Adjusting CPAP pressure

hey guys,

Just to give a bit of background.... I was diagnosed with sleep apnea about 14 months ago with an AHI of 17.7. The recommended pressure from the lab technician was 14 although it was for a full face mask. After a couple of weeks with a brick and a full face mask, I got a Resmed S9 Autoset with a Swift FX mask and switched to a Dreamwear mask in the past few months.

When I got the Resmed S9, since it was supposed to adjust the pressure to my needs, I left the max pressure at 20. Then back in March I was looking at the statistics and saw that the pressure was rarely going over 10. So I decided to lower it to 10. Then about 3 weeks ago, I noticed that the pressure was rarely going over 8, so I decided to lower it to 8. And then last night, I tried 7.... In all cases, my AHI is under 1... Here is the screenshot:



How much can I rely on this data? Can I keep lowering the pressure until I see my AHI go above 1 average? I would hate to rely on bad data and not get the treatment I need.

thanks!

Franck-

Looks like I didn't do a proper embed:

There is no reason to lower max unless the machine is running away to high pressures for no good reason. It helps to have headroom available for the rare night (cold, allergies, alcohol, late meal, etc) when a higher pressure might come in handy for a few moments during that one night. I leave my max all the way up and will do so until that causes a problem. It is generally the minimum pressure that is key when a patient is tweaking his own APAP settings.

The larger principles of dial-winging an APAP, in the case of some of us, are that once you have home-machine-reported AHI as low as possible, you tweak minimum pressure(s) based on comfort and how well you feel the next morning and throughout the day, as averaged over time. And for some, once AHI is low, they still find that they feel better in the mornings when they keep pressures a cm or two more than that. Although raising pressure may not make a difference with reported home-machine numbers, it may further stabilize the airway making for a more restful sleep. Also, some find that they are just plain more comfortable falling asleep with a pressure that is higher than what is needed for simple prevention of apneas and hypopneas. That fact is often little-understood by professionals who do not personally use PAP at night. Of course, if someone happens to be especially sensitive to slightly higher pressures in a way that triggers some centrals, that will show up in an increase of AHI, indicating the advantage of lowering minimum back down. So there is no danger in searching for a personal sweet spot with the minimum, in search of feeling as rested as possible and as comfortable as possible, as long as AHI stays low.

Looks like you are one of those lucky people who simply don't need much pressure to hold the airway open.
Your minimum is 4 cm and that's as low as the machine can go.

If you like EPR at 3...if you lower the maximum from 7 down to something lower you will lose some EPR because the machine can't go lower than 4. Right now with these settings you are getting 7 cm for inhale and 4 on exhale...if you lower the max to 6...you would get 6 inhale and 4 exhale..you might not be comfortable at that setting because there's not going to be a lot of air movement.

So you might still be able to get good therapy at the lower pressures but it might not be all that comfortable. You are getting down to the range where people complain of feeling like they are suffocating (they aren't but it can sure feel that way).

If it were me and I was sleeping good and feeling good...I think I would leave it where it is. It hurts nothing to use maybe a tiny bit more pressure than is technically needed.

I am feeling a bit drowsy this morning so maybe indeed pressure 7 is not as good as 8. At the same time, my 3 year old has woken me up multiple times during the night in the past few days so I might just be overtired because of that:)

One of things I am trying to figure out is a way to measure is whether my sleep apnea is improving in general. Since I regained my stamina (thanks to my CPAP machine), I have been running a lot, losing weight, lowering body fat, etc... Since I was diagnosed, I have lost about 15lbs but more importantly I have lost about 3% body fat. My neck size has also reduced from 17" to 16.25". I still have some ways to go but I was hoping that the data from my CPAP machine could tell me if things were improving in general. I thought that if I was able to lower the max pressure over time and still having an AHI under 1, it might indicate that I am improving. But from your comments, it seems that it might not necessarily mean anything like that.

Is there any way at all to tell whether I am improving from the stats on the CPAP machine or by tweaking things differently?

FranckDG wrote:Is there any way at all to tell whether I am improving from the stats on the CPAP machine or by tweaking things differently?

