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

ASV - At last
#11
Hi,
I followed instructions Asjb and I thank you because night three was great again. I did get a lot of blowouts so I am changing to the Simplus.
AHI 2.2 - UAs 0.4 / Hypos 1.8 I am really pleased with the numbers but can someone remind me what the adjustments for Hypopneas are?
Thanks again,
Don
-------------------------------------------------------------------

Our greatest weakness lies in giving up. The most certain way to succeed is always to try just one more time.
Thomas A. Edison



Post Reply Post Reply
#12
(03-25-2016, 07:43 AM)DonC Wrote: Hi,
I followed instructions Asjb and I thank you because night three was great again...... I am really pleased with the numbers but can someone remind me what the adjustments for Hypopneas are?
Thanks again,
Don

Hello Don,


Hypopnoeas - as for apnoeas, i.e. PS adjustments for central hypopnoeas on looking at detail of flow wave, and EPAP adjustments if detail shows the hypos were obstructive in nature (i.e. followed by one or more deep 'recovery' breaths).

best wishes, asjb

..................................................................................................
My current settings: Auto-ASV. EPAP 11-14. PS 3-10
Post Reply Post Reply
#13
(03-26-2016, 05:03 AM)Asjb Wrote:
(03-25-2016, 07:43 AM)DonC Wrote: Hi,
I followed instructions Asjb and I thank you because night three was great again...... I am really pleased with the numbers but can someone remind me what the adjustments for Hypopneas are?
Thanks again,
Don
Hypopnoeas - as for apnoeas, i.e. PS adjustments for central hypopnoeas on looking at detail of flow wave, and EPAP adjustments if detail shows the hypos were obstructive in nature (i.e. followed by one or more deep 'recovery' breaths).

I think hypopneas generally are obstructive in nature. The ASV machine increases PS immediately there is a diminution in airflow, so if the event is central it is likely to be suppressed before it gets started. If it doesn't respond for 10 seconds or more it's likely to be obstructive, in which case raising the EPAP is the indicated approach. From the clinician manual: Central sleep apnoea detection (CSAD) is not active in ASVAuto and ASV modes. The ASV algorithm eliminates central apnoeas. Therefore, any apnoeas reported by the device will be obstructive or indicative of a closed airway.
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


#14
(03-26-2016, 05:41 AM)DeepBreathing Wrote:
(03-26-2016, 05:03 AM)Asjb Wrote:
(03-25-2016, 07:43 AM)DonC Wrote: Hi,
I followed instructions Asjb and I thank you because night three was great again...... I am really pleased with the numbers but can someone remind me what the adjustments for Hypopneas are?
Thanks again,
Don
Hypopnoeas - as for apnoeas, i.e. PS adjustments for central hypopnoeas on looking at detail of flow wave, and EPAP adjustments if detail shows the hypos were obstructive in nature (i.e. followed by one or more deep 'recovery' breaths).

I think hypopneas generally are obstructive in nature. The ASV machine increases PS immediately there is a diminution in airflow, so if the event is central it is likely to be suppressed before it gets started. If it doesn't respond for 10 seconds or more it's likely to be obstructive, in which case raising the EPAP is the indicated approach. From the clinician manual: Central sleep apnoea detection (CSAD) is not active in ASVAuto and ASV modes. The ASV algorithm eliminates central apnoeas. Therefore, any apnoeas reported by the device will be obstructive or indicative of a closed airway.

Thanks for that info. I should have checked the manual!

Post Reply Post Reply
#15
(03-24-2016, 12:51 PM)DonC Wrote: I used Auto CPAP only before the jump to ASV and the settings were 8 to 15. You said "your current settings will of course give you a max IPAP of 24 (max EPAP 14, max PS of 10) which is quite a 'shock to the system'". I thought these were separate pressures and happened when breathing in or breathing out.

IPAP, the pressure during inhalation, is EPAP plus PS.

(03-24-2016, 03:34 PM)Asjb Wrote: My understanding ... is that a pressure support max setting of 10 should be enough to 'breathe for you' when you have central apnoeas, and so get rid of those. The PS will also resolve hypopnoeas.

