What is a high pressure considered?

[AnotherGuest]

What is considered a "high Pressure"? I ask becuase I don't know if I need an auto cpap or bipap. My pressures are 4-19, with most of my events seeming normal around 10-13. Thanks!

[Guest]

I don't know if there is a definition for high pressure. I'm inclined to think it's anything over 13.
Are you saying you are currently using an auto cpap with a pressure range of 4-19? Do you have difficulty exhaling against the pressure? If not, then an auto will be sufficient. Does the auto you're using have an exhalation relief feature? Is the exhalation relief feature turned on?

[Goofproof]

Most people are sucessfully treated at 10 cm avg, however, that doesn't mean anything, you need the pressure required to keep your airway open so you can breath.

Your 4 to 19 cm number doesn't make much sense, to sounds like someone gave you a APAP and didn't know what you needed or how to find out. I am using a CPAP with C-flex at 15.5 with no problem breathing against it.

If your needed pressure is above 17 cm BPAP is easier on you and it can go to 30 cm, Heaven Forbid! APAP and CPAP only goes to 20 cm.

[AnotherGuest]

I had few events at 6, but then they kept increasing the pressure until 19. From few events at 6, it increased to an average of anything between 5-15 events at 10+.

Can your body actually have more events for some reason with a higher than needed pressure?

[AnotherGuest]

Thought it might help to actually post my #'s:

Pressure Events
4 -- 0.0
5 -- 15.0
6 -- 0.9
7 -- 15.1
8 -- 11.7
9 -- 10.8
10 - 4.6
11 - 0
12 - 9.1
13 - 4.2
14 - 9.1
15 - 7.5
(No 16?)
17 - 9.3
18 - 10.7
19 - 3.9
20 - 0

Can anyone make sense out of these? It seems really sporatic and no real pattern.

[Guest]

It would not be unusual for the sleep lab to keep increasing your pressure until they saw diminishing returns so they could zero in on the best pressure. What did the sleep lab determine was your correct titrated pressure? That should be the pressure where the fewest events occurred.

Yes, it is possible that a pressure that is too high can induce centrals, but it isn't common. In addition, pressure needs can fluctuate depending on body position; when you're on your back it typically requires the most pressure to treat your apneas.

[Guest]

Are your numbers from your titration study?

[AnotherGuest]

Yes, these are the #'s from my titration study. They wrote an APAP Rx with setting of 6-20. I do sleep alot on my back and my side, but I have mild scoliosis so sleeping on my side hurts.

[Guest]

First, I have seen rested gal suggest this for others with questions on their sleep study, so I will pass it along to you. You could post your sleep study report in the "Sleep Studies" forum at this site:

http://www.apneasupport.org/forum-4.html

deltadave, an RRT, RPSGT and manager of an accredited sleep lab, has interpreted a lot of studies and may be able to help you with yours. The more charts, tables and information you can provide from your study, the better.

Second, they prescribed an APAP for you. Have you used it yet and do you have the software to monitor the results?

[Selena]

Hi, is it just possible that there was a misunderstanding - 99% of Cpap machines, auto or otherwise, are originally calibrated to work from 4 to 20 cms, and then your MD or techs, etc. figure out what the best starting pressure (within that range) should be for you to try out, e.g. 8, and if you have c-flex, 8 to say 15, both of which may get readjusted in future depending on how things progress, but the machine is still fixed to function between 4 and 20 cm, regardless of where YOU tell it to start you at any given time. In other words, if you don't program to start you off at 7, and go no higher than 11, it will still internally jack itself up from 4, not 2 or 5, etc. and go no higher than 20 ever.

[ozij]

Hi, is it just possible that there was a misunderstanding -

Since I find much of Selena's post confusing, I'll try to sort it out

99% of Cpap machines, auto or otherwise, are originally calibrated to work from 4 to 20 cms,

Those are the pressures the machines are capable of delivering. There are some that can deliver higher pressure too.

and then your MD or techs, etc. figure out what the best starting pressure (within that range) should be for you to try out, e.g. 8

,

In the days before self adjuststing, automatic machines (APAPs), a titration study ended with a recommendation of one set pressure for a person to use on their CPAP (Continuous Positive Air Pressure) machine. This number was found by gently and gradualy changing the pressure during the night, till the pressure was found at which you had no events. This gradual, carefully watched change till the perfect level is found, is what "titration" means.

Once self adjusting machines were invented, there was no longer an apriori need for one set pressure. In theory, and sometime in practice, a self adjusting machine can adjust its pressure to your needs at a certain moment, heighten it if it finds indications the your airways are closing up, lower it of it sees you breathe smoothly for a while. Self adjusting - aka automatic machines are very good for people whose pressure needs vary depending - among others - on their sleeping positions. The shortcut name for these machines is APAP. They can range in pressure from very low (usually 4) to very high (usually 20). The machine's lowest and highest pressure can be set manually (via keys or softer) thereby limiting the range according to the patient's comfort and needs. Some sleep better with a broader range, some with a narrower range, and some sleep better with no pressure changes at all that is, with their APAP set to function as a CPAP.

In addition to CPAPs and APAP, there are machines built to give higher pressure on inspiration, and much lower pressure on expiration. The inspiration pressure might be defined as a constant 14, the expiration as a constant 7 - each of them is constant. These are bi-level machines they are more expensive than either APAP or CPAP - and are necessary for people who cannot exhale against their prescribed inhalation pressure, or those who suffer from gas - aerophagia - as the result of their therapy.

To make CPAP therapy easier, straigt machines also have a ramp option. This lets the patient set a lower starting pressure, and a time during which the pressure will rise gradually to the prescribed pressure. Its meant to let the patient get used to breathing against the incoming pressure gradually, and - hopefully - fall asleep before pressure has reached the top. During ramp time, the pressure rises, on its own,gradually, and consistently. Some APAPs have a ramp option, some don't. Most users stop using the ramp after the first few weeks.

Another attempt to make things easier for patients is a kind exhalation relief in which the machine lowers pressure slightly when it senses the patient has started to exhale. This is not bi-level therapy, and different companies give this feature different names. Respironics calls it C-flex, and has it in both automatic and straight (non-automatic) machines. Resmed has it on one of its automatic machines, but it will work only when that machine is in non-automatic mode (go figure). These are " comfort amenities" - very usesful and necessary for some, not at all necessary for others.

O.

[Guest]

your titration numbers explain why they sent you home with a autopap, they are all over the board, most likely your not hitting REM sleep and so they couldn't establish a proper titration pressure.

But after seeing your numbers, I would not have left it wide open. I would have set the machine to a range of 6-10, allow you to use it for several days to a week then review the reports to see if there is any pressure flattening indicating a pressure increase is needed then adjust from there. If you needed a higher pressure then the reports would show that a straight flat line at 10cm for long periods of time.

You may be so sleep deprived that you have trouble staying in REM, then the pain you mention from the scoliosis can be an additional reason you cannot stay in REM.

I suggest seeing your doctor about addressing the back pain. Do you take anything for the pain now? What happens if you take like an Aleve about 1hr before bed? Do you see any improvement with sleep?

Most people find the default 4cm pressure to be way too low, you may end up being stuffy or starving for air.

[Selena]

Ozij, isn't it funny? I found your long explanation even more confusing.

[ozij]

Selena, try to digest it pragraph by paragaph.

C-flex has nothing do with the ability go give the machine a range of pressures.

Automatic machines can be given a pressure range. They do not all have C-flex.

Once you're clear about those terms, you might find other things less confusing.


O.

[Goofproof]

Thanks ozij! You nailed it, I was going to try but I was too tired, you did a great job of it. I couldn't add a thing.