Not really...at least in what I sense you are wanting to see.
About the only thing is that with the pressure reductions still showing acceptable therapy it could mean that with the weight loss and general overall physical level improvement you may not need as much pressure to hold the airway open.
That said...it wouldn't be impossible for a person who loses excess weight (and that excess weight was the sole cause of the OSA) to get down to a point that if they had a repeat sleep study that the AHI would be below diagnostic levels and they might not meet diagnosis criteria and might not need the machine.
A lot depends on how much weight is involved and was the weight the sole cause of the OSA to start with.
Losing weight wouldn't help me...my OSA developed post menopause (very common for women) and I was a skinny Minnie when I first developed OSA symptoms a few years ago. I really didn't have any excess weight at the time...just everything starting to sag and get floppy with menopause...boobs, butt, belly and the airway tissues in my throat. I do have more pounds on me now than I did back when I was diagnosed but I know that even if I got in better shape and lost some pounds...I would still have the saggy, floppy airway tissues.

There's really no way to know if your OSA is no longer present because of getting in better shape without having a repeat sleep study without cpap. Even if you used the minimum of 4 cm pressure all night long and no events showed up...that 4 cm does have some therapy value and there's no way to know if the 4 cm was preventing the airway collapse or you just didn't have any collapses without a follow up sleep study.

Now what you could try....if you could be comfortable with 4 cm...is try 4 cm all night (fixed with no EPR) and you might get a sort of answer...if you saw a dramatic increase in the AHI then you would know that you still have OSA that needs treatment but you just got lucky and with the weight loss the pressure needs went down.
If your AHI was still below 1...no way to know with absolute certainty that nothing happened without a follow up sleep study.

Some people are okay with 4 cm...some people feel like they are suffocating and simply can't sleep at such low pressure.

So if you are wondering if all this getting into better shape means that you improved your situation and you no longer need cpap...it might or it might not. We know that it lessened the pressure needs but we don't know if it eliminated the need or not. Sometimes the OSA causes the weight gain...sometimes the weight gain causes the OSA. A chicken or the egg situation for sure.

Bear in mind that if it was indeed soley the weight that was the cause and with the loss of weight the OSA becomes below 5.0 AHI with no cpap...people often put the weight back on and get right back in the same situation.

FranckDG wrote:. . . whether my sleep apnea is improving in general. . . .

The more important question is the other one you mention--whether or not your overall health is improving because of the efforts you are now able to make because of successful PAP therapy.

Successful PAP therapy used during all times of sleep banishes sleep apnea into nonexistence during the therapy. There is no improvement possible for something that does not exist.

As to whether something could happen that would mean PAP is no longer useful to you at all, that fact could only be established definitively by an overnight PSG sleep study at a lab/center performed after several days of your being off of PAP therapy. I am unaware of that happening for the average OSA patient; it generally only happens when there is an obvious anatomical abnormality addressed surgically (such as a tumor of the airway) or when sudden weight gain is followed by immediate OSA diagnosis and then rapid weight loss before the brain rewires itself into OSA permanently.

@Pugsy: thanks for the tip! I will try a pressure of 4 for one night and see what I get. In terms of weight, I am 6'3 and was 230lbs when diagnosed. I am now 215lbs. 10 years ago when I was OSA free, I was 195lbs but I don't think I can get back to that. And I don't think weight is the whole story for me either. I am planning to try this also because that may also help: http://sleepapneadidgeridoo.com/didgeri ... nt-of-osa/. Have you tried? This might work better for you as well. Helps with the floppiness in the right parts supposedly.

@jnk: I think I will most likely always need PAP therapy but I am just trying everything I can to get better in general. A chinese medicine expert friend of mine recently told me something interesting... If you use the PAP therapy to breathe at night, then your body will adjust to it, your floppy tissues will stay floppy and might even get floppier since they don't need to work as much. Not sure if this is true but it does have a ring of truth to it. I am going to try the Didgeridoo for example to see if maybe I can address some of that floppiness.

No, I have never tried the digeridoo for any number of reasons but the main one is I know that I am lazy and I wouldn't put forth the effort needed..lots of work and you can't ever let up and there's no real evidence that it would work in my situation. It's a maybe fix...and my oxygen levels went too low for me to risk a maybe fix. Maybe if my OSA was really mild...but mine isn't.

As to the use of cpap potentially making a person's airway tissues "more floppy"...I don't buy into that at all.
All the cpap pressure does is hold the airway open a bit while we sleep...we still use regular air the other 18 plus hours we don't sleep. Now maybe (big maybe) someone on a ventilator 24/7 for a prolonged period of time...maybe but I just don't see it at all for someone who only uses it for 6 to 8 hours a night.

There's also something else besides the floppy airway tissues...there's the size of the airway and not much we can do about that part short of some major surgery which holds no appeal to me at all and there's no guarantee that will work either.

