Quick question about pressure settings

Hello, I discovered this forum this morning and have been doing a lot of reading on it. To give you a background to my diagnosis, I was diagnosed in January 2007 following a home sleep test by a doctor at a private clinic. They prescribed me the Remstar Auto M Series C Flex, and I was not given a sleep study where they got me a titration reading, simply that the machine would work it all out for me (so I basically just had to put the mask on and away it would go).

I have been using it since then and in general it has worked very well. I do get the odd night where im a bit sluggish in the morning, but most days I feel normal. I was averaging 48 apneas an hour before it, so I can put up with the odd bit of tiredness compared to being dead of my feet beforehand.

Anyway, last night I woke up during the night and the air pressure coming out my mask was low (normally it is very strong). I felt terrible, and agitated and exhausted (like I used to before I had the treatment) so I assumed the machine had not worked properly when I had been asleep. I got another couple of hours sleep but felt the same in the morning and now feel shattered. However, as its just been the one night ever of this, im hoping it was just a one off, as on the surface the machine looks fine.

While doing some reading on here because of this, I found a way to access the clinicians menu on my machine (I actually had the manual which told me anyway but I had never looked at it!) and I found out a couple of things. Firstly, my weekly average AHI is 2.4 and my monthly is 3.0, which is fine. However, my weekly average pressure being used by the machine is 6.5 and my monthly 7.7. From reading on here, the optimum seems to 9-11.

So, I was wondering, are these figures a bit low? I was told I had really severe sleep apnea, so im surprised that only a bit above the base starting position would produce such a dramatic affect. I suppose that does include the times at the start when it starts at 4.0, and it seems to do the trick, but it seemed a bit odd to me.

I have never really looked into any of the science behind the condition until this morning, but im glad that I have now. But if anyone could advise me as to whether these pressure readings should be of concern, that would be great.

Thanks

Ally

There is no correlation between the severity of OSA and the pressure required to treat it (as far as I'm aware). Some have very severe apnea and only require a small amount of air pressure to treat it while others may have mild apnea and require very high air pressure to treat it. Your observation that a majority of people seem to be able to treat their condition with 9 to 11 cm is correct though.

The most important thing to focus on for optimum treatment is to get a mask that does not leak and that you can wear comfortably for the whole night. AHI numbers can be misleading if the mask leaks.

What does your leak data show and how does it compare with what it should be for your mask?

The literature that came w/your mask has a graph chart in it somewhere that shows the "allowed vent or leak rate" at various set pressures. You use that figure to compare to your reported leak rate to determine if you are experiencing too much mask or mouth leaking.

Thanks guys, off the top of my head I do not know my leak figures, but I will check the literature I got with my mask.

If I have a good nights sleep for the rest of the week, I will assume last night was a one off and not worry about it (assuming the literature suggests everything is fine). If not, I will go see my technician, the machine is under warranty still anyway if its broken.

Keep in mind;

Everyone has a bad night once in a while. Even those without OSA have bad nights from time to time.

Brenda

Cheers Brenda, I think it was the fact that its the worst night I have ever had and its far worse than anything I have had before (in 17 months too). My humidifier once blew the fuse on my machine, meaning I lost a couple of hours sleep in a middle of a night and I felt quite rough then. But this was ten times as bad as that, it was like being untreated all over again.

But yeah, its just been the one night so far, hopefully it will be a one off. I can see the clinicans menu now, so if it persists I can at least get some figures to go my technican with.

Have had similiar problems. After each new setting all goes well then the air pressure seems to drop to almost unnoticable. Along with that my fasting blood glucose starts to rise and I become more congested. My apneas are few, no more than 6 pr hr. Each time this happens we raise the pressure setting. started at 9 am now up to 14. Along the way we tried an automatic machine which worked great. I suspect we will ultimately settle on that machine as we cant keep pumping up the pressure. I do agree that when the pressure is negligible, the night sleep is pretty poor. Fortunately this doesnt happen often Hope you do well

Well I had a much better night last night, but still had the unexplained pressure drop.

I woke up at 2am and 5:30 am and felt like I had had proper sleep. I checked the pressure reading on my machine and it was at 15, so all looked well. Then when I woke up at 6:30am, the pressure felt low again and was back down to 4. At some point in that hour, even though I was asleep it put it back down to the minimum. It was not really an issue last night, as I had got plenty of sleep anyway and felt fine, but I will have to monitor it going forward.

Whether this is a malfunction of the unit or not, im not sure, I guess its too early to say....

Sounds like the machine is set for pressure 4-20. That means that the machine will stay at 4 as long as there are no events then raise the pressure slowly when an event is seen. The problem may be that the machine is not getting to the higher pressure needed to stop the event quickly enough. What was your titrated pressure? If it were me, I would start raising the lower pressure. I would start it at at least 8(you alredy know you go as high as 15). Then, if needed, I would raise it 1 point at a time till I found a starting pressure that seemed comfortable.
For most a pressure of 4 is way, way too low. I would feel like I was suffocating.
Some of us just don't do well on auto. I have to use my machine set as cpap to get a good nights sleep.

Brenda

I did not have a titatron, or a full sleep study, I had a home sleep study kit which showed up severe sleep apnea. They gave me a 2 week trial with my machine, which made a massive difference and I bought it. They told me how to put the mask on and said the machine will sort it all out for me, which frankly it has.

I do not really want to change any of the settings without having consulted my technician or consultant first, especially since this has only started happening in the last week or so. Prior to this it was absolultely fine.

Thanks for the advice though, I will see how it goes and if necessary speak to my technican. If what she suggests does not work, then I will try alterting the settings.