Sleep lab couldent believe my `high pressure` !

[Chivalry]

well .....

after 3 months of differnt masks i finaly found 1 that is leak free!

BUT!... now i have a leak free mask, it seems my machine can now start to do an accurate job of measuring and counteracting my apneas....
Unfortunatly that seems to mean being up around 19-20 for the majority of the night while im asleep... lol

So took a trip to the drop in clinic yesterday and told my technician about it and got her to have a good look at the graphs using the rescan software.... and she basicly refused to believe that i could possibly need that ammount of pressure, to the point where she took my machine of me and gave me a replacement as the only way she could accept those kind of pressures was to believe my machine must be faulty
SO.... a new machine and 1 nights sleep later.... still up over 19 for my 95th percentile
She said that in the entire 9000 patients registerd with there clinic she hadnt heard of anyone even getting close to needing 19-20 before... i guess im just 1 huge walking apnea... lol

i do find it strange myself as well though... i could maybe understand it if i was massivly overweight like some of the other people i see at the clinic as i understand this has a big bearing on how bad the apnea is... but im only 15 stone (yeah.. i never said i WASNT overweight..lol) and have a bit of a tummy on me but im in no way huge...as im near 6ft...

Personaly i think that if i am on my back (which is where i allways tend to end up pretty soon after going to sleep) then i do indeed need a massive pressure to keep my apneas at bay...

Anyone else get up to the 19-20 pressure on a regular basis? or is it as uncommon as my technician says it is?

[rested gal]

There's always the possibility that your sleep study didn't come up with the correct pressure in the first place. Especially if you happened to NOT be on your back (supine) AND in REM (rapid eye movement) sleep a sufficient amount of time during the PSG (polysomnogram) titration.

I've read (somewhere, can't remember where) that a pressure of 10 has been shown statistically to hold the airway open nicely for most people. Of course that means there are people whose airway needs a lot more pressure than 10, and people who do fine with less than 10.

You may be one who falls into the the "more" camp. Or, you may not be -- it might be a good idea to think about your autopap's minimum pressure and EPR setting first.

What is the minimum pressure your ResMed S9 Autoset machine is set for, Chiv?

And do you have EPR turned on full time? If so, what EPR setting ( 1, 2, or 3 ) are you using?

Of course, there's always a slim chance that CompSAS... but, awww, let's not even go there yet.

after 3 months of differnt masks i finaly found 1 that is leak free!

That's good news, for sure!

[Chivalry]

well im in the UK... so we dont tend to get the level and depth of service for sleep apnea that ive seen people in the USA get..
We tend to get given an auto machine ( i got the s9 autoset) and its left wide open at pmin 4 and pmax 20 and then were kinda just told to let the machine do its thing and sort out where it needs to be set at itself...

In the last three months i have tinkerd around with the settings with advice from this forum and other... to the point i had my pmin up at 11 and pmax at 20... but was still getting a 95th percentile at above 19 most nights with the leak free mask....

[rested gal]

Gee... 19 ain't fun. Except maybe in age.

Well, maybe you could try this? Is there a way you could work out not turning onto your back for one night? If you can manage a way (perhaps wear a backpack to bed...I know, I know...sounds uncomfortable...but in the interests of being a lab rat for one night... ) to NOT sleep on your back at all for one night...

And then take a look at your machine's AHI data the next morning.

If you see a goodly drop in the AHI, maybe that would be a sign your airway collapses really badly when you're sleeping on your back.

Gotta be sure you really, really, reallllllly don't turn onto your back during the night -- if the "backpack" experiment is going to be of any use. And hope you can sleep at all with something that aggravating tied to your back!

[Chivalry]

well about 6 days ago... i do think i managed a night in my side..... at least i went to sleep like that... and woke up like that

For that night my pressure never went over 13........ i had 1 other night a couple months back with a similer result.... so im pretty sure its the case...

To be honest... im not to botherd about the 20 pressure,,,,, im asleep when it happens

As long as it stops my apnea thats athe main thing i spose...... unless theres any long term bad effects from running such a high pressure every night for so long.... ?

[rested gal]

well about 6 days ago... i do think i managed a night in my side..... at least i went to sleep like that... and woke up like that

For that night my pressure never went over 13........ i had 1 other night a couple months back with a similer result.... so im pretty sure its the case...

To be honest... im not to botherd about the 20 pressure,,,,, im asleep when it happens

As long as it stops my apnea thats athe main thing i spose...... unless theres any long term bad effects from running such a high pressure every night for so long.... ?

No long term bad effects that I know of, but then, I'm not a doctor.

So if 19 or 20 doesn't bother you, and your mask is holding up ok to it, and you're "asleep when it [ high pressure ]) happens" anyway ... well, it sounds like you're ok up there. In that case, I guess I'd set the minimum up even higher. Perhaps min at 15 or 16 if you can go to sleep with it like that. Or perhaps just try the straight CPAP route, setting a single pressure of 18 or 19, since you say 19 doesn't bother you.

I suppose you've already been keeping an eye on this, but I'll ask anyway... what has your S9 been reporting in the "central" category? If there haven't been many/any presumed centrals showing up in your data, then you and " 19 " really are getting along fine.

Have you had EPR turned on throughout all your previous raising-the-min experiments?

[Chivalry]

i had 3 centrals showing last night....... each around 15 secs..... i had 6 obstructives and 4 hypoapneas...

that gives an AHI of 2.1 ......... and an apnea index of 1.3.... 0.9 for osa and 0.4 for csa..

i hope thats well within acceptable..

