Hello Guest, Welcome to Apnea Board !
As a guest, you are limited to certain areas of the board and there are some features you can't use.
To post a message, you must create a free account using a valid email address.

or Create an Account


New Posts   Today's Posts

What do pressures mean
#1
I was wondering if anyone can help me under the meaning of pressure. I am on APAP therapy with a pressure of 6 - 15 cm. I understand that it starts out as 6 and then increases as much to 15 as needed.

How does the machine determine how to increase the pressure? What happens if I get to my max pressure throughout the night? I recently got to 15 last night and I think I was on it for at 1 hour and then again later on in the night for a little while as well. I was in the 11-14 range for most of the night. I don't mind the higher pressure, actually is more helpful. I know that the highest APAP can go is 20. I don't want to change any settings as of now since I haven't been on therapy a week yet.

Any help, suggestions would be helpful. Thanks!

Inky1
Post Reply Post Reply
#2
What happens is the machine sends out tiny pulses of air that act as kind of an echo. If there is no echo, then airway is open. If there is an echo, then airway is closing (hypopnea) or is closed (obstructive apnea event). When the machine senses a hypopnea starting, it increases the pressure in the attempt to stop the event from happening. But sometimes an OA event happens without the hypopnea "warning" so the machine waits until the event is over and increases the pressure to what is needed to maintain the airway at that point. If the airway is maintained, it then slowly decreases, sending out pulses, detecting if the airway is closing again. Rinse, repeat.

So a CPAP does not exactly stop an OA event, but rather tries to prevent the next one from happening.

We set our machine pressure minimum to a high enough point so the machine doesn't need to take a running start. For example, if your median pressure and/or 95% minimum stays at about 8, then 6 or 7 is a good minimum.

We set the maximum to a high enough point it can take care of the events but not so high the machine has the chance to "run away". For example, if your highest pressure and/or 95% maximum pressure is 14, then 15 or 16 would be about right.

Once those settings are established, you would then continue to watch the data for several weeks. If at 6 you see you never drop below 7, then it would make sense to increase the minimum to 7. And if you see that at 15 you are maxing out that pressure quite often, you may want to increase it to perhaps just 16 then again, watch the data for a while.

A single night's data is rather worthless. There are too many variables that go into a good or bad night's sleep to say "this pressure setting does not work". That is why we tell everyone to TAKE NOTES of changes and any event that may affect your sleep while doing pressure changes. And then to let it sit and to watch for trends.

PaulaO2
Apnea Board Moderator
www.ApneaBoard.com


Breathe deeply and count to zen.

INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.




Post Reply Post Reply
#3
Your machine responds to flow limitations (airway partially compromised) and snores. If you look at a SleepyHead screenshot you can see the correlation quite clearly -- this is part of a report from my machine:

[Image: FLs_zpsft7qigay.jpg]

I don't have snores in my snore graph but if you do, you'll see your snore line also corresponds to pressure changes.

Snores and flow limitations are treated by the machine as precursors to apnea events. As Paula said, apneas can and do occur in the absence of those precursors, which is why it's pretty difficult to eliminate all apnea and hypopnea events all the time.

Post Reply Post Reply


#4
Just adding to what's already been said - if your machine goes to the maximum and stays there, it's an indication that your maximum might not be high enough. However, as Paula said, you should keep an eye on things for a while and watch for trends. If it keeps on sitting at the maximum over many nights, then the max probably needs to be increased.
DeepBreathing
Apnea Board Moderator
www.ApneaBoard.com


Bed

INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
Post Reply Post Reply
#5
(02-16-2016, 06:00 AM)DeepBreathing Wrote: Just adding to what's already been said - if your machine goes to the maximum and stays there, it's an indication that your maximum might not be high enough.
More likely the case, but in my experience with the A10 AutoSet, the machine tend to respond aggressively to flow limitation (wasn't an issue for me with S9 AutoSet) and put the pressure sky high and that disrupt my beauty sleep
Its a question for me, do I want all all FL dealt with higher pressure or some FL and lower pressure
[Image: images?q=tbn:ANd9GcR8ketk4wqq-Znc4NPdUxQ...okkmLkjNqZ]

Sleep-well
Post Reply Post Reply
#6
Wow! I really like and appreciate all the knowledge that is within you guys in this wonderful forum!

Thanks for this great information that is so important for newbie like me.

