How to reduce your AHI's for OSA [good results]

[dave21]

This is for anyone that are really trying hard to understand their AHI's and to try and reduce them. I need to put some disclaimers on here for people to read before attempting this as there's a number of very important points you need to understand

1. You need detailed access to your data
2. You need to be able to study and understand your graphs
3. This won't work for everyone but it will most likely work for Obstructive Apnea's/Hypopneas and might work for some Central Apneas
4. These tests were conducted on an APAP, it could work on a CPAP but not necessarily as well and I don't know about a BIPAP (possibly not)
5. This is not a miracle cure
6. Make changes to your machine at your own risk, I suggest you speak to a doctor first before even contemplating this
7. If your doctor or DME asks to read your data they will see differences in your machine configuration, so be prepared to explain it (and it could get you into trouble)
8. I am not a doctor
9. Make subtle changes, not big changes and document them.
10. Ensure you know what your original settings were so you can go back to them at any stage

Know your Titration pressure
Find out if you don't know what your titration pressure was, e.g. 10cm. This will help you work better with the graphs.

Study your graphs
It's very important to check your graphs. You can see what the pressure you are receiving on your machine throughout the night minute by minute, with an APAP you'll have a Min and a Max pressure that you can set as well as a RAMP pressure. You need to look at how many Apneas and Hypopneas you have per night. Look at the areas where you don't and check what your average pressure is. For me I had my ramp pressure set at 6cm as it's more comfortable to get to sleep with, the min pressure is 8cm and the max pressure is 20cm. This is too wide a gap but is how a lot of machines are configured. If you purchase your machine from a manufacturer then it is likely that your machine will not be configured to your settings.

Know how you sleep and improve it
If you suffer from Obstructive Apneas and know you sleep a lot on your back, force yourself to sleep on your side. Roll the duvet up behind you or prop a pillow up behind you to stop you rolling over. Also ensure you don't drink Alcohol as that can induce more Apneas, likewise over eating or a snack before bedtime can have the same effect. Also make sure as much as possible that your nasal pathways are clear. If you're congested uncongest yourself. If you can't uncongest yourself switch to a full face mask that will help in the comfort level. Also contain your leaks, try to reduce your mask leaks as much as possible. Lastly try to go to bed at regular times so your body clock also gets used to it.

Having the knowledge
So now you should see what your average pressure is on the graphs when you don't have any events and likewise what your pressure is when you do have events. You also know how to try and improve your sleeping patterns to get a better night sleep and suffer from less Obstructive Apneas.

If you look at the increase of pressure around your apneas, for me the pressure would go up to around 10.6 on average but sometimes could exceed this and raise to 12.5 in more severe events.

Once you know at what pressure you don't get 90% of apneas or hypopneas with and what your upper pressure limit raises to you can then start working out how to change your figures.

1. For the sake of argument, let's say there's only a difference of around 2cm then set your min pressure to the point where your lower Apneas/Hypopneas are, e.g. if your pressure is 10.6 to simplify things you can can round off to 10cm. The APAP's can cope and respond with a 0.6cm increase pretty easily and quickly.

2. You can leave the RAMP pressure as it is as this is only set for the first 30 mins of starting the machine for most machines.

3. Continue to make small tweaks until you think you are improving over continuous days and it's not one-offs.

How will this help?
1. Ensure that most of your lower Apneas and Hypopneas are resolved by giving you enough pressure to stop your upper airway to collapse.

2. Give you a small difference between your lower pressure and what will be required for the upper pressure to quickly adapt and reduce the time for the apneas and hyopneas to occur. This will then have the effect of stopping additional apneas and hyopneas but can also have the effect in reducing the amount of time you see an apnea for and possibly turn it into a hypopnea or remove it altogether.

For me tweaking the above settings carefully over several weeks has helped reduce my AHI further.

Here's what my events were like prior to making changes


Here's the results after gradually increasing the min pressure


Here's the results after further increasing the min pressure


Here's the results after further increasing the min pressure


On a really good night here's what my events now look like


*Note graphs are for an 8 hour period

I do not want to suggest everyone goes out and starts messing with their machines, you need to understand what changes you are making and why, the risks involved which could impact your health further or cause problems with your doctor/DME but what I will say for me is this has started to help me to reduce my events even further than I had imagined.

