Lower AHI. Suggestions?

[Chuck Connors]

I finally discovered this website within the past 10 days. Since then, I've learned that I had a high leakage rate. Fixed that with a head strap in order to keep my mouth shut during the night. My AHI dropped considerably, but is still hovering around 3.5 to 5.1. Most people would agree that's within a good range. However, I would like to learn about the other factors involved in achieving a lower AHI. Aside from leakage, what are the other factors involved in lowering the AHI? Adjustment in the pressure, I would assume. Thanks. -Chuck-

[Pugsy]

Yes, usually a minor adjustment upward in pressure BUT....that AHI...you need to evaluate all the components and not just the overall AHI.

The overall AHI on the S9 machines has the central index added in....Centrals we don't treat with pressure increases with this particular machine. If the AHI is predominately Central..a pressure increase is not indicated and might actually make them worse (rare but it could happen) but if zero to minimal Central index then yeah a little bump in pressure might help a bit.

So...when you look at your AHI...also look at the Central Index and back it out of the equation to have a picture of just the obstructive components (obstructive apneas and hyponeas) then evaluate if you think you want to try to reduce those components further.

[RandyJ]

Pugsy covered it I would only add: What is your EPR setting? If EPR is set to 2 or 3, you might get a slightly better AHI by decreasing or turning off EPR. You can experiment with the different EPR settings, it's only a comfort feature and not required for therapy.

For example, if you have EPR set to 3 it is decreasing your pressure on exhale by 3 cm. You might have fewer events if EPR were set to 2, 1, or off.

[Chuck Connors]

Yes, usually a minor adjustment upward in pressure BUT....that AHI...you need to evaluate all the components and not just the overall AHI.

The overall AHI on the S9 machines has the central index added in....Centrals we don't treat with pressure increases with this particular machine. If the AHI is predominately Central..a pressure increase is not indicated and might actually make them worse (rare but it could happen) but if zero to minimal Central index then yeah a little bump in pressure might help a bit.

So...when you look at your AHI...also look at the Central Index and back it out of the equation to have a picture of just the obstructive components (obstructive apneas and hyponeas) then evaluate if you think you want to try to reduce those components further.

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Thank you for the input, Pugsy. I will take a look at the numbers tonight. Is it fair to say that when someone on this site or elsewhere mentions what their AHI number is, that they are first substracting the Central Index before reporting the AHI number?

[Chuck Connors]

Pugsy covered it I would only add: What is your EPR setting? If EPR is set to 2 or 3, you might get a slightly better AHI by decreasing or turning off EPR. You can experiment with the different EPR settings, it's only a comfort feature and not required for therapy.

For example, if you have EPR set to 3 it is decreasing your pressure on exhale by 3 cm. You might have fewer events if EPR were set to 2, 1, or off.

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Thank you for your reply, RandyJ. I first needed to look up what EPR stands for. I've copied and pasted the information on EPR below for the benefit of others who aren't familiar with it. I'll take a look at my machine tonight to find out what my EPR setting is. I very much appreciate the information provided by you and Pugsy.

I'm grateful for having found this website. It was by accident that I did. I was looking at information on atrial fibrillation and this site was referenced. I've passed the word along to a relative and even a guy who was picking up equipment at a DME provider. Some good stuff in here. -Chuck-


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What is EPR (expiratory pressure relief)?

It is the most advanced compliance booster available for continuous positive airway pressure (CPAP) therapy. EPR provides your patients the highest level of comfort without compromising the effectiveness of therapy.

Why use EPR?

Some patients find it difficult to breathe against the continuous pressure of CPAP therapy. EPR solves this problem by dropping pressure during exhalation, making the patient feel that their exhalation is more natural and comfortable.

How does EPR work?

When the patient exhales, the Resmed S9 Elite CPAP flow generator detects the beginning of exhalation and reduces motor speed to drop pressure. The patient or clinician chooses one of three comfort levels to determine the degree by which pressure will drop:

Setting 1 – mild comfort (1 cm H2O)
Setting 2 – medium comfort (2 cm H2O)
Setting 3 – maximum comfort (3 cm H2O)

[LSAT]

I have been on CPAP for 3.5 years. I only check my data about every 3-4 months. In 3.5 years my AHI has never gone below 2.5. I don't care. I sleep well and feel well. To me that is the most important thing. You have only been on CPAP for a short time. You should be concerned about sleeping through the night, being comfortable with your mask and feeling good in the AM. You have plenty of time for tweeking your AHI.

[RandyJ]

LSAT - I agree with you completely but the OP specifically asked about leak and which other factors might be related to lowering AHI. And you may have seen it before, but if someone feels good with an AHI of 5, they wonder if they could feel even better with an AHI of <1.

[Pugsy]

Is it fair to say that when someone on this site or elsewhere mentions what their AHI number is, that they are first subtracting the Central Index before reporting the AHI number?

No...don't assume that the central index has been removed. I don't think anyone ever thinks to remove it and it really doesn't need to be removed unless you are wanting to evaluate the obstructive components only for purposes of possibly altering settings.

AHI is the hourly average for Apneas and Hyponeas...and the "apnea" part includes centrals and obstructives IF their machine scores centrals. Not all machine score them or they call them something else....like Respironics clear airway events. Pretty much same thing different wording..both are open airway cessation of breathing. Airway is open but no air flow. No obstruction causing the no air flow.

We used to not have centrals in the AHI because the machines didn't score them. We had no idea if we were having centrals or not. Knee jerk reaction for an elevated AHI...increase pressure. Most of the time it worked without issue. But now..since centrals aren't treated with pressure (by regular cpap machines) we can't rely on that knee jerk reaction to simply state "increase pressure".