If we have normal lungs, during a prevented central apnea (during what would have become a central apnea if we would have been using a regular CPAP or APAP or BiPAP machine) a Max PS setting of 10 will typically be adequate to keep us breathing very close to our normal amount of air while the machine is doing for us all the work of breathing.

A large Max PS like 10 will also prevent other central events like (in absence of an ASV machine, what would have become) central hypopneas and Periodic Breathing.

Some ASV users have terrible problems with aerophagia which impell them to limit their treatment pressures, or they may have a doctor who unfortunately does not understand how ASV therapy works and prescribes an inappropriately low setting for Max PS. If the Max PS setting is quite low, such as less than around 8, the ASV machine may be able to eliminate mild Periodic Breathing but may be unable to completely eliminate central apneas, perhaps resulting in central apneas being converted into central hypopneas.

A high setting for Max PS would tend to elminate all central events and would tend to help at least a little toward preventing obstructive hypopneas, but obstructive hypopneas and even obstructive apneas may still occur.

Rather than raising Max PS, instead, raising the EPAP settings is what most helps to prevent obstructive events. On a ResMed ASV machine, EPAP cannot be set higher than 15.

Quote:... you also had a noticeable obstructive component in your test night and to treat those you need an adequate EPAP. I think you've previously alluded to the fact that your obstructives were dealt with pretty well with APAP 8-15? Have I got that right? If so, you may well eventually need an ASV-auto EPAP setting of something similar to 8-15.

That is my understanding, also.

Quote:But if you go immediately now to 'theoretically perfect' settings that will mean you having an IPAP max of 25 (i.e. Max EPAP plus PS), and that is quite a jump from your APAP max of 15 and will take a while to get used to, and will likely give you mask leak and adjustment challenges initially.

Right.

(03-26-2016, 05:41 AM)DeepBreathing Wrote: From the clinician manual: Central sleep apnoea detection (CSAD) is not active in ASVAuto and ASV modes. The ASV algorithm eliminates central apnoeas. Therefore, any apnoeas reported by the device will be obstructive or indicative of a closed airway.

Of course, here RedMed is presupposing that Max PS has been set high enough to completely prevent central apnea events.

Regarding what our Min PS setting should be, if we have normal lungs I suggest adjusting Min PS to at least 2 and using a recording pulse oximeter to monitor our average (not minimum) SpO2, targeting an average SpO2 between 94 and 96, not counting the short dips during obstructive events.

But if we have COPD, an SpO2 of 94 may be way too high and may lead to excessively high CO2 in the blood. If we have COPD, I think a safer target range for SpO2 would be between 89 to 91.

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
#16
This posting was put on the forum before reading vshelines post - If I contradict anything I apologize

Thanks again everybody,
So basically the machine stops OAs and CAs being registered but UAs and Hypopneas are really a form of OAs.
So last night, day number three on ASV my AHI was 2.0 / Hypops 1.82 and UAs 0.18 - This was over 5.5 hours so I had 10 Hypopneas and 1 (yes one) UA.7 events had gulps of air after them and the others looked pretty even.
The interesting thing is that every single Hypopnea only lasted for 10 seconds exactly. The UA was 15 seconds giving me a total of 1 min 55 seconds in apnea through the whole session. Pretty good for a guy who was in Apnea for over 30 minutes in my first sleep study.
I am pretty close to getting under an AHI of 1.0 or even lower. I used the Simplus and had no major leaks with maybe 2 blowouts that I know about.
I thank you all again for your help.
The settings I came up with were ASV auto. EPAP 6 - 10 and PS 4 to 10.
No Ramp, Tube temperature 86 F and Humidity setting of 3. Average pressure 13.3 - Min 6.06 - Max 19.86. There were no events after the maximum and the 90% pressure was 15.6. I was really comfortable with only the two sessions of pressure that ended in blowouts.
Tonight is the night to get under one. What changes would you make if any? By the way, I feel good so am going out tonight without being pushed on my 38th Anniversary.
Thanks again
Don
-------------------------------------------------------------------

Our greatest weakness lies in giving up. The most certain way to succeed is always to try just one more time.
Thomas A. Edison



Post Reply Post Reply


#17
(03-26-2016, 02:04 PM)DonC Wrote: So basically the machine stops OAs and CAs being registered but UAs and Hypopneas are really a form of OAs.

