Question about Pressure Levels

[DiscoPistol]

Hi all,

I've had my APAP for over a year now and since I've had it I've always looked at the pressure in the morning (mainly because I'm sad but also becasue I've been losing weight and I was wondering if there would be a link between the two)

It started off at around 12 and a year later was hitting around 8.5/9.

A couple of weeks ago I hae my review (364 of 368 night and 8.04 hrs per night!) but I guess she reset the machine and now i'm getting pressure readings of 6.5/7 each morning.

I'm just curious as to how these machines work out the pressure really as I always assumed that it was based on the overnight reading but I'm thinking that it might be a tad more complicated than that!

Thanks

DP

[Tigers Fan]

Hi DP

My guess is that she reduced your max pressure so that you don't get gales when you have an event and thus your 90% pressure dropped.

TF

[DiscoPistol]

That makes sense!

Thanks for the answer.

[sheffgall]

I been a c-pap user now for 2ys. I can say i had my pressure taken down this week (i've been asking over a year since i lost the weight) has after losing lots of weight i thought that was the problem why it felt much more pressure then it was before maybe i dint need it or maybe my machine was playing up.

So after they look on my smart card for the results that still told them that at 15 it was still right for me.They told me weight has nothing to do with it? i was still needing it at the pressure at 15.But after a bit of begging them to lower it they did by one to 14 pressure.I have to send my card back in a month time to see if the 14 pressure is ok for me and im not having attacks if i am they put it back to 15, has they told me at 15 i was still having on average 5 attacks at night.I got to say even by turning my machine down by just one is loads better my mask don't flap around waking me up in the night like it was before and im getting a really good nights sleep that ive not had for ages.

So does weight really help with the pressure then, has this time now it been lowered it feels loads better. or was my sleep apnea nurse wrong or right.

[Tigers Fan]

Hi sheffgall

Some people lose weight and come off CPAP altogether; some people lose even more weight and it makes no difference to their CPAP. Weight does not improve OSA but it is not the only reason for OSA by a long list!

Sounds like you have OSA for other reason/s.

As you had an AHI of 5 at 15cm pressure, my guess is that you actually need to increse yo0ur pressure to, maybe, 16cm, rather than drop it to 14cm.

A leaking mask is not a good reason to drop pressure. A leaking mask is a pain in the proverbial and it needs fixing - you don't just drop a cog if you blow a head gasket, after all!

What sort of mask do you use? How old is it? How old the headgear/straps and how old the cushion/seal? Do you wash it regularly and do you wash your face before bed every night? How long is your hair/does the headgear slip on your hair?

Using info from your UPPP Surgery thread, can you tell us why you don't have your license back after two years on CPAP - it usually takes a few weeks. Are there reasons other than CPAP or are you plain not CPAP compliant (four hours a night)?

TF

[James @ Intus]

TF is probbaly right. If you don't find any detrimental effect in the day, it should be a good change.

As far as how they work, they are surprisingly clever yet also unsophisticated. Clever in that they monitor for a variety of events, like snoring, flow limitation, apnoea, hypopnoea etc. to try and guess what will happen next.

They are pretty dumb in that every night is a new night, back to square one. It won't care if you did 300 nights average of 8, it'll start at 4 again the next night. It won't be long for one manufacturer to break this habit and start making them self-learning little robots. Why start at 4 again when the data supports the notion that you fare better at 6 or 7?! That's probably the direction in which they'll go.

[Alleycat]

Weight definitely has some impact for the vast majority, if I recall correctly about 80% of cases are because of obesity but 20% of people with OSA are of healthy BMI. Where weight is the cause then losing weight definitely changes the pressure required as seen on an APAP. Unfortunately until one loses the weight its not going to be clear if the weight was the only cause. Some people can come off CPAP altogether with a sufficient weight loss but there's no guarantee. An AHI of 5 is fine. If your mask is having very bad leaks it can effect the delivered pressure so increase your events. It's better to have a couple of extra events per hour and be comfortable enough to keep it on all night than to have the pressure so high that you have an AHI of 1 for half the night.but then are so uncomfortable that you take it off for the rest of the night and thus go back to your diagnostic AHI.

[Tigers Fan]

"Sufficient weight loss" would be the answer - sufficient to ensure that it is lost from where it matters. Bums, tums, thighs, hips de dah may look better for being lighter but that will have no effect on OSA. Lose weight from your neck and you may - may - get an OSA moderation.

There is a curve around somewhere in the forum showing the amount of (waist/BMI) weight you have to lose to reduce the weight of your tongue by a gram.

TF

[sheffgall]

Hi sheffgall

Some people lose weight and come off CPAP altogether; some people lose even more weight and it makes no difference to their CPAP. Weight does not improve OSA but it is not the only reason for OSA by a long list!