[rested gal]

i had 3 centrals showing last night....... each around 15 secs..... i had 6 obstructives and 4 hypoapneas...

that gives an AHI of 2.1 ......... and an apnea index of 1.3.... 0.9 for osa and 0.4 for csa..

i hope thats well within acceptable..

I'm not a doctor, but I'd personally consider such a miniscule central apnea index to be insignificant. Especially up at the kind of stratospheric pressure you seem to thrive on, Chiv.

Your central apnea index of 0.4 is nothin', imho. As good as zero in my book. I wouldn't even worry about it if it were the other way 'round... with a "csa" being reported as 4.0.

All your numbers sure do look good. Feelin' better?

You could be a poster boy for handling one's own treatment well. Good job you've done for yourself!

[scrapper]

I was in a similar situation of pressures 19-20...........went back to the doc and he was unbelieving.......... He scheduled a titration, and they found 21 to be my best pressure. I moved to a bilevel, and have never slept so well!

[tschultz]

I am running in auto mode with pressure of 16 to 20, and over the night with treatment pressure tracking up or down in response to flow limitations., snoring, or apneas results in a median pressure of 17.7 and a 95 percentile pressure of 19.5. Over the past 14 days my AHI averages 2.7, my AI averages 1.8 with centrals at only 0.4 and obstructive apeans at 1.4.

The pressures drop correspondingly if I turn EPR off but at these higher pressures it does sure make breaking easier and I feel better in the mornings so I have it set to 2 and medium response. If I want to get decent number in CPAP mode I have to set my pressure to 19 or I start to see clusters of events to a higher degree than I do currently. My Rx pressure is 15 but that quite frankly does not work well for me regardless of what the sleep clinic's PSG data shows.

I switched over to auto when I found that after the first month on treatment I no longer slept in a single position with no moving, instead I now often awaken sleeping on my side. The changes in sleep position affect the required treatment pressure for me so the auto mode seems to work best overall.

My concern with getting my machine after my trial was indeed my need for such a high pressure and being at the upper end of what the CPAP/APAP machines are able to deliver. I discussed this with my RRT, we did discuss BiLevel however based on the fact that I was able to tolerate the higher pressure using the EPR and the good control of my OSA based on my actual data we both felt comfortable staying with the APAP machine. I need to lose "some" weight and we hope that my pressure may come down some, but that is not guaranteed so well just have to see.

I would say that just because they don't have anyone else at such a high pressure that does not mean there should be no one at such a high pressure.
I would also question that of the 9000 other people how many actually know their treatment is effective or optimized based on ongoing data?

If the higher pressure is working and not inducing centrals or causing other negative issues then I see nothing wrong with it.

[Chivalry]

how does high pressure induce central apneas?

[Pugsy]

how does high pressure induce central apneas?

I don't know if anyone knows exactly why some people get pressure induced centrals. It doesn't have to be a "high" pressure either. Some people will start getting centrals at pressures over as little as 8 cm.

So it isn't so much a "high" pressure that can cause pressure induced central as it is the fact that some people will have them pop up and others don't have any despite how high the pressure might be.

[tschultz]

From what I have found so far the issue of pressure induced centrals happens at pressures above 10cmH2O in only a small percentage of people. The fact that this does not seem to happen at pressures below 10cmH2O is one of the major reasons that the older auto algorithms did not increase pressure above 10 as a safety precaution as they were unable to determine the apnea cause.

The mechanism within the body is that the increased air in the lungs impedes the chemical receptors used to detect an increase in CO2 which indicates it is time to exhale. If the signal is never sent to the brain indicating that it is time to breath then it does not happen until some other mechanism kicks in or once increased CO2 levels are actually detected by the chemical receptors.

From what I was told if you don't start to see increased centrals at pressures of 12 or more then it is much more unlikely that higher pressures will cause a significant increase in centrals but you should watch for them if at all possible. I have been lucky and even at pressures of 20 I see no significant number of centrals, certainly nothing that is of a concern. A small number of centrals is normal for most people.

There still seems to be some question within the community of the accuracy of the detection and classification of centrals done by modern xPAP machines without additional information such as chest effort or other channels of data, where some feel the non-obstructive apneas should be simply classified as unknown and not truly centrals. The biggest thing here for our purposes however is not so much the semantics but rather if you are seeing mostly obstructive apneas and very few centrals or unknown then the higher pressure is not contributing to unwanted events.

[Chivalry]

Thanks for that... so 3 or 4 centrals showing each night isnt anything to panic over...... thats 1 less thing to worry about

[avi123]

Hi Chivalry, I could not understand your hi pressures already in your post from Jan 9, 2011 titled "New to apap, graphs ok?" The Statistics from that time showed zeros for apnea index, central, obstructive, and unknown. Only Hypo index was at 0.4 and so was the AHI. But the pressure that your S9 AutoSet rose to from 4 cm at 03:30 a. m. gradually to 20 cm at 06:00 a. m. Why? Also why the Events graph still showed 20 events per hour. Could it be b/c of your snoring, which peaked when you fell asleep first at 01:00 and next at 03:30?

I would do following:

1) Run the S9 on CPAP at 10 to 12 cm, EPR = off, and see what happens.

2) If the need for hi pressure continues, contact one of these specialists and ask what could be reasons:

West SD, Jones DR, Stradling JR.

Sleep Unit, Oxford Centre for Respiratory Medicine, Churchill Hospital, Headington, Oxford OX3 7LJ, UK. sophie@west66.freeserve.co.uk

You could email to Sophie your graphs and questions from your posts here and fom the UK forums.