Pugsy wrote:. . . As to the use of cpap potentially making a person's airway tissues "more floppy"...I don't buy into that at all. . . . All the cpap pressure does is hold the airway open a bit while we sleep . . .

+1

FranckDG wrote: @jnk: . . . A chinese medicine expert friend of mine recently told me something interesting... If you use the PAP therapy to breathe at night, then your body will adjust to it, your floppy tissues will stay floppy and might even get floppier since they don't need to work as much. Not sure if this is true . . .

I am sure it is not.

My wife is part Chinese, and I have nothing against multicultural medical approaches, especially from cultures as ancient as the Chinese. But PAP therapy didn't exist before, oh, say, 1984 or so. Therefore, I do not consider Chinese traditional medicine to have any relevant useful info on the effect of PAP on the human airway.

The more you learn about the nature of OSA, the more it becomes clear that, other than in certain exceptional circumstances, the mechanical aspects of it are MUCH more complicated than 'floppiness,' and the body, brain, and nervous system adapt to the condition in a way that is much more complicated than would allow a person's simply becoming overall "healthier" to magically fix the OSA. Bad health may have played a role in what led in to the condition, yes--but that, sadly and unfortunately, does NOT mean that simply improving overall health will reverse the condition.

At least when it comes to moderate-to-severe OSA, as the body's systems adapt to the long ongoing battle between sensitivity in the airway and blood gas problems during sleep, some 'rewiring' occurs as the body scrambles to compromise between bad sleep and bad breathing, usually leading to a greatly DEsensitized, nonresponsive airway during sleep. Once that rewiring happens, then unless you have a magic way to rewire and rework your hormone/nervous system's wiring and plumbing, you will continue to remain in need of PAP therapy for optimal sleep.

Although the solution to OSA (PAP therapy) is a relatively simple mechanical sort of thing, the condition itself rarely ever is. That is why it has repeatedly been found that if you do something to prevent one part of the airway from collapsing, another part of the airway just ends up collapsing instead, once OSA has set up residence in your body. PAP manages to solve that problem along the entire length of the airway in a way that other approaches cannot (so far) accomplish.

Then again, of course, I might just be willing to ignore all those facts if I had a Chinese herb to sell you.

Can things like the didgeridoo improve things somewhat? Sure. Can overall health improve some aspects of what PAP is fixing? Yep. Can either of those approaches dependably put a significant number of people across the other side of the line of OSA diagnosis? I don't think anyone directly involved with OSA thinks so--even the ones who may claim otherwise because of having a product to sell; they just pretend to believe it.

In my opinion. And boy do I have a truckload of 'em.

playing the didgeridoo suppose to help!

FranckDG wrote:@Pugsy: thanks for the tip! I will try a pressure of 4 for one night and see what I get. In terms of weight, I am 6'3 and was 230lbs when diagnosed. I am now 215lbs. 10 years ago when I was OSA free, I was 195lbs but I don't think I can get back to that. And I don't think weight is the whole story for me either. I am planning to try this also because that may also help: http://sleepapneadidgeridoo.com/didgeri ... nt-of-osa/. Have you tried? This might work better for you as well. Helps with the floppiness in the right parts supposedly.

@jnk: I think I will most likely always need PAP therapy but I am just trying everything I can to get better in general. A chinese medicine expert friend of mine recently told me something interesting... If you use the PAP therapy to breathe at night, then your body will adjust to it, your floppy tissues will stay floppy and might even get floppier since they don't need to work as much. Not sure if this is true but it does have a ring of truth to it. I am going to try the Didgeridoo for example to see if maybe I can address some of that floppiness.

You might want to read back through the discussions on the forum about that before you do.

viewtopic/t112181/search.php?keywords=didgeridoo

Sleep apnea can be caused by any number of factors.
Each person needs to be able to identify what their specific one(s) is/are.


Den

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I see no reason or advantage to lowering the maximum pressure if you are sleeping well with it wide open. It's like insurance - there if you need it and not used if you don't. Pressure needs can change for all kinds of reasons including sleep position, colds, alcohol use, etc. It's the job of your wonderful cpap machine to figure out the pressure you need and give it to you.

Now, increasing the minimum pressure is another matter and can make the therapy work much better in some cases. What works best for me is 13 - 20 because as soon as I fall asleep it quickly rises to at least 13. But my untreated AHI is 80 so I'm way into the severe apnea territory.