ASV pressure question

[tuzacat]

Hi, Folks, there have been some changes in my sleeping patterns lately so I have started to play with settings on the ASV machine to see if I can solve my problem which is multiple arousals during the night. These can be from 1 to 7. Usually I will wake up about 3 -4 hours after falling asleep and on occasion have a problem getting back to sleep.

I have lost a lot of weight recently. 25 pounds since the beginning of May and 35 since Christmas. I have had major insomnia issues for many years - pre weight gain, post weight gain, pre cpap therapy, post successfully treated therapy. I often have had to take multiple supplements and drugs just to get myself to sleep and to keep myself there. Recently, however, much to my surprise, I have been falling asleep without having to take anything - pretty much right away. This is wonderful for me! The few times I have had to take something in the past couple of months it was a reminder of how terrible I felt in the morning and throughout the day with the drugs in my system , so I don't want to go back there.

Currently, I am using the Dreamwear FF mask which has been so comfortable compared to masks I have used in the past. After the break-in period my AHI has been consistantly from 0-.2. This is just my machine readings. I haven't had much success with Sleepyhead and Encore is so sluggish at this point I've stopped trying. However, I'm going to try to delve into Sleepyhead this weekend and figure some of this out so I can get some feedback from the experts on here. (I'm getting re-roofed this week so life is a little chaotic.)

In the past month or so I started to have issues with gas pain. It took a while but it occurred to me that what I was experiencing was aerophagia. I haven't had that since I initially started cpap in 2009 and it seems to be manifesting differently so I didn't recognize it. As a result I decided to start lowering my pressure. So far, I've gone from 12.5 to 11.5 - at .5 increments -waiting close to a week between adjustments. Less gas pain but still have some, AHI still 0-.2, still waking up. I feel I need to go lower.

Here are my initial questions:
1) Would just having the pressure too high cause the wake ups?
2) If the gas stuff is aerophagia even though it doesn't feel like I'm swallowing air (it feels more like I'm getting too much air and then gas pains during the day not at night) could that be the cause of the wakeups?

Any thoughts would be appreciated!

Best,
Sandra

[zonker]

bump

[JDS74]

Could you please list your pressures?
My sleep doctors suggest that the minimum difference between EPAP min and IPAP max by about 10 cmH2O or so.
This number is important so that while a central is being responded to, the effect of the ventilator mode is retained.

I'm currently living with less that that but that is one result of my severe pneumothorax of about 3 weeks ago. The doctors are very concerned that my previous therapeutic pressures that allow a EPAP min of 15 and IPAP max of 25 cmH2O would put too much strain on my lung. As a result, my numbers went crazy with centrals running to 6 or more per hour and the system being unable to treat them properly. Its one of those trade-offs in life.

Back to your original question, sudden shifts in pressure such as an ASV can do in responding to a central event can disturb some people.
It would help you to understand what is going on if you can look at the wave breathing data your machine produces and learn to link the change in breathing pattern from sleep to awake and then see if the wake event comes soon after a central event the machine was responding to.

It takes a while to get used to seeing the patterns and recognizing the arousals, awakes, and ongoing sleep patterns.

[tuzacat]

Hi, JDS74, thanks for your response. My current Epap min is 11.5, Epap max 15.5, PS min 6, PS max 12.5, Ipap 17.5, Max pressure 25. Is the max pressure the same as max Ipap? When I break into the settings and change things I'm not seeing anything that says Ipap but when I wear the mask the monitor says Ipap 17.5. I think I'm in the range you are talking about but I'm not sure.

The original prescription when I was put on the ASV was Epap min 8, Epap max 12, PS min 6, PS max 17, Max pressure 25 - doesn't say anything about Ipap. The problem was
I was gulping so much it was keeping me awake. As far as I can remember (it's been a couple of years since I saw the doctor) I only moved the the Ipap pressures and I told the doctor about it and he was ok with it. But I see now that PS max went from 17 to 12.5 - I must have done it but I don't know why. It's possible when I changed the Epap min to 12.5 I accidentally changed the PS max to 12.5, too. Do you think I should put it back to 17?

I was planning to bump the Epap down to 11 tonight to see what happens. Maybe I shoud work my way back to the original settings. I was wondering if I needed to make an appointment with the doctor since I lost so much weight.

You know, looking at those wave forms and graphs is really Greek to me. Even when folks have pointed things out that I should be looking for I don't see it or understand it. I don't think I will get proficient at it but at least I can download the newest version of Sleepyhead and see what I can see.

I really appreciate your thoughts!

[tuzacat]

Well, I was able to download Sleepyhead and organize the files for for a screenshot but I can't figure out how to make a folder to put the screenshot in so I can copy and paste the link. I will try again tomorrow.

[tuzacat]

Here is last night's sleepyhead screenshot. There are a lot of snores!

screenshot-20180718-232147.png (78.32 KiB) Viewed 998 times

[tuzacat]

Here is last night.

screenshot-20180719-081933.png (77.68 KiB) Viewed 983 times

[tuzacat]

For some unknown reason the flow chart for today isn't there on sleepyhead.