It is not that the ResMed ASV algorithm stops OAs, it's that it does not take the time to attempt to distinguish the type of apnea, so these are listed as unclassified apneas.

The Forced Oscillation Technique (FOT) used by ResMed to distinguish between OA and CA typically takes 10 seconds (after a 4 second delay to allow inhalation to start normally, the FOT runs for at least 6 seconds to allow an accurate measurement of airway openness), which means perhaps a 10 second CA would need to be allowed if distinguishing OA from CA were to be done, and apparently it has been judged to be better just to proceed directly with treating the apnea.

Although in ASV modes ResMed does not classify the type of apneas which are occurring, presumably all apneas will be OAs because a Max PS setting of 5 (which on a ResMed ASV machine is the lowest allowable setting for Max PS) will presumably be high enough to at least convert all CAs into central hypopneas, which, of course, would no longer be apneas.

Quote:What changes would you make if any? By the way, I feel good so am going out tonight without being pushed on my 38th Anniversary.

First, congratulations on your 38th!

Regarding changes, as Asjb and DB have suggested, I also suggest gradually raising the EPAP settings to eliminate the UAs and Hypops.

In particular, I suggest that the Max EPAP be very gradually walked higher until it is set 1 or more higher than the 90% or 95% value used for EPAP. (The 90 percentile EPAP pressure was the EPAP the machine was at or lower than for at least 90% of the time. It is also the EPAP the machine was at or higher than for at least 10% of the time.)

And I suggest that the Min EPAP be gradually walked up to around 1 lower than the median value for EPAP. (However, a few APAP users have reported they feel best when their Min EPAP is set only slightly less than their 90% or 95% EPAP pressure, and I assume the same thing would be true if these had been ASV users.)

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
#18
Congratulations on your success.
I hope your dogs have recovered from their trauma, too.
I am very curious as to how the DME reacted to your calm discussion regarding the used machine. Have they agreed to replace it with new? Or give you a significant discount for the 20% of its life that was gone before it was presented to you?
4 years from now you may be presented with unwelcome choices if things are not corrected now.
Post Reply Post Reply
#19
I had a bit of a set back last night. I forgot to put the Chip back into the computer and ended up with the machine telling me that I had an AHI of 5.8 but when I put the chip back in and then took it and put it into Sleepyhead it agreed with the machine on the hours but gave me an AHI of 1.18.
I did open a thread on the Software Page to question this so to get back to this thread.
I will follow your advice on the EPAP Vsheline and keep trying for better numbers until I get the elusive zero.
As for the story with the machine; The wife and the dogs have recovered but I doubt if the manager of the office has. I was told twice or more when I picked it up that it was a new machine, the tech I was dealing with just wasn't telling the truth.
When I spoke to the manager they said that; when we had been chasing the delivery of the machine the week before I took delivery I was told that the machine was in and that I could pick it up. When I reminded them about this they said that they had never actually told me that this was a new machine and that proved that they had never lied.
After about 30 minutes of me responding to this they agreed to replace the loaner with a new machine but would not put it in writing. I was told that they were not allowed to and they held firm on this???? So I haven't got the new one yet but I am pretty sure I will. I am not going to tell the whole story until they let me down and then I am going to tell everybody and I mean everybody.
I don't think they like me at the moment.
Don
-------------------------------------------------------------------

Our greatest weakness lies in giving up. The most certain way to succeed is always to try just one more time.
Thomas A. Edison



Post Reply Post Reply


#20
Don, when I got my machine the tech removed it from a sealed Resmed carton in front of my eyes and demonstrated it had zero hours. I think that should be standard procedure when purchasing a new machine.
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


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.