Excessive Hypopneas

[kenmac1005]

I have been struggling with this issue for about six weeks now since finally getting ResScan to work with data from my S8 VPAP 25. i now run the report on Detailed data every morning.

My AHI is consistently around 10 and its almost all hypopneas. I have only 3 to4 apneas a night.

One suggestion which was backed up by my doctor was to increase pressure on the VPAP to reduce the hyponeas. He said he believed the hypopneas were probably evidence of Supine hypopnea from sleeping on my back. I'm pretty confident that I don't sleep much on my back given anecdotal evidence from my wife.

But I took the advice and increased pressure across the board. It was EPAP 4, IPAP 14 and PS of 2. I increased the pressures to 6/16/4.

The result was a large increase in Apneas no decrease in Hypopnes and AHI of 23.

I persevered for 3 nights with similar results and last night went back to 4/14/2.

After frightening the crap out of myself for three days. Last night as i said was AHI 9.7.

Can anyone offer arational for what happened and suggestion for moving forward.

[Pugsy]

Historically the S8 machines seemed to record higher hyponea count. Some people used to shrug it off and do some mental math and cut the Hyponea number in half. I don't know that I would agree to going that way because not everyone had a higher than usual Hyponea index.
Instead I tend to wonder if maybe those Hyponeas were centrals being flagged in the Hyponea category.
In the S8 machines there is not a separate classification for centrals like there is now with the S9 machine.
I don't know what ResMed did with the centrals it sensed with the S8 machines. We know that they were sensed because the machine in APAP mode won't respond to events that appear to be central in nature and not have the normal obstructive event precursors with it (snores and flow limitations).
Pre PR S1 Respironics machines would lump any centrals into either the obstructive or hyponea category. I found that out last summer from someone in Respironics who was familiar with the M series and older machines and how they scored stuff. I don't know what ResMed did with theirs though.

Since an increase in pressure seemed to make things worse...makes a person wonder if those hyponeas were central in nature and more pressure made them worse.

Is your VPAP a straight bilevel or do you have the Auto? If you had the Auto and you saw the hyponeas and the machine sat there and did nothing to try to prevent them then we would assume that they didn't have any obstructive precursors and might be central in nature. Impossible to know for sure though. Just speculation on my part.

[kenmac1005]

Pugsy

Thank you. I really appreciate your help. It is an S8 VPAP Auto 25. I have it programmed to VPAP mode should I have it programmed to Auto

Also for future reference I'm due for a new machine in a few months. Which of the S9 machines collects the most appropriate data for sorting out the Centrals from OSA.

Ken

[Xney]

I had a bunch of residual hypopneas, although not to the same AHI number as you. An ASV removed all of them, but I had to pay for it myself due to not being something insurance would do.

Usually increasing IPAP will remove hypopneas, but yours is already pretty high. It may be one of those things where you might have to play around a bit to see what works to get rid of them (if anything will). How do you feel in terms of sleep? Is it good or bad? remaining sleep apnea symptoms?

You have a pretty big spread between EPAP and IPAP, so does it feel like there's a big pressure change? You might want to reduce the spread a bit and see how it feels or goes. Or is the machine configured such that it's a minimum EPAP and maximum IPAP, and the pressure support is the actual difference?

[kenmac1005]

So the ASV removing the excessive hypopneas would indicate for you that they were Centrals right?

Yes the S8 VPAP Auto 25 is programmed Min EPAP (4) and Max IPAP (14). The Av IPAP is around 8 to 10 well within the range. When I increased the ranges to 6 and 16 the av pressure went 10 to 12.

I think I will be more aggressive with my doctor and see if another sleep study is warranted. If they are centrals am i right in assuming that during sleep my breathing goes into a very shallow mode for relatively long periods of time which is then recording as hypopneas.

Ken

[Pugsy]

The S9 equivalent of your current machine would be the S9 VPAP Auto. It does record a separate category for centrals.
In fact all the S9 models that are full data machines...will flag centrals now.

For sure you probably should be talking to your doctor about all this.
How come you ended up on VPAP to start with?
You've tried higher pressures and have more hyponeas...have you tried lower?

[RandyJ]

Maybe you could borrow a loaner that records centrals for a week to check on things?

What Pugsy says about the S8s aggressively recording hypopneas is true. I use an S8 Elite every few months when I travel, and it records quite a few hypopneas, which I ignore. When I'm using that machine, I just check the AI (apneas). However, most of the time I'm using a machine that records centrals, and I rarely have any. So I know the high hypopneas is just the S8 being an S8...

[kenmac1005]

How I ended up with the S8 VPAP Auto 25 was that originally my DME gave me a secondhand S8 CPAP which was over three years old.. It had not even been reset to zero so showed years of service. By the way charging my insurance $2250 for it.

I kicked up a such big stink with the DME that they then gave me the most expensive machine they had on the shelf at the time. At least that is what the techo told me when he personally delivered it.

Its really never been properly set by them and most of the settings are default. With the help of your excellent forum I'm beginning to understand not just the vagaries of my condition but the complexity of the therapy. Thanks for all your help.