[zonker]

For some unknown reason the flow chart for today isn't there on sleepyhead.

be sure the sd card is inserted. and make sure it's unlocked. it should write to it then.

[tuzacat]

Thanks, Zonker! I found the SD card in the computer this morning. I stuck it back into the ASV and then later imported into Sleepyhead. After reading some of the Sleepyhead tutorials I think the issue was it wasn't in the machine all night. I have never locked or unlocked the SD card. It came with the machine so I'm not sure if locking or unlocking is an option. I will do some research to see if I can figure it out.

Since they have been pounding on my roof all day and I needed to be here I have spent some time reading some of Pugsy's, and also some Sleepyhead, tutorials. I was able to look at the flow graph and zoom in. There were some flow limitations numbered from 8 -12 but not always at the time I was snoring. I took a look at my FitBit to see if they were happening just prior to the wake-ups. Unfortunately, the FitBit is not as precise as Sleepyhead so I didn't see anything like that. It seems I was in a deep sleep stage when a little series occurred but another time I was in a light sleep.

I also looked back at the higher settings and I saw I was snoring then as well.

I'm planning on keeping track for a while to see if I can decifer anything. If anyone has any thoughts, please, feel free to chime in - although I may not have enough info yet for anyone to have an opinion.

[palerider]

I think the issue was it wasn't in the machine all night.

The good data is written directly to the card, so if the card isn't in the machine, then nothing gets written anywhere.

[tuzacat]

Thanks, PR. It's a little easier to navigate Sleepyhead this time around, but it doesn't help much when I leave my card in the computer. I'm going to monitor for a couple of days and hope to spot something. It's amazing to me how complex the program is and I'm in awe of someone who was able to conceive of it and bring it to fruition.

[palerider]

Thanks, PR. It's a little easier to navigate Sleepyhead this time around, but it doesn't help much when I leave my card in the computer. I'm going to monitor for a couple of days and hope to spot something. It's amazing to me how complex the program is and I'm in awe of someone who was able to conceive of it and bring it to fruition.

It might help to get in the habit of putting the card back into the machine as soon as you do the import, before you spend some time tinkering with sleepyhead... that way you're less likely to forget about it after looking at stuff.

[tuzacat]

Good idea! I haven't pulled the card out of the machine in quite some time but now that I have new motivation to delve into this a little more I guess I need to develop a new habit.

[JDS74]

My current Epap min is 11.5, Epap max 15.5, PS min 6, PS max 12.5, Ipap 17.5, Max pressure 25.

Those numbers sound like Philips-Respironics ASV numbers. So, assuming that's true:

In a PR machine the controlling number is the IPAP Min. It sets the minimum pressure the machine will generate.
The PS Min sets the minimum IPAP pressure it will generate and also the maximum IPAP in normal mode.
Max Pressure sets the upper limit on IPAP when the machine detects and tries to treat a central event (CSA).

So, With your numbers here's how things work out.
EPAP floats from a minimum of 11.5 cmH20 to a maximum of 15.5 cmH2O.
IPAP floats from a minimum of 17.5 cmH2O to a maximum of 25 cmH2O (the smaller of Max Pressure and the sum of EPAP Max + PS Max which in this case is 27.5)

Both EPAP and IPAP adjust independently of each other but require a minimum separation of 6 cmH2O be maintained.


Back to your question about what is happening just before you wake during the night.

If you drill down within the SH report on the graph that shows breaths, the graph will show regular and even in and out breathing when you are just sleeping and nothing else is going on.

OTOH, when you are awake, the graph will be more irregular with higher peaks than "just normal sleep". Arousals not resulting in being actually awake, just show a distorted breathing graph for a minute or three followed by returning to the normal, regular breathing patterns,

An arousal or wakening looks like normal sleep (usually) followed by and abrupt change to very irregular breathing.

If you can use your FitBit graph to find the approximate time of an arousal (I know its hard to synch the CPAP data and the FitBit data) then you know about when to look in the SH data, probably within fifteen minutes of so. In your case as well as mine, throw in CSA events which distort the SH breathing graph somewhat and sometimes occur just before and arousal so you will need to look out for them. Event flags in SH will allow you to locate and drill down to the associated breathing graph so you can become familiar with what they look like. (as an aside, all this is much easier if you can use Encore Pro for the breathing graphs since they are shown in full detail, 30 minutes per page of report for the whole session. No need to do the drilling down thing. SH provides other quite useful ways of looking at the data so the best of all worlds is using them both.)

Here is what my normal sleep looks like:

Normal Sleep.tif (395.05 KiB) Viewed 896 times

Here is an arousal:

Arousal.tif (393.38 KiB) Viewed 896 times

The arousal is on the right followed by a junk hypopnea flag.

Here is what a really messy series looks like:

Centrals.tif (807.43 KiB) Viewed 896 times