Pressure Averages

I still am confused by the numbers I see on my machine every morning. My APAP was set to 7-13 for the longest time. I have lost a considerable amount of weight and had been having problems with my therapy after that. I started waking up every 2-3 hrs. again, going to the bathroom etc. My 90% pressure numbers consistently said 8.0 % for both 7 day avg. and 30 day avg. It finally dawned on me that maybe this pressure was too high. I set the pressure to 6-11 and immediately my avgs. started dropping. I now have it set at 5-11 and after about 2 or 3 weeks my 7 day avg. is 6.0 and 30 day avg. has dropped to 6.8. I guess after a month or more it might drop more. So far am not really sleeping much better, maybe a tad. I can't believe the Dr. didn't see the need to drop my pressure but in all fairness I haven't seen her since last Jan. and at that time I only had about 2 weeks of data on the machine. I still don't see why the number stayed at 8.0 for so long when obviously I was needing a much lower pressure, even less than the 7 it was set for. Now I'm wondering if I should set the bottom number to 4 and see how that goes. My apnea is much improved as these figures bear out since I have lost 60 lbs. My original setting was 9 so if I am down to 6 or even below that is a great improvement. Just wish I could see a better improvement in my sleep. I had great therapy the first year when I was heavier and now that I am thinner my therapy not so good. Anyone have an explanation why that number stayed at 8 for almost 2 years without moving? Doesn't make sense to me. If I'm really a 6 or less now you would think it would have read 7 since thats where the lower number was set. Any ideas are greatly appreciated.

Hi,

Do you have AHI numbers? Or print-outs from the data card that you can post? I'd love to see what is going on. Without that, it is hard to even speculate.

I do see two myths that you seem to be operating under. First, that severity of OSA is correlated with weight. Second, that severity of OSA is correlated with pressure.

While I have nothing to base anything on, my impression is that your OSA has gotten a little worse over time, which may be why you are not sleeping as well. I suspect that it might be compounded by you lowering your pressure. My theory is that your upper pressure needed to be a little higher to knock off the events that it was seeing. Now that you have set the pressures lower, the machine takes longer to ramp up when those events happen, and it is missing them as a result. Setting the upper pressure lower then caps the machine's ability to do anything. Many folks find that it is hard to breathe on pressures less than 8 since they don't seem to get enough air. That could also be impacting you.

The best course of action would be to go back in for a follow-up sleep study. Barring that, the next best thing would be to have the data read from your data card (or at least post it here), and consider asking your sleep doctor to try an overnight oximeter test.

-john-

I don't think I explained myself well. My pressure needs have dropped, why would I raise the upper limit? My question was why the numbers on the readout never budged from 8.0 for 7 & 30 day 90% pressure all this time( over a year) Now that I have lowered the bottom number to 5.0 and the upper number to 11.5 my averages are dropping so obviously I am needing less pressure not more. I'm a little confused why you would think I need to raise my upper range as I never reached this number even when titrated at 9. I don't have the software but when the Dr. read the card last year she said she would now based on just a small amount of data off my card titrate me to 8. I have since lost even more weight and probably have less fat to prop open in my throat. Anyway can anyone surmise an answer to this puzzle? Just curious why that number never budged until I lowered the ranges. My AHI this morning was 0.2 and it has always been below 1.0 so my therapy is obviously stopping the apneas. Why I am still waking up is a whole different question and I will probably have to have another sleep study to see if anything is going on that can be pinpointed. My leaks are great too, I never had any problems other than I don't find the mask the most comfortable thing and since I have gone to FF its worse.

Several other things contribute to poor sleep, no just sleep apnea. Congrats on the wt loss! I too was able to reduce my pressure following wt loss; mine wt loss is ongoing and I have allergy-sinus-congestion issues so my pressure needs vary making APAP much more comfortable for me.