First, have to say I love CPAP. It feels just soooo nice to be able to sleep.
Anyway, I've been on this for four months now, and it's made a huge difference. Once I got the mask issues worked out, I've been having really good numbers. AHI is rarely above 1.5 compared to 42 in the sleep study. Pressure a constant 13. Did a follow-up study a month back, and everything's great. Oxygen at 97%.
Here's the thing. Two weeks back I did a very simple nose surgery, turbinate reduction only (RFA) because before I could barely breath through my nose. Had been using nasal steroids to help. So, first couple of nights afterward, no CPAP just to make sure everything was good. Then started again, but decided to lower the pressure, just to be safe. Only took it down a notch to 12. No problem. No change in AHI numbers. So, did it again, down to 11. Now at 10.5. The AHI numbers are averaging under 1. No mask leaks or anything, so the figures should be right.
So, any reason why I shouldn't leave the numbers as is? Or go lower? Might play with the auto cpap just to see what the 90% numbers look like, but I'm pretty happy with plain continuous stable pressure. I guess the big question is is it possible that lower pressures could cause a decrease in oxygen saturation? And, is there any advantage to having a lower (or higher) pressure (besides comfort)? Has anyone else done this?
09-12-2016, 11:22 AM
(This post was last modified: 09-12-2016, 11:23 AM by OpalRose.)
You machine has an A-Trial feature. Go into Clinicial setting and choose A-Trial.
Set it to a 9-13 range and track it on SleepyHead.
You will have to choose the number of days for the trial....I believe 7 days is minimum.
It will find the 90% pressure that is best for you and after the trial will set it to Cpap mode at that pressure.
If it turns out you like the auto feature, then after the trial, set it to auto mode.
09-12-2016, 11:27 AM
(This post was last modified: 09-12-2016, 11:31 AM by richb.)
I am guessing that your diagnosis was primarily of Obstructive Apnea. Your surgery just might have reduced your need for higher pressures because you have lower negative pressure on inhalation. Keep an eye on your Sleepyhead charts and look for any increase in Hypopneas and or near Hypopnea events. You might see that before you see an increase in AHI as you experiment with slowly reducing pressure. Keep us posted.
P.S. I also had turbinate reduction surgery.
Like Rich, I had this surgery as well. I did not reduce my pressure after the surgery, but I did notice that my AHI reduced.
Thanks for the comments! So there should be no change in the oxygen levels with the lower pressure, right?
The lower pressure just made sense to me too since less blockage would seem to imply more efficient air-flow or something. Fits what you were saying, RichB. And yes, obstructive apnea only.
I guess I'll just go ahead and do the auto cpap and see what the numbers look like. I guess the reason I've been avoiding that, OpalRose, is because of the auto cpap they did for the sleep study. That drove me nuts because the pressure would jump up every time I went to sleep, thus waking me up. Constant pressure is so much more comfortable, IMHO.
Also, thanks RichB and Chill. Before I did the surgery I was reading about your experiences, just to see if it would be worth it. Now I'm thinking about a surgery (further down the line since I want to see how this turbinate reduction works out slightly longer term) for the nasal valve since that's possibly a bigger issue. I would say after the turbinate thing I'm maybe halfway there. I would love to be able to breathe perfectly freely! Anyway, though not perfect, it's still a huge improvement compared to before, so maybe I should be happy with that.
Thanks again for the input!
The air pressure does not directly affect your oxygen levels. The air pressure is not to deliver oxygen carrying air to your lungs. The air pressure is to keep your airway open so that air can reach your lungs naturally. Caveat: there are machines to treat central apnea that can more or less force you to breath, but we are discussion obstructive apnea here.
If you lower the pressure and your AHI increases, or the length of the events increases, but your AHI does not, then that can reduce the oxygen in your blood. It is complicated. There is a lot of interplay between different things.
As for CPAP and APAP, pick the one that lets you sleep the best. I have been using auto for about six months now and there are times when it wakes me up. I am going to try a period on CPAP to see if I sleep better. There is no one right answer for everyone. Keep thinking and keep watching your results over the long term.
Be very careful about having nasal valve replacement surgery. The ENT who did my turbinate reduction and septoplasty claimed I also needed this. A year later, according to another ENT, it had started to collapse again.
As an FYI, I don't feel the whole operation was successful so whether this was a contributory factor or not, I have no idea. But my point is if you feel you have significant improvement in your breathing, I would tread carefully about having more surgery.
Chill, thanks for the extra input. I knew that the machine didn't directly affect oxygen levels since it just helps keep the airway passage open while sleeping and doesn't actually breathe for you. However, it hadn't even crossed my mind about the length of apneas, which, as you said, would probably be affected by pressure setting. So, even though the AHI numbers could be staying the same, the apneas that do happen could last longer. That totally seems possible, and is exactly the kind of information I was looking for. I'll keep an eye out for that. Thanks!
And 49er, thanks for info on the nasal valve surgery. I'm going to a public hospital here and everything, including surgeries major and minor, is on a flat fee that's under US$20 a day. So, fortunately I can (probably) rule out greed as the motivation if the specialist recommends a surgery! Actually had a follow up visit this afternoon with the doc who did the turbinate reduction, and he basically said wait and see how the breathing improves over the next couple of months. I'll definitely "tread carefully" though. I guess if it's not absolutely necessary, it's probably better to not press my luck. Thanks again for sharing your experience.