Interesting sleep study!

I have been a faithful hoser now, for a little over a year. Earlier last month, I visited my sleep doctor for a checkup, and some advice on what we should try next. But first, a bit of background.

I was diagnosed with severe sleep apnea (AHI >=96) in March of last year. In April, I had a split-night sleep study done. They had a very challenging time titrating me, due to the emergence of central apneas when they applied anything close to an effective pressure. I was prescribed an APAP, with an intiial range of 10-13. The doctor knew from the get-go I planned to manage my own therapy. I purchased an DeVilbiss IntelliPAP Autoadjust machine, and a Quattro mask. I quickly changed to the Hybrid mask, which I use to this day.

Initially, there was a dramatic improvement in my sleep and wakefulness at 10-13. No centrals to speak of, either. But my average AHI was about 7. Over time, I worked my pressure range up to 13-17, with little improvement in results. My therapy vaires greatly from night to night with no apparent reason (and this includes leaks). In October of last year, the sleep doctor recommended I work towards a pressure range goal of 14-18. I was unable to achieve this with the IntelliPAP due to a tendency it has to 'run away' with pressure, on some patients. I still felt a lot better, but not as good as I did at first.

After reading about different machine algorithms earlier this year, I decided that part of my problem might be that the IntelliPAP, which is not an aggressive machine by nature, might be aggressive in the wrong way for my pressure needs. So, I ended up investing in a Resmed VPAP Auto 25. I used this machine as a straight APAP at 13-18, and then switched to 14-18 in late April. This is a wonderful machine, and very nice to breathe against. But, I seemed to be sleepier with this machine. Average AHI has improved to a range of 5-6, but I still see a lot of variation day-to-day. I have the Rescan software, but have been able to read the machine since my smart card mysteriously disappeared in April. They have since been discontinued by Resmed (they have really become user-hostile!). When I did look at the data, there was nothing really exciting to see, other than the machine rarely really cranked up the pressure.

Anyway, my sleep doctor (which is different each time ) now recommended a new titration sleep study. Although he doubted it would help much in this case, but because I have a bilevel machine, we decided that the study should include this as an option.

At the sleep study, which was last Thursday evening, I discussed things with the technician. The machine they were to titrate me on was the lab version of the Respironics BiPAP SV Advanced. The tech was ready to try anything from straight CPAP to adaptive servo ventilation (ASV).

In any case, it was a very rough night. After the first hour, where I slept nicely, everything went wrong. By then, the tech had me on CPAP at about 10. I awoke, and my mask started to leak. Remembering the fuss from the previous study about messing with my mask, I just let it leak (it was not a perticularly severe leak, so i just let it leak), and tried to fall asleep. Although I could feel myself trying, I could not fall asleep. The tech (as I later found out) increased the pressure to 14, with a A-flex of 1. (I could tell it was A-flex he was using and not BiPAP). As it turns out in retrospect, I should have corrected the leak, and tried to sleep. But, instead, I never could get back to sleep.

Next phase was to try Bilevel. This was my first experience with bilevel therapy, and it did not seem like it did anything for me at all. The tech was using an EPAP of 10, but I never did find out what the pressure support (IPAP-EPAP difference) was. Was probably 2, and certainly no more than than 3. I was underwhelmed. And, I never did sleep. One thing thing I did experience that I had never actually noticed to any extent, was sleep-onset central apneas. These seemed to last (to me, anyway) only 3-5 seconds, and were accompanied by a vivid thought of some sort.

Then, the tech switched me to ASV, with an EPAP of 8 (CPAP mostly, but he did try bilevel again for a while), and a pressure support of 15. Very interestingly, the machine became quite busy. I would notice sudden pressure increases (which is how I figured out it was in ASV mode), and soon figured out that they were correlating with sleep-onset centrals. Like I had observed earlier, I seemed to have a really strong thought or vision just before a pressure burst, and these bursts tended to wake me up. Eventually though, I became somewhat (but never totally) used to them.

Finally, I did fall asleep, and had one particularly memorable dream. (The tech told me I actually was in REM on two different occasions). But eventually, I was awake again, and never did really fall asleep again. By now, I was starting to get sore from laying on a mattress very different from my own.

By the time the study was done, I had been in bed for 10 hours, with just one bathroom break 5 hours through.

What does this all mean? Did the CPAP portion fail because higher pressures were never explored? Is Bilevel not for me because I have no trouble breathing against pressures as high as 18 cm (the highest I have tried). Did ASV really help, even though I don't have the traditional problems that ASV is usually reserved for? Was EPAP perhaps too low during the ASV phase?

I have a followup appointment on June 10th. It should be rather interesting!

my goodness, that was quite an adventure!

Cant wait to hear the results of all that happened.

Goodness, so many pressures and machines..

My experince was much more "white bread" than that..

good luck!

With my experience in titrations, it sounds like your tech was having difficulty titrating you. When a patient has difficulty sleeping, the readings can show irregular breathing which is throwing the tech off. That irregular breathing however is normal when somebody is in and out of sleep so much. The breathing events are called "transitional" which happen when someone transitions from wake to sleep or vice versa. Another titration study may be in order.

Did you use your mask? The more comfortable you are the better. Good Luck!

sleepmba wrote:With my experience in titrations, it sounds like your tech was having difficulty titrating you. When a patient has difficulty sleeping, the readings can show irregular breathing which is throwing the tech off. That irregular breathing however is normal when somebody is in and out of sleep so much. The breathing events are called "transitional" which happen when someone transitions from wake to sleep or vice versa. Another titration study may be in order.

Did you use your mask? The more comfortable you are the better. Good Luck!

Thank you. I am indeed aware that some irregular breathing can occur during sleep transitions. And indeed, I can tell you firsthand that this was indeed happening. Your thinking that another titration may be in order is not far off what I have been thinking as well.

I did indeed use my own mask, and other than the leak I mentioned (which I could have easily dealt with), I had no mask issues. Indeed, the low pressures being used were wonderful from a mask perspective!

timbalionguy, welcome to my world! unfortunately your sleep study sounds more like one of my torture tests than anything.

a couple years ago i had HORRIBLE problems with sleep onset central apneas during a sleep study. the owner of the lab was there to try to help. he came in and chided me for not falling asleep. give me a break! it's not as if i WANT to stop breathing !!!

during my next to last last sleep study i had so many problems the sleep doctor wanted to send me back for yet another study on bi-level. at that point, i put my foot down and ask "what will change?". i got very, very clear (and was almost in tears at that point because i was getting so little sleep) that the central apnea was my biggest problem. finally, a sleep doctor listened. he scheduled another sleep study with ASV.

but as you discovered an ASV titration is an "interesting" experience. i am not somewhat used to the sudden pressure increase. in fact, for the first time in years, i can fall asleep without fear that i will stop breathing for so long that i will awaken with SEVERE headaches.

i sure wish i had some wisdom for you. it sounds as if they might need to get a baseline study - where they don't try to intervene - to see what actually happens. then they can try another night with a specific type of titration.

but you do have my best wishes as you proceed toward some semblance of better sleep.