Complex sleep apnea occurs usually later in night

My doctor thinks I have complex sleep apnea and is doing another sleep study in a few weeks.

I use the sleepy head software. It reports very little obstructive apnea. Less than 2 usually. But I have high clear airway apnea. Around 10 to 20 score each night.

The thing is when looking at graphs almost always the clear airway comes mainly in 2nd half of night. Over 90 pct in second half. What does this mean ?

I would like to give you a simple direct answer, but with central apnea there seems to be nothing simple about it. One of the things I have noticed is that if I try to sleep too long, I tend to get more apnea, especially near the morning. I think that when you are waking up and going back to sleep that is conducive to apnea of both types. More pressure can generate more CA events. Is it possible that your machine is responding with more pressure toward the morning? It would be helpful to post a Daily Report screenshot to look at. On a PC, use the F12 key to save the file and then left click and drag the image file it saves in SleepyHeadData/Screenshots to the body of the message.

Hopefully below shows my graphs. I'm working on a Mac. I used to have 8-16 pressure on the machine and I was getting about double the clear airway apneas. I have now switched to just fixed pressure of 8 and get less clear airway and it happens in 2nd half of night ( or more towards last 1/4 of night ). I'm hoping that I can sleep long enough in the sleep study for the study to show this.

Central events can do that sometimes. A couple of weeks ago I had 2 patients who only get central events while they were on their back. However, the treatment (Bi-level of some sort) should work for them just the same.

If you have not already you may want to read the article at the link below. It comes from another part of the website where this forum is. In the article it suggests complex sleep apnea is more likely to occur in the non REM sleep period of the night. That may be an explanation as to why you are seeing different levels of apnea during different times in the night.

Complex Sleep Apnea