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

Pressure differance between prescribed and actual
#1
I am still new to the "Hose" but soon found that The oldtimers here are correct in saying to monitor your own therapy.
To that end, I am getting very good reports (ResScan and Sleepyhead) but have a question. My prescribed pressure is 9 but when I download and view my reports, both programs have a max and min pressure during sleep that is constantly between 5-7. Is this because the machine "Sees" that I don't need 9 to alleviate apneas.
My AHI is always well below 2 and I feel 100% better. Am I to understand that the "9" is a maximum and not necessarily the minimum? Sorry if this has been covered already!
If you change masks and want to check pressures, what pressure are you checking while wearing the mask? If you "Plug" the hose, I'm am sure you will be at prescribed pressure. I hope this makes sense as I need to try another mask soon.
Remember - "If It Ain't Broke, DON"T Fix It!
Thinking-about
Post Reply Post Reply
#2
Hi tonksss,
WELCOME! to the forum.!
It sounds like you are off to a good start, it's great to hear that you are feeling so much better..
Hang in there for more answers to your question and best of luck to you with your CPAP therapy.
trish6hundred
Post Reply Post Reply
#3
Hello and welcome to the forum. You do not say if you are on a fixed pressure machine or an autoset machine. And what your script said your machine was to be set at.

Off-hand (just guessing based on what you said), you *might* be on an autoset with a min pressure and a max pressure. If that is the case, the machine will never use the max pressure unless and until you actually need it. It will give you the min pressure whether you need it or not, but the max pressure setting is more of a do not go over this pressure kind of thing.

As far as masks are concerned, feel free to use whatever style and brand mask you want. While there are settings for mask type/model, this is not a critical area - mostly just make sure the style it is set on is correct (nasal, pillows, or FFM). Finding a mask that is both comfortable and leak free is the challenge.
*I* am not a DOCTOR or any type of Health Care Professional.  My thoughts/suggestions/ideas are strictly only my opinions.

"Only two defining forces have ever offered to die for you. Jesus Christ and the American Soldier. One died for your Soul, the other for your Freedom."
Post Reply Post Reply


#4
The machine will know if a person is wearing the mask vs the hose was simply blocked.

The way I understand how an autoPAP works is:

You fall asleep. The machine increases the pressure to where it feels the least resistance as you breathe.

You fall further asleep. The throat muscles, which are voluntary, start to relax further, and you enter a hypopnea event. Meaning the airway narrows. The machine does not immediately increase pressure, but waits to see if the pressure it has holds the event from getting worse. If it does, then it increases pressure to prevent the next hypopnea event from happening. If it does not and the hypopnea narrows further, then it increases the pressure but only slightly. Once the event ends, it increases the pressure again to prevent the next one from happening.

You roll onto your back. Now gravity has entered into play and a full obstructive event happens. The airway is blocked. The machine sends a series of pulses to confirm. Yes, it is blocked. Like before, it waits to see if the pressure build up is enough. If it is, then it increases the pressure again. If it is not, it increases the pressure to end the event.

Time wise, we're looking at mere seconds. An event is not recorded as an event unless it lasts longer than 10 seconds. We can look at our pressure graph and see that it often looks like ocean waves as it tests to see if it can drop down yet or not. We can also see that it increases after an event.

I could be wrong in how this works so don't take it to the bank!
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
#5
I'm sorry, I didn't clarify enough. This is a S9 Elite machine. It is constant (Fixed)pressure. That is why I am baffled. Any help is greatly appreciated. Script is 9 and I never see the pressure close to that. The machine IS set to 9 and Epr 3.
Post Reply Post Reply
#6
Yes, SleepHead (SH) shows EPAP when using EPR
For example if pressure set at 12 and EPR 3
SH shows ... pressure 12 and EPAP 9
Also on my AutoSet, SH shows two pressure graphs ... pressure and mask pressure

ResScan does not show such thing, S9 Elite is not APAP or bi level machines


Post Reply Post Reply


#7
Average Pressure 6.38 6.38
Min Pressure 5.12 5.12
Max Pressure 7.66 7.66
90% Pressure 7.38 7.38
Average EPAP 5.99 5.98
Min EPAP 5.12 5.12
Max EPAP 6.00 6.00
Thanks for the response Zonk. These are the numbers that I see in SleepyHead. What am I looking at Huhsign The EPAP doesn't bother me. The others do. As soon as I think that I understand something...LOL
Thanks for the help all.
Remember - "If It Ain't Broke, DON"T Fix It!
Thinking-about
Post Reply Post Reply
#8
(05-25-2014, 11:41 AM)tonksss Wrote: I am getting very good reports (ResScan and Sleepyhead) but have a question. My prescribed pressure is 9 but when I download and view my reports, both programs have a max and min pressure during sleep that is constantly between 5-7. Is this because the machine "Sees" that I don't need 9 to alleviate apneas.
My AHI is always well below 2 and I feel 100% better. Am I to understand that the "9" is a maximum and not necessarily the minimum? Sorry if this has been covered already!
If you change masks and want to check pressures, what pressure are you checking while wearing the mask? If you "Plug" the hose, I'm am sure you will be at prescribed pressure. I hope this makes sense as I need to try another mask soon.

Hi tonksss, welcome to the forum!

Twenty-five times a second your machine measures the pressure and the rate of airflow into the hose.

