Post Reply 
Pressure differance between prescribed and actual
Author Message
tonksss Offline

Members

Posts: 6
Joined: May 2014

Machine: ResMed S9 Elite
Mask Type: Nasal mask
Mask Make & Model: Respironics Nasal wisp
Humidifier: ResMed H5i
CPAP Pressure: 9 and 3 EPR
CPAP Software: ResScan SleepyHead

Other Comments:

Sex: Male
Location:

Post: #1
Pressure differance between prescribed and actual
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
(This post was last modified: 05-25-2014 11:45 AM by tonksss.)
05-25-2014 11:41 AM
Find all posts by this user Post Reply Quote this message in a reply

Donate to Apnea Board
trish6hundred Offline

Advisory Members

Posts: 6,453
Joined: May 2012

Machine: Resmed S9 AutoSet for Her
Mask Type: Full face mask
Mask Make & Model: Fisher & Paykel Simplus
Humidifier: H5i Heated Humidifier
CPAP Pressure: 10 - 7-20 Cm H2O
CPAP Software: Not using software

Other Comments: I started CPAP in 2008. Totally blind since birth.

Sex: Female
Location: Missouri, USA

Post: #2
RE: Pressure differance between prescribed and actual
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
05-25-2014 12:13 PM
Find all posts by this user Post Reply Quote this message in a reply
Peter_C Offline

Advisory Members

Posts: 1,308
Joined: Sep 2013

Machine: System One DS960HS
Mask Type: Full face mask
Mask Make & Model: Mirage Quattro "MED"
Humidifier: Attached
CPAP Pressure: Auto mode-script is:15/3/3
CPAP Software: EncoreBasic Other Software

Other Comments: Severe obstructive sleep apnea 1999/Just got an ASV machine

Sex: Male
Location: Akron, Ohio USA

Post: #3
RE: Pressure differance between prescribed and actual
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."
05-25-2014 01:52 PM
Find all posts by this user Post Reply Quote this message in a reply

Donate to Apnea Board
PaulaO2 Offline
Wiki Editor
Moderators

Posts: 8,068
Joined: Feb 2012

Machine: S9 Autoset
Mask Type: Full face mask
Mask Make & Model: F&P Simplus
Humidifier: H5i
CPAP Pressure: 14-20
CPAP Software: SleepyHead

Other Comments: Ehlers-Danlos Syndrome, Hypermobility Type; chronic sarcasm

Sex: Undisclosed
Location: western NC, USA

Post: #4
RE: Pressure differance between prescribed and actual
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.
05-25-2014 04:02 PM
Find all posts by this user Post Reply Quote this message in a reply
tonksss Offline

Members

Posts: 6
Joined: May 2014

Machine: ResMed S9 Elite
Mask Type: Nasal mask
Mask Make & Model: Respironics Nasal wisp
Humidifier: ResMed H5i
CPAP Pressure: 9 and 3 EPR
CPAP Software: ResScan SleepyHead

Other Comments:

Sex: Male
Location:

Post: #5
RE: Pressure differance between prescribed and actual
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.
(This post was last modified: 05-25-2014 04:38 PM by tonksss.)
05-25-2014 04:37 PM
Find all posts by this user Post Reply Quote this message in a reply

Donate to Apnea Board
zonk Offline

Advisory Members

Posts: 7,908
Joined: Feb 2012

Machine: A10 AutoSet
Mask Type: Nasal mask
Mask Make & Model: Activa LT
Humidifier: Integrated /ClimateLineAir
CPAP Pressure: 9/13
CPAP Software: ResScan

Other Comments: CPAP since Nov 2010

Sex: Male
Location: Australia

Post: #6
RE: Pressure differance between prescribed and actual
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
05-25-2014 05:02 PM
Find all posts by this user Post Reply Quote this message in a reply
tonksss Offline

Members

Posts: 6
Joined: May 2014

Machine: ResMed S9 Elite
Mask Type: Nasal mask
Mask Make & Model: Respironics Nasal wisp
Humidifier: ResMed H5i
CPAP Pressure: 9 and 3 EPR
CPAP Software: ResScan SleepyHead

Other Comments:

Sex: Male
Location:

Post: #7
RE: Pressure differance between prescribed and actual
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
05-25-2014 05:13 PM
Find all posts by this user Post Reply Quote this message in a reply

Donate to Apnea Board
vsheline Online

Advisory Members

Posts: 1,915
Joined: Jul 2012

Machine: S9 VPAP Adapt (USA Model# 36007, not better 36037 or 36067)
Mask Type: Full face mask
Mask Make & Model: F10 or SimPlus w/ 2Liners. MirageQuatro & Gecko gel pad
Humidifier: H5i
CPAP Pressure: 15 EPAP, PS 5-10
CPAP Software: ResScan

Other Comments: Marfan Syndrome, chronic bradycardia, occasional Cheyne-Stokes Respiration

Sex: Male
Location: California, USA

Post: #8
RE: Pressure differance between prescribed and actual
(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.
(This post was last modified: 05-25-2014 11:54 PM by vsheline.)
05-25-2014 11:36 PM
Find all posts by this user Post Reply Quote this message in a reply
tonksss Offline

Members

Posts: 6
Joined: May 2014

Machine: ResMed S9 Elite
Mask Type: Nasal mask
Mask Make & Model: Respironics Nasal wisp
Humidifier: ResMed H5i
CPAP Pressure: 9 and 3 EPR
CPAP Software: ResScan SleepyHead

Other Comments:

Sex: Male
Location:

Post: #9
RE: Pressure differance between prescribed and actual
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
05-26-2014 01:48 PM
Find all posts by this user Post Reply Quote this message in a reply

Donate to Apnea Board
Sleepster Offline
Wiki Editor
Moderators

Posts: 4,995
Joined: Feb 2012

Machine: ResMed AirCurve10 VAuto
Mask Type: Full face mask
Mask Make & Model: F&P Simplus
Humidifier: HumidAir and SlimLine Hose
CPAP Pressure: MaxI 13.6 | MinE 5.2 | PS 4.4
CPAP Software: ResScan SleepyHead

Other Comments: Diagnosed Nov 2011. Conquered aerophagia.

Sex: Male
Location: Houston, Texas

Post: #10
RE: Pressure differance between prescribed and actual
(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.
05-26-2014 10:03 PM
Find all posts by this user Post Reply Quote this message in a reply
Post Reply 


Possibly Related Threads...
Thread: Author Replies: Views: Last Post
  Which disturbs sleep most? High Pressure or Changing Pressure Rcgop 7 1,285 11-10-2016 07:37 PM
Last Post: Sleep2Snore
  Lower max pressure affecting pressure increases Rcgop 9 721 07-17-2016 07:03 PM
Last Post: green wings
  I pressure/E pressure - cause/cure - on CAs Rcgop 1 536 06-17-2016 08:47 PM
Last Post: richb
  SleepyHead Question: machine settings on Daily Sidebar don't match actual settings Kris the Crone 6 381 06-15-2016 04:37 PM
Last Post: Kris the Crone
  Help, DME is asking why I enabled Auto when I was prescribed a set pressure cotrik2001 33 2,596 05-13-2016 01:28 PM
Last Post: Sleepster
Gross treatment pressure higher than the setting pressure debby2242 24 2,018 04-03-2016 01:34 PM
Last Post: sonicboom
  LOW AHI vs actual REAL quality sleep waydavis 28 3,961 08-28-2015 03:37 PM
Last Post: PaytonA

Forum Jump:

Who's Online (Complete List)