3rd Sleep Test: Auto SV Study

My sleep study showed 28 AHI with my Oxygen level going down to 81 when I'm on my back and in REM. It said I have moderate OSA. I have a copy of the original sleep study.

I had the titration study the next week and they had my settings at 20/14. The doctor that reads the titration study was on vacation last week so I waited until today to hear from the office. The nurse called to say that the doctor is uncomfortable putting me on a bi-level so he wants me to go back in again to do an Auto SV. She said they want to see my Oxygen level above 88. With the settings at 20/14 my AHI was still around 20. So now I wait until the hospital calls me to set up an appointment. BTW, if I don't hear anything tomorrow morning, I'm calling them to get it scheduled.

Now...should I worry about falling asleep? LOL. What exactly is an Auto SV study? How is it different than the titration study? Did anyone else have to do it 3 times before getting on a machine? What are they telling me?

I have been having trouble breathing deeply and hiking up hills I get out of breath real fast. I am on Flovent for asthma and will be going through some allergy testing the first of next month to find out what exactly is the cause. I know I have chemical allergies, including bleach, cigarettes, perfumes, silicone, and the list goes on. My family doctor sent to do the sleep study originally trying to figure out what is causing my breathing problems. My husband and I were both surprised at the results.

In the meantime, I'm reading everything I can get my hands on. This site is wonderful. Thanks everyone.

Does your original diagnostic sleep study happen to mention many centrals?
If not, then this

Ogeo wrote:with the settings at 20/14 my AHI was still around 20.

You may have developed Complex Sleep Apnea and hence the need for ASV machine
see this video
https://www.youtube.com/watch?v=CU-XTcf ... e=youtu.be

Auto SV machine is just another type of machine that can be used for special circumstances. The high end fancy and most expensive machine used to treat both centrals and obstructives or both.
A sleep lab titration study is the best way to find optimal pressures with this machine as it has more potential adjustment settings.
Finding the right pressures on a DIY basis can be done but I don't advise it unless no other way. To many variables especially if low oxygen is of concern.
Sleeping with the ASV really isn't all that different than the AutoSet....the ASV just responds quicker and can go higher with its responses.
I am using a S9 Adapt ASV type of machine right now...I find it quite nice myself.

Ogeo wrote:My sleep study showed 28 AHI with my Oxygen level going down to 81 when I'm on my back and in REM. It said I have moderate OSA. I have a copy of the original sleep study.
...
What exactly is an Auto SV study? How is it different than the titration study? ...

An Auto ASV study is another titration study but designed to get pressure settings for an ASV machine. There are more than just IPAP and EPAP settings with an ASV machine. With the prior titration using 20/14 as pressures for a bi-level machine and the AHI still elevated, it seems as if you are having quite a few central apneas and that they are contributing to your low SpO2 values during the study.

Good for your doctor calling for an Auto ASV study to see if this different type of therapy can resolve the AHI issue as well as the low SpO2 issue. Having asthma as well as sleep apnea complicates what is going on. If possible, get a copy of the first titration study as well as the ASV titration study so that you can see what is going on as well as for your records.

By way of explanation, when you have an obstructive event, raising the IPAP pressure (inhale) opens the airway and lets you breathe. When you have a central event, the airway is already open so a bi-level machine has no tools to help you with breathing. The ASV machine, on the other hand, can both increase the IPAP pressure while dropping the EPAP (exhale) pressure. That inflates your lungs (and chest) on the inhale side and allows for normal chest relaxation to provide assistance on the exhale side. This is a kind of ventilator action and breathes for you until you begin to take a breath on your own when it switches back to a bi-level mode and continues.

Pugsy wrote:Does your original diagnostic sleep study happen to mention many centrals?
No, I went back and read it again and couldn't find anything that suggested centrals.

You may have developed Complex Sleep Apnea and hence the need for ASV machine
see this video
https://www.youtube.com/watch?v=CU-XTcf ... e=youtu.be
Thanks for the video. That was interesting and informative.

Sleeping with the ASV really isn't all that different than the AutoSet....the ASV just responds quicker and can go higher with its responses.
I am using a S9 Adapt ASV type of machine right now...I find it quite nice myself.

Thanks for the feedback.

Good for your doctor calling for an Auto ASV study to see if this different type of therapy can resolve the AHI issue as well as the low SpO2 issue. Having asthma as well as sleep apnea complicates what is going on. If possible, get a copy of the first titration study as well as the ASV titration study so that you can see what is going on as well as for your records. I have already asked for a copy but don't know when I'll get it. I might have to ask again as I was asking before the doctor had seen the titration. It will be interesting if it shows centrals since my original sleep study didn't say anything about it. Also even though both the sleep study and the first titration were done at the same place, there was two different people who did the studys. I wonder if that makes a difference?

By way of explanation, when you have an obstructive event, raising the IPAP pressure (inhale) opens the airway and lets you breathe. When you have a central event, the airway is already open so a bi-level machine has no tools to help you with breathing. The ASV machine, on the other hand, can both increase the IPAP pressure while dropping the EPAP (exhale) pressure. That inflates your lungs (and chest) on the inhale side and allows for normal chest relaxation to provide assistance on the exhale side. This is a kind of ventilator action and breathes for you until you begin to take a breath on your own when it switches back to a bi-level mode and continues.[/quote]Thanks for all the info.

If the second study shows centrals later in the evening/early morning but not in the early evening, that may be an indication of complex apnea brought about by the increased pressure. In any event, getting the study will be interesting reading and give a better insight into what is going on.
Hope your ASV titration study goes well and you can get going with treatment.

I decided to call this morning to the hospital sleep lab and was able to get my second titration study scheduled next week. At first she wanted to have in in over a month and I asked for something sooner. Lo and Behold there had been a cancellation so I am going in next Thursday. I will definitely get a copy of both titration studies to compare them.