After months of low AHIs, suddenly getting 8-12: why?

[BlueSky72]

I use a Resmed VPAP ASV, and was getting AHIs of 1.3-2.0 each night, then about 10 days ago I got 12, then 10, then 12 etc. Endless tweaking of my mask headgear has only got it down to 8.5.

I am getting depressed again and have no energy - I'm very sensitive to changes in the quality of my sleep as I am recovering from severe burnout after years of chronic physical and mental stress. I'm on a bunch of meds, including some sedating ones (antidepressants, pain meds) but none of them have been changed, so that doesn't explain it.

Please help, I am doing my best with my mask seal, washing my face well, putting the mask on as well as I can etc. Maybe I am tossing and turning more, and it's knocking my mask sideways a bit. I am getting desperate for a solution here.

[robysue]

Any chance you're coming down with something like the flu?

I've found that my AHI seems to be an early warning system of coming down with the flu or a very, very significant head cold.

Also: How old is the mask cushion? Any chance it needs to be replaced?

If the AHI continues to be this high for another week or so, I'd be letting the doc know about it if I were in your shoes.

[BlueSky72]

Any chance you're coming down with something like the flu?

I've found that my AHI seems to be an early warning system of coming down with the flu or a very, very significant head cold.

Also: How old is the mask cushion? Any chance it needs to be replaced?

If the AHI continues to be this high for another week or so, I'd be letting the doc know about it if I were in your shoes.

I have no symptoms of cold or flu and I don't feel like I'm coming down with anything.

The cushion/seal is about 2 months old.

I have let my sleep tech know but she says "it's not that high" which was disappointing, to say the least. The process where I live (NZ) is that you contact the sleep tech and if necessary they contact the sleep doctor - it's a public health system and that's just how they roll. However on Monday I will be calling sleep tech again and insisting she or the doc takes a closer look at things. Fortunately the doc is likely to take it more seriously than the tech. Keen to get another opinion through the forum though!

[Captain_Midnight]

If my AHI begins to creep up a bit, I first change out the unit filter (and it often needs it), then re-seat my cushion on the mask (sometimes it's not seated fully, and this can be difficult to notice), then snug up the mask a bit in all quadrants. You might also check the two hose connections.

Good luck.

[MagsterMile]

I was getting AHI's at 1.0 or below. Then, due to the then current Vpap Adapt (ASV) machine being replaced by a newer model, my AHI's are coming in at over 3.0 and a few 5.0's. Received my new machine just about a month ago. I called the therapist and suggested a 'pressure change' and was basically laughed at by her. Something has changed for you be it your mask, or hose or anxiety or who knows what it could be. Good luck and I hope you find out what is causing the change for you. Your changes are significant IMO and need to be addressed.

On more thing of note: the new Adapt had the ramp set at 20 minutes. I turned it off which has helped me a bit. There were no ramp capabilities on the older Adapt.

My therapist is critical of my checking my readings everyday on SH. I think she feels it makes me anxious.

[zorki1c]

I use nose pillows and my average AHI for the past six months is .5. But last week I started posting numbers between 1 and 2. Certainly not bad but a lot higher than normal. I usually use the same pillows a long time even though it's recommended to change them once a month. The pillows I was using seemed fine but as an experiment I switched to a new pillow. My numbers immediately dropped back to under 1.

[avi123]

A year ago I had AHIs going up above 25 and I did not feel differently than presently when my AHIs are below 5:



AHIs up to 20 do not indicate worsening of a sleep disorder, so said the sleep Doc Dr David Rapoport of NY Medical School.

THE APNEA-HYPOPNEA INDEX: USEFUL OR USELESS?
http://www.respiratoryreviews.com/sep02 ... Index.html

Show it to DOCs in NZ

[BlueSky72]

Thank you Captain Midnight, I changed the filter (it needed it) and today my AHI was 0.7, the lowest it has ever been! I still feel tired though, I guess it will take a few days to undo the damage that was done over about 10 days.

