpap", but it might matter when using their "autopap." With all the calculations an autopap has to do about what pressure to use, a leak rate over the manufacturers' suggested "this is the max that's 'ok'", might confuse an autotitrating machine somewhat about what's going on....and what to do. Dunno.

That said, finding a mask that suits a person well enough and comfortably enough to actually sleep, is a major hurdle. You seem to have found that kind of mask for you, Ken. I'd be very loath to give up a mask that suited me well, just to try to achieve a lower leak rate (not that you're trying to do that.) But I don't think the ResMed machine is mis-reporting your leak rate. A leak rate hitting 60 L/s might not have any impact on treatment with the Elite cpap. Might, however, with an auto...no matter which brand of auto you choose. All brands of autopaps are more ticklish, so to speak, about what the flow is doing than cpap's are, I think.

[fortomorrow]

I haven't got a ResMed machine, so my experiences with leak rates and the Zzz FFM probably don't count for much, but for me it's less than the Breeze, usually about 26ish at 8cm.

[trackman]

I know one problem I have is sleeping on my back but I would never be able to sleep wearing a backpack or anything else to keep me from sleeping on my back. I just figure that an APAP would adjust to changing events such as sleeping on my back, etc. Maybe not?

I never thought I could sleep all night with a full face mask or air blowing in my face..but you adjust and get used to it over time. The same thing applies to a backpack or a waterpack or tennis balls sewn in your shirt. Whatever it takes to keep one off their back.

I have tried opening up my machine to 20 and I have never been able to eliminate the apneas I get on my back. It would probably take hurricane type winds.

[echo]

My doctor explained to me that my inconsistent numbers should be expected because each night's sleep differs from all others. He also explained that sleeping on my back gives me the higher number and recommended sewing a tennis ball on the back of my PJs using a patch of cloth to keep me from turning onto my back - the trouble with that is I don't have any PJs. I was just thinking that an APAP machine might adjust for those nightly differences and give me better results whereas my CPAP cannot adjust if needed. The cost differential between a CPAP and an APAP is peanuts so I don't see any downside to changing to an APAP, especially if I can make it operate like a CPAP if I have any troubles.

Ken - your doc is right. You might want to find some previous posts from Rooster - he had exceptionally high pressure needs when sleeping on his back, but when on his side he gets by just find with a much lower pressure. He's using a small backpack that he wears at night to keep from sliding back onto his back. A search for backpack and rooster should find you the right posts.
Many people find that an APAP is better for them than a CPAP, especially if they have very different pressure needs in REM and N-REM, or on their back vs. side. On the other hand, others cannot tolerate the pressure changes from the APAP and therefore must sleep with a fixed CPAP pressure.

Also, during my sleep test, apparently although I stopped breathing for an average of 18 seconds during each apnea event, my oxygen level did not drop in any significant way - likewise during my hyponea events. I would expect I would need to stop breathing for a long period of time to cause my oxygen level to drop (must be that my years of scuba diving and snorkeling have accustomed me to be able to hold my breath for a long time without ill effects).

I also never desaturated significantly (I had almost all hypopnea's), but my sleep has always been a complete wreck. The arousals will destroy your sleep (and health) just as much as the desaturations. In my case the doctor said the lack of significant desat was due to the fact that my brain "recovered from an event quickly", so I think that probably says more about your brain's ability to arouse you than the ability to hold your breath (although there might be something to what you say as well - I'm no doctor!! And I also dive though unfortunately not for the past couple of years ).

[JayC]

I'm still a newbie, and I would have asked the same question if I hadn't already read the answers!!

I have a ResMed machine, and a ResMed mask, and I have the machine set to the appropriate mask selection.....so the usual and necessary leak rate is taken into account by the time I see the data.

Zero, for me and my setup, means no leak over what is needed for mask to do the proper air exchange.

Does that help?

J

I strive for (although not *chase*) zero leaks....

Newbie question.. I thought there was always a leak. It's not like there a valve to prevent leaks when you are not breathing out. There is a hole to let the air out (near the point of attachment of the tube to the mask) ,and the rate of flow is determined by the pressure drop and the resistance of that hole . Hence-- there is always a leak. The problem is when you open your mouth or knock the mask off your nose, then the much bigger hole gives a much bigger leak.

Am I missing something? Did the DME for get to give me the anti-leak valve;)