[Treatment] AHI consistently increases through the night

[RTurner]

Hi everyone:

So thankful to have found OSCAR recently and this forum! In looking at my data, my AHI pretty consistently is fairly low for the first 2-4 hours, but then jumps higher, often way higher in the 4-8 hour range. Below is my data from last night. You can see my average AHI is 25, but it was less than 15 for the first three hours, then spent much of the rest of night at 30 or higher, then shot up further at the end to 56. This is a typical pattern for me, but lower averages overall. My 30 day average is 14, but often shooting to 40+ late in the night.

Could this late-night increase in AHI be causing my struggles with fatigue?

Any thoughts would be greatly appreciated. I'd like to schedule an appointment and show this data to my doctor, but will they believe it to be valid?

Thanks,
New member Ray

[Crimson Nape]

Hi RTurner!  -  

It seems you are having image posting problems.  Please review the links in my signature for posting screenshots here.

If you are using the AHI graph in the Daily screen, ignore it.  It really doesn't provide any useful information.  Without seeing your report, I am just guessing that your apneas are positional related.  This is based on your events only occr at certain points in your sleep and not spread out for the whole session.  

Again, this is just a guess.

- Red

[PaulaO2]

Also keep in mind the math that goes into figuring out the AHI. It is apnea events (obstructive and central) plus hypopnea events divided by time. And while it would seem the longer the sleep, the lower the AHI, that is not always the case. There are far too many factors that got into it. Such as position while sleeping, depth of sleep, etc.

[RTurner]

   
   
   

Thanks for the replies! I blame sleep apnea for my inability to follow the directions for uploading photos!  

My big question is what is happening to my health in the last 2-3 hours of sleep if my avg events over that time-frame is often 30+, sometimes higher? Would I be better off setting an alarm at the 4 hour mark and just stop using therapy? What is causing my events to go up a lot towards the end, consistently? I've been using a sleep machine since 2004 and the current machine a few years on the vauto setting. Originally, I had a machine with a backup rate, but it died and the next sleep study showed I didn't need the backup rate, but I am wondering if may I do.

Thanks so much for taking the time to review my post.
Ray

[OpalRose]

Hi Ray,
First, I'll address the Positional Apnea.  Note the apneas that are clumped together.  
This happens when you are sleeping in a way that cuts your air supply, which we call "chin tucking".   This can occur on your side or back.  If you sleep on more than one pillow, or a pillow that is too tall, it can cause your head to tilt forward, thus cutting off your air.  Kind of like a kinked hose.  Many here have found that using a soft cervical collar has helped.  

Read these articles to get a better understanding.

http://www.apneaboard.com/wiki/index.php...tucking.29

http://www.apneaboard.com/wiki/index.php...cal_Collar

You said you previously used a machine with a backup rate.  If that's the case, your doctor must be aware of your Central Sleep Apnea.  Changing to a VAuto will not treat Central Sleep Apnea.  Although it's an excellent machine and has a couple settings that may help.   What is the Trigger Setting on your AirCurve VAuto?  The default setting is Medium.
Try setting it to High or Very High and see if that helps.

[Sleeprider]

Completely agree with OpalRose, and will just add that the nature of chin-tucking is such that the effort to take a breath through an obstructed airway can result in a central apnea flag. We don't know much until you deal with the root cause of the clustered apnea. Please revise chart organization to show events, flow rate, pressure or mask pressure, flow limitation and leaks.

[RTurner]

           
Thank you all for the great replies! I will definitely get a collar ASAP and check the trigger settings on my machine. I have also attached more photos from last night so you can see all the fields referenced.

Thanks,
Ray

[Sleeprider]

Rturner, if you have the results form any sleep studies, they might help us to see if the central events flagged in your results existed before CPAP therapy. The fact that your are on Vauto suggests that you did have centrals, and are on a Vauto, which you will fail, before being put on the therapy that can treat central apnea. ASV (adaptive servo ventilation) is the gold standard for treating central apnea. It's very important that we see your sleep study results to give you the best strategy to deal with your medical team.