Thank you Magster, good suggestions and thank you for "getting" how I am feeling, that helps a lot. Isn't it silly how some therapists think daily AHI checking makes us anxious - what a load of rubbish. It's understandable that a person gets anxious if their AHI starts climbing, when they have been through hell to get diagnosed and treated effectively in the first place. When my AHIs are low, I am not anxious in the least. I am forever grateful to the forum for showing me how to monitor my own sleep quality, it is, after all, my body!

Zorki, thanks for your comments. I can see how checking your AHI enables you to get the most use out of pillows, because you can immediately see when they are ready to be changed.

Avi, I'm delighted for you that you can manage to feel fine with an AHI of 25, but clearly most people can't. I knew my sleep disorder itself wasn't worsening... my therapy was less effective than normal, so the solution would be to restore normal therapy. I am more sensitive to such changes because I am recovering from burnout - put simply, I don't have enough reserve in my system to get me through what would be a blip to someone stronger.

[sleepy1235]

Technically I find it very interesting that the change of filters fixed the AHI.

As an engineer I would think this would indicate some mechanical problem.

The mechanical pump should have some spare capacity to generate the necessary required air pressure as the resistance on the filter increases.

Incidentally I think that if you consider the path of the air from into the filter and out the bleed vent, most of the pressure drop occurs at those two locations.

Alternatively, when filters clog up they are notorious for releasing their contaminates. After the pressure delta reaches a certain level, particulates get released from the filter and enter the fluid flow, in this case into your lungs.

That reminds me. I have a stack of air filters and need to change mine.

[JohnBFisher]

Just as a note about checking your numbers on a daily basis... The next time you chat with the sleep tech, ask her off a diabetic should check their blood glucose levels daily. If she says yes, ask her why? The answer well bee that high (or low) blood glucose levels are dangerous or can cause serious damage to the body. Then ask how that differs from sleep apnea. Prolonged sleep deprivation WILL damage your body. It is used as a torture for a reason. And let's face it, driving while tired kills far too many people. You have every right to check how your therapy is progressing. Do not let the sleep tech tell you otherwise.

[sawinglogz]

The cushion/seal is about 2 months old.

I get at most a month out of mine before I get minor leaks that disrupt my sleep.

Glad the filter change helped, but I'd try a new cushion/seal as well.

[JohnBFisher]

I tend to agree about the mask. The extreme pressure changes of an ASV unit tends to cause the mask cushion to flex more than normal. After about one or two months this makes it stiff, which causes it to leak.

[old dude]

If my AHI begins to creep up a bit, I first change out the unit filter (and it often needs it), then re-seat my cushion on the mask (sometimes it's not seated fully, and this can be difficult to notice), then snug up the mask a bit in all quadrants. You might also check the two hose connections.

Good luck.

So are we saying here that a filter change/cleaning can cause AHI to creep up?

I just changed mine out and my AHI is up a little.

[Country4ever]

I would never have believed this if it didn't happen to me several times over the course of 6 years......but sometimes just changing the tubing and headgear can really bring your AHI down. I have no idea why that happens, but it's happened to me several times. Also......has your leak rate gone up too? If so, you might have a leak in your humidifier, which also happened to me a couple times. But make sure your tubing/filter/headgear, etc. is not much over 6 months old. I used to think they were just trying to make money by telling me I needed to change it every 6 months.......but I have learned that my numbers get worse right around 6-7 months of use.

[Captain_Midnight]

Sleepy1235 writes: Technically I find it very interesting that the change of filters fixed the AHI...As an engineer I would think this would indicate some mechanical problem...The mechanical pump should have some spare capacity to generate the necessary required air pressure as the resistance on the filter increases.

And makes an excellent point; something that I've wondered about myself.

My best guess is that with a higher pressure drop (from a cloggy filter) there is a bit of a time delay for the pressure transducer (or whatever pressure sensor the machine uses) to register a lower pressure (to you via your mask) and for the fan to spool up to a higher rpm in order to compensate back up to the required pressure. I also suspect that this might be a bigger factor in exhaust pressure relief modes of operation, and at the end of the exhalation cycle. (Guesses upon guesses.)

At any rate, it's happened to me enough times to validate the observation.

Oh, and it's not an original observation. I learned about dirty filters as one (of many) possibilities to explain a jump in AHI from a veteran poster hereabouts several years ago (Wulfman Den quite possibly, but I can't be certain.)

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