Sounds like you have OSA for other reason/s.

As you had an AHI of 5 at 15cm pressure, my guess is that you actually need to increse yo0ur pressure to, maybe, 16cm, rather than drop it to 14cm.

A leaking mask is not a good reason to drop pressure. A leaking mask is a pain in the proverbial and it needs fixing - you don't just drop a cog if you blow a head gasket, after all!

What sort of mask do you use? How old is it? How old the headgear/straps and how old the cushion/seal? Do you wash it regularly and do you wash your face before bed every night? How long is your hair/does the headgear slip on your hair?

Using info from your UPPP Surgery thread, can you tell us why you don't have your license back after two years on CPAP - it usually takes a few weeks. Are there reasons other than CPAP or are you plain not CPAP compliant (four hours a night)?

TF

Hi Tigers Fan. They told me even thou i have on average 5 attacks at night that it is still is normal.But i found asking to dropping it that they did by one level to 14 is a lot better for me i am getting loads more sleep i feel more refreshed.I have to send my smart card back in a month time to see if it is OK if not they put it back to 15.I have been told i am using my machine right and is hardly no leakage to cause problems since i been using my new mask.But i will find out in a few weeks when i have used it for a month if this pressure is fine.But to me it feel loads better.My nasal cushions are not flapping about like they was before this is reason i also ask has well has it felt to much pressure also,but they says its showing hardly any leakage yet to me it was doing it a few times in the night.

I use to use a full face mask both gel and un gel but i dint like them.Over the year i have been using a Mirage Liberty mask that i love has i don't feel claustrophobic and i found it much easy to wear.This mask i have is nearly a week old has i have them changed along with my machine once a year has we only aloud one mask a year (don't know if its same everywhere else) unless the mask is not for you they will change it for another make.Also i change the nasal cushions regular i have 4 sets to last me over the year i have to ask for more if i need them. I do clean my face every morning and night and also my mask every morning with a antiseptic wipe and then twice a week i will wash it fully but its always clean.i do have long hair but since i been using this type of mask it shown less leakage then i had with the full face mask so i don't think my hair has anything to do with it?.


Has for my licence i am going to ask them when i take my daughter on the 10th august when she gets tested.Has i have still not hear anything about my licence back since they told me about the option of having a operation to get off the machine.I thought you had to get fully off the machine till you got it back.This is the reason i asked on the forum about the operation.Looks like i been told different things that getting me confused more about it all. Maybe because of the other masks i use to used before was not right for me so they did still make me feel tired the reason why?.

[Tigers Fan]

Hi sheffgal

Your AHI of 5 means five events an hour averaged over the night. Eight hours sleep with forty events gives an AHI of 5. You might go half the night without an evenyt and then have forty in the last four hours - the machine will record AHI = 5.

With AHI = 5, you should have had your license back ages ago. I'd chase the hospital as you suggest and call the DVLA if the hospital gives you no joy.

It's far from impossible that your pressure was too high at 15cm. If your AHI is lower than 5 when you get the results, that bears out your experience of sleeping better.

Good luck!

TF

[James @ Intus]

Note that some clinics won't even treat if AHI is 10 or 15! You could argue that is that's too little for them to consider a treatment-requiring disorder, then the DVLA shouldequally discard that as "normal". But I've spoken to plenty of people who feel horrible with an AHI of 10. These "standards" and guidelines based on averages just never seem to apply to real people. The average person doesn't exist, after all!

[sheffgall]

What do you mean by some clinic wont treat If AHI 10-15,Im getting more more confused now.Im i not suppose to be on a machine now because im having on average 5 attack a night wile i have my machine on, but when i dont i have over 60 attacks an hour wake up choking and snoring loud.

[Tigers Fan]

James means AHI 10 - 15 when untreated, without using CPAP.

In my early CPAP days, I was on AHI 12 with a machine for a while - relying on NHS clinic for pressure settings - and felt like death warmed up.

Your untreated 60 is definately in need of treatment. Your treated AHI of 5 shows how well yout treatment is.

TF

[James @ Intus]

What TF said.

So yes, in some areas of the country you can forget about treatment if you "only" clock 60-70 apnoeas a night, or 10 an hour.

This is also why many proposed CPAP alternatives aren't all that great. They claim say 70% reduction in AHI but if you go from 50 to 15, you still may feel utterly terrible. That's why you need something titratable, so you can continue tweaking until that AHI is at a level where you feel good. Not necessarily a level that has been assumed as good. One that works for your very individual you.

[Alleycat]

DVLA don't care too much about your AHI, its your ESS that is more important because it is the sleepiness that is the problem when driving. AHI and ESS have no correlation. Some people are very symptomatic with mild OSA and some have no symptoms despite severe OSA, and are o ly aware because they had a sleep study as part of a pre-op assessment.