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AHI measurement
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pstoloff Offline

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Posts: 4
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Machine: resmed s9 Elite
Mask Type: Nasal pillows
Mask Make & Model: resmed swift fx
Humidifier: resmed s9 H5i
CPAP Pressure: 15
CPAP Software: Not using software

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Sex: Male
Location: USA

Post: #1
AHI measurement
Hi all.

I awakened this morning and looked at the usage, mask fit and AHI data for my Resmed S9 machine with a nasal pillows mask. It showed 7.9 hours of use and an AHI of 1.1. Now fully awake, I kept my CPAP machine on, with my the nasal pillows mask on for an additional 20 minutes and re-read the display. The AHI had jumped to 1.4. Since I was fully awake, I think I would have noticed if I had stopped breathing. I did not. Is the increase in the AHI reasonable under these circumstances?
Additionally, the display showed a "frown" for mask fit. I did remove the mask with the machine still running (i.e., not turned off) twice during the night for about 2 to 3 minutes each time. How do such disruptions effect the AHI? I use the auto-start feature with the S9, which will stop the machine when I remove the mask, and restart it again when I replace it and it senses I'm breathing. Each time the machine is restarted under these circumstances, I run the test to determine if there is a mask leak. There was no leak indicated.


Thanks in advance any replies.
05-30-2013 10:12 AM
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trish6hundred Offline

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Posts: 6,450
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: AHI measurement
Hi pstoloff,
WELCOME! to the forum.!
Hang in there for answers to your questions and best of luck.

trish6hundred
05-30-2013 10:16 AM
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PaulaO2 Offline
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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: #3
RE: AHI measurement
It raised because our breathing during awake is different than our breathing during sleep. The machine does not know if you are awake or not.

Look at the data via ResScan or SleepyHead and see what changed during that time frame. A jump from 1.1 to 1.4 is not that large so it might have noted one possible event. Perhaps as you sat up and looked at the machine's screen, you held your breath just enough that it registered it as a hypopnea event.

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.
05-30-2013 03:26 PM
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zonk Offline

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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: #4
RE: AHI measurement
(05-30-2013 10:12 AM)pstoloff Wrote:  Additionally, the display showed a "frown" for mask fit. I did remove the mask with the machine still running (i.e., not turned off) twice during the night for about 2 to 3 minutes each time. How do such disruptions effect the AHI?
Thanks in advance any replies.
Events scored while wake are meaningless and be discarded for true AHI value. Also data is not reliable with leaks above 30 L/min

Mr Red Frowny face shows up if your 70% leak rate is greater than 24 L/min.
Mt Green smiley face shows up if your 70% leak rate is less than or equal to 24 L/min

As long as you are leaking at a rate of less than or equal to 24 L/min above your mask's intentional leak rate, ResMed do not believe there is a problem and Mr Green Smiley face shows up on the LCD "Sleep Quality" report

As for masks, everyone is different. I too sleep on my side and find chinstrap worn over the mask helps keeps the mask in place and the Activa LT cushion very flexible perfect for keeping a good seal with movement and the vents extremely quiet
05-30-2013 04:15 PM
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pstoloff Offline

Members

Posts: 4
Joined: Apr 2013

Machine: resmed s9 Elite
Mask Type: Nasal pillows
Mask Make & Model: resmed swift fx
Humidifier: resmed s9 H5i
CPAP Pressure: 15
CPAP Software: Not using software

Other Comments:

Sex: Male
Location: USA

Post: #5
RE: AHI measurement
(05-30-2013 03:26 PM)PaulaO2 Wrote:  It raised because our breathing during awake is different than our breathing during sleep. The machine does not know if you are awake or not.

Look at the data via ResScan or SleepyHead and see what changed during that time frame. A jump from 1.1 to 1.4 is not that large so it might have noted one possible event. Perhaps as you sat up and looked at the machine's screen, you held your breath just enough that it registered it as a hypopnea event.

How do mask leaks effect the AHI?
06-18-2013 08:53 AM
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SuperSleeper Offline

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Posts: 9,973
Joined: Feb 2012

Machine: PR System One REMstar Auto (DS560)
Mask Type: Nasal pillows
Mask Make & Model: ResMed Mirage Swift II
Humidifier: none
CPAP Pressure: 12.5 - 18.5 cmH20 (auto range)
CPAP Software: SleepyHead

Other Comments: Have diabetes Type II

Sex: Male
Location: Illinois, USA

Post: #6
RE: AHI measurement
(06-18-2013 08:53 AM)pstoloff Wrote:  How do mask leaks effect the AHI?

Without providing some sort of detailed technical info, the leaks affect AHI in that if the leaks are too high, you will not be getting the full amount of pressure needed to open up your airway (in order to stop apnea events). Thus AHI will generally rise the more leaks you have.

For instance, if you put several one-inch round holes in your CPAP tubing, that would induce so much air leakage that the pressure differential between the outside air and the air coming through the end of the hose into your mask will be next to nothing - and would have the same effect as having no pressure at all.

Modern CPAPs can account for some degree of leak and still provide effective therapy by making on-the-fly pressure adjustments to bring AHI into line (remaining below 5.0) - but once the leaks become major - no amount of CPAP auto-adjustments will help to lower AHI much.

SuperSleeper
Apnea Board Administrator
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.

06-18-2013 10:52 AM
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xwindowuser Offline

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Posts: 3
Joined: Jun 2013

Machine: Resmed S9 AutoSet
Mask Type: Nasal pillows
Mask Make & Model: Resmed
Humidifier: H5i
CPAP Pressure: 6-20
CPAP Software: Not using software

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Sex: Male
Location:

Post: #7
RE: AHI measurement
Does a yawn where your mouth is open and you breathing through your mouth, trigger an AHI event?
06-20-2013 12:14 AM
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Moriarty Offline

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Joined: Jul 2012

Machine: Respironics REMStar 50 Series Auto
Mask Type: Nasal pillows
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CPAP Pressure: 8.5-20 (average 9.4)
CPAP Software: SleepyHead

Other Comments: Image above is my CPAP machine...

Sex: Male
Location: Toowoomba - Qld - Australia

Post: #8
RE: AHI measurement
(06-20-2013 12:14 AM)xwindowuser Wrote:  Does a yawn where your mouth is open and you breathing through your mouth, trigger an AHI event?

Hello and welcome to the forum xwindowuser....

Since there is a minimum duration for an event to be flagged the question becomes...

Does the yawn last for more than ten seconds?

Even if it does it may not be seen as a Hypopnea nor an apnea... I think it would show in the .
(This post was last modified: 06-20-2013 01:36 AM by Moriarty.)
06-20-2013 01:32 AM
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