Question re pressure results

I am still battling my Swift mask but making headway. Last night was one of the best. AHI.9, Leak@95th was 3.6. However my pressure was from 7.6 to 12.7 with a 95th of 11.3. My settings are 6 to 14. Some nights my pressure is around 6 to 8 or 6 to 9. Why does this vary? Is that normal? Pleae help me understand more about Apnea and CPAP. I am assuming that the machine will exceed your pressure settings when it senses an apnea? Some nights I see very high numbers in the flags on Rescan. Some nights there are lots of flags. Last night there were only 3 and the pressures shown on the flags are 10,13 and 16. My oxygen levels never fell below 92!! I try and avoid sleeping on my back and last night I obeyed my command!! Other nights I give in!! Leak rate would have been even better but the rainout caused a few bad leaks and I moved once and the mask lost it's seal. I can see a light at the end of the tunnel.

Bob

cortez356 wrote:I am still battling my Swift mask but making headway. Last night was one of the best. AHI.9, Leak@95th was 3.6. However my pressure was from 7.6 to 12.7 with a 95th of 11.3. My settings are 6 to 14. Some nights my pressure is around 6 to 8 or 6 to 9. Why does this vary? Is that normal?

The pressure range on an AutoSet is designed to vary at least some from night to night based on your pressure needs for the night. Somethings that can affect the high end of the pressure needed for a particular night might include whether you've got a head cold or nasal congestion and sleep position. But for many people, there is (eventually) some long term trends on where the max and 95% pressure levels tend to settle. You say your pressure settings are 6--14 cm. That's a pretty wide range. How was it determined? Did you have a titration study done in a sleep lab? If so, do you know what your titrated pressure was? Most folks tend to want the max. pressure setting a bit above their titrated pressure and a bit lower for the min. pressure setting when running in Auto mode.

Pleae help me understand more about Apnea and CPAP. I am assuming that the machine will exceed your pressure settings when it senses an apnea?

No. The machine will NOT exceed your max pressure setting under any circumstances. That's why it's called the maximum pressure setting.

Some nights I see very high numbers in the flags on Rescan. Some nights there are lots of flags. Last night there were only 3 and the pressures shown on the flags are 10,13 and 16.

The flags in ResScan correspond to individual apneas that occured that night. Lots of flags means you had lots of apneas. Very few flags mean very few apneas. The NUMBERS on the flags are the length of time in seconds the corresponding apnea lasted. So those three apneas from last night lasted 10 seconds, 13 seconds, and 16 seconds respectively.

My oxygen levels never fell below 92!! I try and avoid sleeping on my back and last night I obeyed my command!! Other nights I give in!! Leak rate would have been even better but the rainout caused a few bad leaks and I moved once and the mask lost it's seal. I can see a light at the end of the tunnel.

Bob

If you get lots more flags on your back or if the numbers on the flags are much larger when your sleeping on your back, then you might very well have a positional component to your apnea, and trying to avoid back sleeping may make sense. As for leak rates and rainout: That 95% leak rate of 3.6 L/min means that for most of the night you were leaking at a rate LESS THAN or EQUAL TO 3.6 L/min. That's not a bad 95% leak rate, but the real trick with leaks is whether the mask leaks woke you up and/or kept you up long enough to not get a good night's sleep.

Good luck!

robysue: Thank you for the explanation > I was never titrated as the AHI on my sleep lab test did not meet their standard for needing a mchine. The Dr. was very wrong as my results have proven. Before I got my machine I bought a Pulse Ox 7500. The results were scary. Often blow 85 and even lower. Sleeping on my side improved the results but still horrible. I asked the Dr. for a prescription and those pressure #'s are what he wrote. Witht he S9 my oxygen levels are superb!! Due to mask problems I dont have any long term results but I think I could lower the high limit pressure a point or 2. Early on I did see some that were 13 but that was rare. Most seem to be 11 or 12 max. I could try 13 for a week and see what happens?

Thanks

Bob

cortez356 wrote:I am still battling my Swift mask but making headway. Last night was one of the best. AHI.9, Leak@95th was 3.6. However my pressure was from 7.6 to 12.7 with a 95th of 11.3. My settings are 6 to 14. Some nights my pressure is around 6 to 8 or 6 to 9. Why does this vary? Is that normal? Pleae help me understand more about Apnea and CPAP. I am assuming that the machine will exceed your pressure settings when it senses an apnea? Some nights I see very high numbers in the flags on Rescan. Some nights there are lots of flags. Last night there were only 3 and the pressures shown on the flags are 10,13 and 16. My oxygen levels never fell below 92!! I try and avoid sleeping on my back and last night I obeyed my command!! Other nights I give in!! Leak rate would have been even better but the rainout caused a few bad leaks and I moved once and the mask lost it's seal. I can see a light at the end of the tunnel.

Bob

Here is an old post of mine:

roster wrote:Do you know if you have positional sleep apnea? It may be much on your back than on your stomach or sides. Here is an extract from a post:

rooster wrote:............
I would like to make you aware of "positional sleep apnea" (PSA). Maybe 40% or more of patients have PSA.

PSA means the apnea is much worse in one sleeping position (on the back) compared to other sleeping positions. For example, my sleep apnea is very severe when I am sleeping on my back.

For people with PSA, the sleeping position can have a big effect on CPAP pressure requirements. For example, I have been titrated in a sleep lab and at home have confirmed my pressure requirements for different positions. On my back I require a pressure of 19 cm (Yow!). On my side or stomach, a pressure of 8.5 cm is sufficient. So I have some devices and train myself to sleep only on side or stomach and use pressure of 8.5 cm.

You may want to make some observations about the possibility of PSA in your case. There may be information from your lab PSG also.

.............

It's normal for pressure to vary a bit when you're running in apap mode. And leaks can cause pressure increases the the machine tries to compensate for the leak. Also, we just sleep differently on some nights; but that doesn't need to be a big deal.
That said, I wonder if your low setting could be adjusted. If you're at 6 and have an event that needs 12 to correct, it takes your machine a while to get to the needed pressure. Many people have had success by increasing the low pressure a tiny bit and leaving it there for a week or so, then increasing it a tiny bit more, and continuing that until the pressure stabilizes a bit. Just a thought.

cortez356 wrote:.Early on I did see some [apneas?] that were 13 but that was rare. Most seem to be 11 or 12 max. I could try 13 for a week and see what happens?

Thanks

Bob

I'm confused: Did you see apneas with FLAGS that said 13, 11, or 12? The numbers on the each flag is the lengths in seconds of the corresponding apnea. Or are you trying to say that the apneas occured when the PRESSURE GRAPH was indicating a pressures of 13 or 11 or 12? You cannot tell the PRESSURE the machine was running by looking at the EVENT graph by itself. You have to look at both the EVENT graph and the PRESSURE graph at the same time.

Sorry for the confusion. No those numbers were the highest pressure I reached as shown in the statistics. For a few eeks I ws watching both the minimum and maximum to see if I should change my pressure range. But first I have to get my leaks minimized as some of those high pressures could occur when there are leaks.

Bob