Some of you will be reading this and think that it's not rocket science and it's just common sense, and this may have been discussed on lots of other threads before and you are correct. Others will look at it and think why try to reduce your AHI by only 1 or 2 - is it really worth the effort? Others will also think why would you want to risk it? Making these changes are really up to you to decide, but I thought I'd show you some graphs as to how my graphs have gradually improved after making gradual tweaks.

Not every night is like the 4th or 5th graph, there are some nights where my AHI will go back up, e.g. sleeping on back (more prone to creating Obstructive Apneas), drinking alcohol, other Sleep Based Disorders like RLS, PLMD etc.

The other way to reduce your AHI for Obstructive Apneas is to lose weight (although it's not a 100% guaranteed way of reducing Apneas and can still occur).

Thanks
Dave

[Jersey Girl]

Dave,

I have always been on straight cpap - just started on Jan 8. I currently have a pressure of 8. So, if I wanted to do a little tweaking, based on your instructions, I would set my s8 Auto Set II to Apap with a low pressure of 8 and a high of 20 and then see what the pressure is at around the apneas? (I've never gone with apap - 2 settings, so just need a little clarification). How many nights do you recommend doing this for to really see the pattern?

Thanks,

Jersey Girl

[dave21]

Hi Jersey Girl!

Yes, for me to get my better graph results I would set the lower pressure to 9, and have a RAMP pressure also set to around 6 (or lower if you need it). If you have the data and can properly look over the data then you really want to get as much data as possible. Each night data changes whether you make changes or not, so something like a week would be best. Once I started to see improvements I made minor adjustments to tweak during a week.

Thanks
Dave

[DreamDiver]

I've been using nearly the same method for centrals, sans the ramp.
There seems to be a 'sweet spot' or a best minimum pressure in a standard bell curve.
Above or below, and you get more apneas/hypopneas.
It's interesting that we still end up self-titrating, even with an Auto, central or obstructive.
Excellent explanation dave21.

[dave21]

Thanks DreamDiver! I too find it interesting that we're self titrating even though we're on auto machines. Hopefully this thread might be able to help others that are starting out and want to achieve a new high score (or in our cases low score)

[dtsm]

Dave's post was really good and interesting reading. I just got back from my first follow-up with sleep center and had a fairly lengthy chat with the doc. I think he spent more time with me given I was 'armed' with all the detail graphs/print-outs, plus being 99.9% compliant since starting therapy back in early Jan.

Long story short, my chief complaint was that although my numbers were good, relatively flat leak line, decent Ai numbers, 8 hrs sleep each night, I didn't necessarily feel 'great'; what could I consider to seek improvement? He referred back to the original sleep study, when I got 5 hrs on the titration mask, had a relatively flat, very stable oximeter reading and woke up 'refreshed'. He compared it to the oximeter report I brought along and showed the difference - even though I was always above 93%, the fluctuations btw 93% to 98% were extensive. He said, try cpap (I'm now on apap) and see if oxygen saturation levels flattened out, like a flat leak line?

I'm curious what folks here think -- is that a good measure of effective treatment? I did switch to cpap last two nights, leak line flattened out considerably, oximeter shows no big changes, in fact it's more jagged than previous nights.

[KatieW]

dtsm, what were your settings on apap?--Min, Max, and EPR? And what is your pressure and EPR on cpap?

The oximeter readings are important, because oxygen desaturation means you are oxygen deprived, which affects heart rate and blood pressure.

[KatieW]

I've been using nearly the same method for centrals, sans the ramp.
There seems to be a 'sweet spot' or a best minimum pressure in a standard bell curve.
Above or below, and you get more apneas/hypopneas.
It's interesting that we still end up self-titrating, even with an Auto, central or obstructive.
Excellent explanation dave21.