If the machine has been properly set for correct hose type then it knows the correct hose diameter and length. The pressure dropped/lost across the humidifier and hose will be a function of the rate of airflow and the type of hose.

The machine will calculate an estimate for the mask pressure, based on the measured pressure at the machine, the measured rate of airflow into the hose, and the hose length and diameter. The estimated mask pressure (which is the therapy pressure seen by us users) is what ResScan will display/report in the High Rate Pressure plot.

If there is a huge leak (such as if the mask is off) then the machine will not be able to reach its target mask pressure.

During inhalation ResScan should be showing the pressure quickly and smoothly rising to around 9, and during exhalation the pressure should be quickly and smoothly dropping to around 6,

If you cough or breath out hard the mask pressure may go higher than 9.

If you inhale quickly and hard, or if there is a sudden or large leak, the pressure may drop lower than 6.

(05-25-2014, 05:13 PM)tonksss Wrote: Average Pressure 6.38 6.38
Min Pressure 5.12 5.12
Max Pressure 7.66 7.66
90% Pressure 7.38 7.38
Average EPAP 5.99 5.98
Min EPAP 5.12 5.12
Max EPAP 6.00 6.00
Thanks for the response Zonk. These are the numbers that I see in SleepyHead. What am I looking at Huhsign The EPAP doesn't bother me. The others do. As soon as I think that I understand something...LOL
Thanks for the help all.

The EPAP numbers look right. But the average, 95% and max Pressure (Pressure = IPAP) do seem way too low.

SleepyHead has been going through rapid revisions recently, and perhaps you are using the newest version which I think has some recently-introduced bugs. A new and better release will be available within a week or so, I think.

In the mean time, since you have a ResMed machine, ResScan can be used. I suggest double checking the data using ResScan to see if the 95% and max pressures look more reasonable using ResScan.

If upon double check, ResScan confirms these low average, 95% and max pressures, then either your Max Pressure setting is lower than prescribed, or huge Leaking is occurring all the time, or perhaps the machine is not operating correctly and will need to be checked by the Durable Medical Equipment (DME) provider who supplied the machine.

If the mask type is wrong in the machine's settings, the reported value of Leak will be somewhat off, but the delivered mask pressure would not be affected.

By the way, what are your Leak numbers?

By the way, might be good idea to also check the total machine hours to verify you were given a new machine.

Take care,
--- Vaughn


.
Membership in the Advisory Member group should not be understood as in any way implying medical expertise or qualification for advising Sleep Apnea patients concerning their treatment. The Advisory Member group provides advice and suggestions to Apnea Board administrators and staff on matters concerning Apnea Board operation and administrative policies - not on matters concerning treatment for Sleep Apnea. I think it is now too late to change the name of the group but I think Voting Member group would perhaps have been a more descriptive name for the group.
Post Reply Post Reply
#9
Thanks for input Vsheline. Your assessment of SleepyHead I think is spot on. ResScan shows the pressure as prescribed. Too much thought I guess. My leak rate showed <2.0 L/min last night. My leak rate has never been any problem just dry mouth. Chin straps are just a necessary evil when you can't keep your mouth shut! (Don't tell my wife I said that. She thinks CPAP is the greatest thing since Apple Pie because it pretty well cured my snoring). My sinuses are taking a beating with the wisp though. That is why the concern about pressures when changing masks.

Again, Thanks to all
Remember - "If It Ain't Broke, DON"T Fix It!
Thinking-about
Post Reply Post Reply


#10
(05-25-2014, 11:41 AM)tonksss Wrote: My prescribed pressure is 9 but when I download and view my reports, both programs have a max and min pressure during sleep that is constantly between 5-7.

In both SleepyHead and ResScan? That's weird. Maybe the pressure wasn't set to 9 when the machine was set up.

Your machine should also display the pressure as you're using it. Look at the on screen display and see if it's 9.0 cm H2O.

Since your AHI is so low, and you feel so good, I wouldn't make any adjustments to the machine.

Sleepster
Apnea Board Moderator
www.ApneaBoard.com


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


Possibly Related Threads...
Thread Author Replies Views Last Post
  Isn't Resmed's Expiratory Pressure Relief really Inspiratory Pressure Support?? Reznik 116 2,534 11-27-2017, 07:28 PM
Last Post: Reznik
  With a face mask pressure is about 8.5. With a nasal pillow pressure was 20 at one po brojohn1611 10 564 11-04-2017, 03:05 AM
Last Post: James2017
  Autoset 90 percentile pressure vs. Titration study pressure CDNHoser 12 434 10-19-2017, 09:02 PM
Last Post: Sleepster
  Pressure at altitude vs. pressure at lower elevations...? S.L. Ping Beauty 19 471 10-17-2017, 09:36 PM
Last Post: PaulaO2
  [Equipment] Viscious cycle of increased pressure -> more leak -> response of more pressure 3mp0w3r 5 305 09-16-2017, 09:04 AM
Last Post: OpalRose
  Apnea More Severe; Prescribed Pressure Decreased fwg1947 18 732 07-17-2017, 09:00 AM
Last Post: fwg1947
  ResMed S10 Auto set Measured vs Actual Pressure happyguardian 5 471 06-26-2017, 08:36 PM
Last Post: bonjour

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.