[Diagnosis] String of OA and UA Events

[hobbycamguy]

   
Thankful for this forum and all of the help and knowledge provided so far.

Is someone able to explain the string of obstructive and unclassified events shown in my screenshot? Have been on APAP for almost two months now but I've never seen this behavior before...

Thanks!

[Heracles]

Hi,

Leaks are the main problem here if you ask me... See how they increase when pressure itself increases ? The leak rate also goes way above what the machine can sustain. As such, it does not provide actual therapy anymore...

[hobbycamguy]

Thanks, Heracles. That makes sense.

[Sleeprider]

Hobbycamguy, the clustered obstructive events are typical of what we often call "positional apnea" or chin-tucking. It usually results from your head tilting forward causing an obstructive curve in the airway. This can happen on your back or side, but is very common. The cluster is caused by obstruction of the airway with periodic arousals that allow the sleeper to clear the airway, and resumption of sleep. In this case there is recovery breathing followed by increasing airway resistance and decreases in respiratory volume to the point of apnea. We often see arousal prior to apnea and a series of hypopnea or RERA as well. This appears to be an isolated incident over 7 minutes and relatively event free time for the remainder of the night. The increases in leaks during this episode show changes in body position or a physical leak caused by your mask hitting your chest, shoulder or a pillow and becoming partially dislodged.

Read the wikis on positional apnea and soft cervical collar linked in my signature links. You will quickly recognize the pattern and understand the problem. I don't think you need to do anything as long as this remains an isolated or infrequent problem.

[hobbycamguy]

Wow...thanks, Sleeprider. That explains it. I'm using a pretty firm pillow right now which is probably not helping with chin-tucking or mask seal either. Fortunately, I haven't seen this behaviour on any other nights so far.

And thanks for the links...an amazing amount of info in those wikis. This is quite an interesting journey....

[Heracles]

Hi,

Indeed, such a pattern is --typical-- of positional apnea and it is --usually-- caused by the head tilting forward. Also, when it is the case, pressure is usually unable to fix it. But for this like for almost everything else, there are exceptions or different cases.

Here, my girlfriend had such a pattern once. A terrible session where she scored an AHI of 129 during the worst hour. Still, it happened only once despite she always sleep in the same position. Also, it happened when her APAP reached its maxed pressure allowed and never happened again since we allowed for a higher pressure. We since discovered the why about this. It was caused by her medication. She takes a muscle relaxant (baclofen) at a pretty high dose and her muscles ended up a little too relaxed. That is why pressure was able to fix it.

Of course, medication is probably not the only exception for such a pattern and it is always good to check the most common cause before looking at the more exotic ones.

Good luck improving your own situation,