DreamDiver, re Centrals, have you found that lowering the pressure helps? I'm wondering, because in Sleep Apnea--Phantom of the Night (page 70) it says:

"Because central sleep apnea may result from a low level of carbon dioxide, it is possible to treat central sleep apnea simply by raising the level of carbon dioxide. This can be done by encouraging a small amount of rebreathing of carbon dioxide by using CPAP, but at a relatively low pressure. This results in a slightly increased level of carbon dioxide in the blood during the period of wakefulness before sleep. Thus, when the patient falls asleep and sensitivity to carbon dioxide declines, the transition to sleep is smoother because the carbon dioxide is already closer to the level that will trigger breathing during sleep. This shortens the episode of central apnea and often lets sleep onset occur without arousal. Ultimately, less central apnea occurs.

However, if the CPAP pressure is too high, this actually lowers the carbon dioxide level in the awake patient and can precipitate even more central apneas. In patients with pure central sleep apnea syndrome only low levels of CPAP are applied and if central apenas become more numerous, the pressure is lowered."

This book is dated 2002, so there may be new research. And masks may have changed, to limit this rebreathing of carbon dioxide. But if the above is true, I wonder if using ramp at a lower pressure would help?

[DreamDiver]

I've been using nearly the same method for centrals, sans the ramp.
There seems to be a 'sweet spot' or a best minimum pressure in a standard bell curve.
Above or below, and you get more apneas/hypopneas.
It's interesting that we still end up self-titrating, even with an Auto, central or obstructive.
Excellent explanation dave21.

DreamDiver, re Centrals, have you found that lowering the pressure helps? I'm wondering, because in Sleep Apnea--Phantom of the Night (page 70) it says:

"Because central sleep apnea may result from a low level of carbon dioxide, it is possible to treat central sleep apnea simply by raising the level of carbon dioxide. This can be done by encouraging a small amount of rebreathing of carbon dioxide by using CPAP, but at a relatively low pressure. This results in a slightly increased level of carbon dioxide in the blood during the period of wakefulness before sleep. Thus, when the patient falls asleep and sensitivity to carbon dioxide declines, the transition to sleep is smoother because the carbon dioxide is already closer to the level that will trigger breathing during sleep. This shortens the episode of central apnea and often lets sleep onset occur without arousal. Ultimately, less central apnea occurs.

However, if the CPAP pressure is too high, this actually lowers the carbon dioxide level in the awake patient and can precipitate even more central apneas. In patients with pure central sleep apnea syndrome only low levels of CPAP are applied and if central apenas become more numerous, the pressure is lowered."

This book is dated 2002, so there may be new research. And masks may have changed, to limit this rebreathing of carbon dioxide. But if the above is true, I wonder if using ramp at a lower pressure would help?

KatieW,
You've hit on something very important. I'll need to learn more about this. Remembering the gap in data from a few nights back, and seeing the oximetry being fairly flat during that time made me wonder if all I really need is to wear the mask. The zzz is a full-face, and it has a fairly large cavity and an anti-asphyxia valve. It may conserve just enough CO2 to effect the preferred environment.

Unfortunately, I have no way to measure apneas under that circumstance. However, the oximeter could be set to alarm at a set level. I'm scared to try it because I hate the headache I get when I don't use the machine. It would be nice if the machine could record during ramp.

I'm talking to a new sleep doc today to get some answers. This is great information, I really appreciate it. The better armed with info, the better questions I can ask. Wish me luck!

[KatieW]

Thanks Dave, for the excellent summary. Do you use EPR? The reason I ask, is in the previous ResMed's, the minimum pressure needed to be raised to compensate for EPR. Have you found if this is also the case with the S9?

This is from one of many threads on this topic by RestedGal:

"In ResMed machines, when using EPR, the pressure stays down throughout the exhalation and during the pause at the end of exhalation. That lower EPR pressure might (or might not) be enough to hold the airway well and truly open in order to get an inhalation started again. If you turn on EPR in the ResMed machine, I'd raise the minimum pressure one cm for every "one cm of drop" you had set EPR to give.