Have a nice day!

I-love-Apnea-Board
Post Reply Post Reply


#7
Thank you for all the advice and comments. Since I'm a newbie I am trying to understand as much of this as possible. I don't plan on making any changes to pressure as of now, just wanted to know how this device is supposed to work and help me.

Thanks again!

Inky1
Post Reply Post Reply
#8
(02-16-2016, 03:58 AM)kaiasgram Wrote: Your machine responds to flow limitations (airway partially compromised) and snores. If you look at a SleepyHead screenshot you can see the correlation quite clearly -- this is part of a report from my machine:

[Image: FLs_zpsft7qigay.jpg]

I don't have snores in my snore graph but if you do, you'll see your snore line also corresponds to pressure changes.

Snores and flow limitations are treated by the machine as precursors to apnea events. As Paula said, apneas can and do occur in the absence of those precursors, which is why it's pretty difficult to eliminate all apnea and hypopnea events all the time.
OK... Your Pressure Graph is NOTHING at all like mine.
I have a single trace called "Pressure."
One presumes that this is because you are using an S9 VPAP Auto and I have an AirSense 10 Auto set. Is that correct?
Or is there some SleepyHead setting which I have not found yet which allows multiple plots.

Naturally, the related question is - What is "IPAP and "EPAP"
The other difference, to be expected, I think, is the fact that your graph appears "smoothed" while mine is quite eratic.

   

So much for using the attachment feature on the forums Smile
Bill Magill
Retired computing and networking professional
(ARPAnet, Unix and Mac OSX)
"People assume that time is a strict progression of cause to effect,
but actually — from a non-linear, non-subjective viewpoint —
it's more like a big ball of wibbly-wobbly... timey-wimey... stuff."
The Doctor
Post Reply Post Reply
#9
(02-16-2016, 12:44 PM)whmagill Wrote: OK... Your Pressure Graph is NOTHING at all like mine.
I have a single trace called "Pressure."
One presumes that this is because you are using an S9 VPAP Auto and I have an AirSense 10 Auto set. Is that correct?

Or is there some SleepyHead setting which I have not found yet which allows multiple plots.

The dual lines are a product of the CPAP model (BiPAP/ASV). The "regular" A10's and S9's usually have a single pressure graph.

(02-16-2016, 12:44 PM)whmagill Wrote: Naturally, the related question is - What is "IPAP and "EPAP"
The other difference, to be expected, I think, is the fact that your graph appears "smoothed" while mine is quite eratic.

The "I" in IPAP stands for Inhale and the "E" in EPAP stands for Exhale. In SleepyHead, the Detailed section on the Daily screen will list a Pressure and an EPAP. If you are using EPR these two values will reflect the EPR difference, otherwise they will have the same values.
Post Reply Post Reply


#10
(02-16-2016, 12:44 PM)whmagill Wrote: OK... Your Pressure Graph is NOTHING at all like mine.
If you use EPR on your Autoset you should also have two pressure lines, one for IPAP and one for EPAP (reflecting your EPR setting of 1, 2 or 3).

Also, you posted your Flow Rate graph below your Pressure graph, not your Flow Limit graph like I have in mine. Check out your Flow Limit graph instead and you'll see the correlation with pressure.

Post Reply Post Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Question on masks that will handle higher pressures like 27 nanook683 13 1,084 09-21-2016, 07:14 AM
Last Post: nanook683
  Help (Resetting Pressures) Linda57 9 616 08-19-2016, 06:57 PM
Last Post: icyura10
  95%/ max pressures rising - wondering why? Carbon 7 821 05-08-2016, 04:53 PM
Last Post: zonk
  Help please with fine-tuning Resmed ASV pressures Asjb 9 802 04-29-2016, 04:48 AM
Last Post: Asjb
  [Pressure] Danger Involved - Changing your own CPAP pressures SuperSleeper 99 30,463 04-12-2016, 04:51 PM
Last Post: FrankNichols
  [Treatment] Cant seem to adjust pressures Cookie 24 2,428 10-31-2015, 07:05 AM
Last Post: Cookie
  Make System One ASV constant pressures regbeach 3 673 10-18-2015, 08:53 PM
Last Post: Sleepster

Forum Jump:

New Posts   Today's Posts




About Apnea Board

Apnea Board is an educational web site designed to empower Sleep Apnea patients.

For any more information, please use our contact form.