There is a small percentage of people who might actually have centrals because of the pressure (long story I don't want to go into now) and increasing the pressure might make things worse..so would be possibly doing something that might make the AHI worse and not better. It isn't common but it isn't particularly rare either. I think I read somewhere between 10 and 15 percent of the people.

So since it takes just a brief question and discussion about that central index for evaluation needs it is always best to play it safe. IMHO
If your AHI was 4.9...technically okay but most of us would want to improve on that...so we say our AHI is higher than we want..but if that 4.9 included 3.9 central index...that leaves only 1.0 obstructive index and can't get much better than that...so increasing the pressure is unlikely to reduce that 1.0 very much and might (not a given) make the centrals worse.
Now if your AHI was 4.9 and 0.5 of that was central index..then your obstructive component is 4.4...well while technically "acceptable" being below 5...most of us will want to reduce it a little more..it is in our nature...and in that situation it probably is quite safe to nudge the pressure up just a little to see what happens.

Some centrals are normal occurrences. We all have them from time to time. We just don't do anything about them till they present themselves happening in large numbers consistently and we can't explain them all away as sleep onset or turning over in bed centrals (we often hold our breath when we turn over in bed and don't realize it). Not long ago I had a really bad night in regards to pain. I had 22 centrals in one night and my central index was 3.0 overall AHI was 3.9.
This is a rare thing for me. I suspect that I did a lot of tossing and turning (I sure remember doing it) and if I remember doing it I had a lot of fragmented sleep which means I had a lot of "sleep onset" time and I pretty much can explain the bulk of those centrals as "sleep onset" and they wouldn't be counted in a real sleep lab because I wasn't totally asleep. So for that night's data...I shrug my shoulders and move on.
It wasn't a normal night for me. With time you will see what your normals are and when you have nights that are unusual (and you will for sure have them from time to time) then you will learn that they just happen from time to time and are of no real concern and you chuckle, shrug your shoulders and move on.

[avi123]

I have been on CPAP for 3.5 years. I only check my data about every 3-4 months. In 3.5 years my AHI has never gone below 2.5. I don't care. I sleep well and feel well. To me that is the most important thing. You have only been on CPAP for a short time. You should be concerned about sleeping through the night, being comfortable with your mask and feeling good in the AM. You have plenty of time for tweeking your AHI.

Comment,

My AHIs were above 15 for 9 months after I started CPAPing, 14 months ago. But 3 months ago I switched my mask from F&P #431 and #432 FF to a nasal mask with a chinstrap and my AHIs dropped to below 3. I can't believe it even if I don't accept AHIs as a valid sleep disorder severity measure. See the report on my signature line.

[DoriC]

Avi, I know you don't consider AHI a valid indicator of good therapy but I'm curious to know how you're feeling since your AHI has dropped. I haven't been on the forum for awhile but in the few posts I've read, I notice that your posts are much more gentle and friendlier. Sounds like you're sleeping better, right? Anyway, all's well that ends well!

[Chuck Connors]

AHI- Apnea / Hypopnea Index 5.15
Hypopnea 0.53
Apnea 0.13
Obstructive 1.98
Clear Airway 2.51

Pressure Relief EPR x3
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Pugsy, just so I understand correctly, in the breakdown above, "Clear Airway" is a term used for Central, correct? If so, I would then take the AHI of 5.15 and substract the 2.51 Clear Airway number to get a 2.69 number, correct? Looks like I may want to lower the EPR, based on prior comments, to find out if that improves things. Thank you. -Chuck-

[Pugsy]

Pugsy, just so I understand correctly, in the breakdown above, "Clear Airway" is a term used for Central, correct? If so, I would then take the AHI of 5.15 and substract the 2.51 Clear Airway number to get a 2.69 number, correct? Looks like I may want to lower the EPR, based on prior comments, to find out if that improves things. Thank you. -Chuck-

You have it correct.. for purposes of evaluating things for some sort of pressure adjustment we look and the 2.69 number which is the obstructive components sin hyponea and obstructive apneas are from a collapse or partial collapse of the airway.

2.69 is not horrible but you see other with lower and want to join them. We have all done that.
Yes. If you wanted a minor change to see what happens turning down your EPR setting will alter the pressures a bit and increase the overall average a little bit. Will it do what you want? I theory it should but no guarantee though. Only way to know is to try it and it won't hurt anything to try it.

[Chuck Connors]

Last night - 5/1/12:
AHIApnea / Hypopnea Index 4.19
Hypopnea 0.86
Apnea 0.00
Obstructive 0.00
Clear Airway 3.33

Pr. ReliefPressure Relief EPR x1
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Monday night - 4/30/12:
AHI- Apnea / Hypopnea Index 5.15
Hypopnea 0.53
Apnea 0.13
Obstructive 1.98
Clear Airway 2.51

Pressure Relief EPR x3
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Thanks again, RandyJ and Pugsy for your suggestions and information. I decreased my EPR from 3 to 1 last night. Above are my numbers from Monday night and last night. -Chuck-

[RandyJ]

Chuck - wow, the apneas disappeared... I'd keep this setting for several days to see what the numbers are, and what happens with CAs. You really can't draw too many conclusions from one night's data... I would also make notes in how you feel when you wake up and during the day.

[Chuck Connors]

Tuesday night - 5/1/12
AHI - Apnea / Hypopnea Index 3.23
Hypopnea 0.39
Apnea 0.00
Obstructive 0.39
Clear Airway 2.46
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Wed. night - 5/2/12
AHI - Apnea / Hypopnea Index 2.93
Hypopnea 0.80
Apnea 0.00
Obstructive 0.53
Clear Airway 1.60
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It sure looks like changing my EPR from 3 to 1 was the correct call.

For some reason, SH didn't record the data from last night. Maybe the memory card wasn't seated properly since I traveled with the machine yesterday.

Thanks again!