EPR in ResMed and Respironics do not work the same way. In a Respironics machine, when using C-Flex or A-Flex, the therapeutic pressure comes back in before the exhalation is finished."



I am currently using cpap mode, at 10.6 cm H2O, with EPR of 2. The Statistics Report shows: Median: 10.6, 95th Percentile 10.6, Maximum 10.6. And the Detailed Graph shows a straight line at 10.6

With the S8 at 10.6 cm, and EPR of 2, the Statistics Report showed: Median: 9, 95th Percentile = blank, Maximum 10.6. And the Detailed Report showed a squiggly line, for when EPR was used or suspended (in response to reduction in flow).

Just pondering here, is this an actual change in how the cpap and EPR is functioning, or a change in how it's reported?

[DreamDiver]

KatieW
I've placed a hold for the book at my local library through inter-library loan.
I'll be reading it soon enough. Thanks.

[dtsm]

dtsm, what were your settings on apap?--Min, Max, and EPR? And what is your pressure and EPR on cpap?

The oximeter readings are important, because oxygen desaturation means you are oxygen deprived, which affects heart rate and blood pressure.

Most recent apap was 9.8 to 13, my average 9.8, 95th percentile 10.6 and max 11.4, EPR at 1
I set cpap first night to 10, EPR 1, last night raised to 10.8 EPR 1. I am aware of differences with ResMed and EPR settings. Will slowly tweak cpap - maybe up to 11.8 this weekend with EPR 1. Or turn off EPR completely.

As rested gal and others have always preached, really need to give each new tweak at least 5-7 days before changing.

[JohnBFisher]

... I'm curious what folks here think -- is that a good measure of effective treatment? I did switch to cpap last two nights, leak line flattened out considerably, oximeter shows no big changes, in fact it's more jagged than previous nights.
...

Do you see how your apneas seem to cluster together? It is VERY possible (though imposssible to tell with just the efficacy data) that this is when you entered REM sleep. Why do I say that? Well, most people have apneas that occur during REM sleep. The atonia during REM sleep can cause the airway to collapse, leading to obstructive sleep apnea.

During REM, the activity of the brain's neurons is quite similar to that during waking hours, but the body is paralyzed due to atonia; for this reason, the REM-sleep stage may be called paradoxical sleep.

From: Myers, David (2004). Psychology (7th ed.). New York: Worth Publishers. p. 268. ISBN 0716785951. http://books.google.com/books?id=oYuBwP ... 1&pg=PA268. Retrieved 2010-01-09.

If I were in your shoes, I would see if there was something I could do, such as the ball on the back of the T Shirt, to avoid sleeping on my back. It might indicate during REM sleep you need MORE pressure (if you can tolerate it) rather than less. But if staying off your back does improve the situation, it might indicate you need to talk with your sleep specialist.

[dave21]

Thanks Dave, for the excellent summary. Do you use EPR? The reason I ask, is in the previous ResMed's, the minimum pressure needed to be raised to compensate for EPR. Have you found if this is also the case with the S9?

This is from one of many threads on this topic by RestedGal:

"In ResMed machines, when using EPR, the pressure stays down throughout the exhalation and during the pause at the end of exhalation. That lower EPR pressure might (or might not) be enough to hold the airway well and truly open in order to get an inhalation started again. If you turn on EPR in the ResMed machine, I'd raise the minimum pressure one cm for every "one cm of drop" you had set EPR to give.

EPR in ResMed and Respironics do not work the same way. In a Respironics machine, when using C-Flex or A-Flex, the therapeutic pressure comes back in before the exhalation is finished."

Hi Katie, I do use EPR (although I don't really need it for the Activa mask but it does help me if I put on the Swift FT. I haven't carried out any tests yet with and without EPR, I'll see if I can do that over the next couple of weeks.

[Melinda]

I don't understand why apnea events still occur, and frequently, while using xpap.
I too get clustered events. Shouldn't they disappear all together with the use of an xpap machine?
If I set my machine to near it's lowest flow setting(for max too), would that be a good way of seeing how many apnea events I get without the use of xpap? I'd like to compare just how many events my current machine is stopping on average.