I think what i need is another conversation with my doctor to eliminate the suspicion that the S8 is not giving an accurate picture. Or if the hypopneas are centrals then get equipment to effectively record and manage them.

I guess the bottom line is that I feel the therapy is only partially working. I feel more refreshed after sleep than without the CPAP but not fully so and often still drowsy during the day.

Regards Ken

[Todzo]

I have been struggling with this issue for about six weeks now since finally getting ResScan to work with data from my S8 VPAP 25. i now run the report on Detailed data every morning.

My AHI is consistently around 10 and its almost all hypopneas. I have only 3 to4 apneas a night.

One suggestion which was backed up by my doctor was to increase pressure on the VPAP to reduce the hyponeas. He said he believed the hypopneas were probably evidence of Supine hypopnea from sleeping on my back. I'm pretty confident that I don't sleep much on my back given anecdotal evidence from my wife.

But I took the advice and increased pressure across the board. It was EPAP 4, IPAP 14 and PS of 2. I increased the pressures to 6/16/4.

The result was a large increase in Apneas no decrease in Hypopnes and AHI of 23.

I persevered for 3 nights with similar results and last night went back to 4/14/2.

After frightening the crap out of myself for three days. Last night as i said was AHI 9.7.

Can anyone offer arational for what happened and suggestion for moving forward.

Many of us who read medical research papers about issues affecting Obstructive Sleep Apnea have run across the concepts of breathing stability and CO2 reserve (e.g. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2809244/ ).

So I think when you increased your pressure your breathing reflexes, if you will, were not ready for the change so the increased breathing washed out more of your CO2 and so reduced circulation and metabolism. This starves cells and increases inflammation. FWIW - I do pulse oximeter guided breathing to keep my CO2 levels more near optimum. The first sign that I am breathing to much is that my nose stuffs up. I am not kidding at all!! Anyway, the inflammation likely caused the apneas.

If I were you I think I would:

Try less pressure. More did not work so the direction may have been wrong. You are watching your data regularly so problems are likely to show up quickly.

Raise the head of your bed a couple of inches. It is cheap and easy to do and is likely to reduce your need for pressure. The less pressure you use the more your breathing is likely to be stable.

Consider breathing re-training. Using this I have reduced my need for pressure from 15 to 8 in about a year.

Have a great week!

Todzo

[RandyJ]

I think what i need is another conversation with my doctor to eliminate the suspicion that the S8 is not giving an accurate picture. Or if the hypopneas are centrals then get equipment to effectively record and manage them.

I guess the bottom line is that I feel the therapy is only partially working. I feel more refreshed after sleep than without the CPAP but not fully so and often still drowsy during the day.

Regards Ken

Your doctor could write an order to "borrow" a machine that records centrals for a week or two. It would be a lot cheaper than another sleep study. Then at least you will know if you can ignore the hypopnea index portion of your AHI.

As for not feeling 100%, it can take a while after beginning therapy. For some, several months. I myself noticed a decrease in feeling drowsy within an hour of waking right away, but never really experienced what they call "the miracle." In my case, I also had low Vitamin D, inflammation and other issues that would prevent me from feeling it.

Good luck!

[The Sheikh]

Hi Ken,

I, too, have problems with hypopneas, at least according to the index.

I'm using an ASV machine for severe centrals, minor OSA and moderate CSR - and they are almost completely gone. But I get about 15- 25 hypopnea events each night. When examined on a breath by breath basis, they are NOT significant cuz I keep breathing through them, but at a reduced ventilation rate. That's OK with me, cuz the O2 sat stays up over 94% all night.

So, bottom line is when you get the flow data breathing chart, look to see if the hypopneas are just a reduction in breathing amplitude, but you continue to ventilate thru them. Might be non-events you can live with.

You may also have some centrals activity since a higher pressure caused a worse AHI. I have the same symptoms and found by setting my ASV at the minimum pressures, I found the overall sweet spot for best AHI and rest. You may find later on that an ASV machine is best for you.

Post your results when you get them.

Tom

[Pugsy]

So, bottom line is when you get the flow data breathing chart, look to see if the hypopneas are just a reduction in breathing amplitude, but you continue to ventilate thru them. Might be non-events you can live with.

Post your results when you get them.

The S8 model based machine that he is using doesn't give flow data. He would need a S9 to get the flow data.
ResMed didn't start giving flow data graphs until the S9 models.

[The Sheikh]

The S8 model based machine that he is using doesn't give flow data. He would need a S9 to get the flow data.
ResMed didn't start giving flow data graphs until the S9 models.

Thanks, Pugsy. Yes, when Ken said, "Also for future reference I'm due for a new machine in a few months. Which of the S9 machines collects the most appropriate data for sorting out the Centrals from OSA." ... I was referring to a time when he does get his flow data available.

I have an older PR Advanced SV machine that does not show the flow data either, so can appreciate the limitation. Fortunately, my S9 Adapt ASV has the flow data available. If I looked at the limited PR machine data only, I would probably panic when seeing all those hypopnea events, but they are not really significant when viewed breath by breath on the Adapt.

As we know, the coarse "event charts" are really of limited value when trying to see what's really going on. Technology marches on.

T