What does Oscar show just before I wake up?

[Anna Bee]

This is my first post and I am grateful to the group for taking the time to read it. I am in the USA, female, 50 years old, normal BMI. My journey begins 10 years ago when I was frequently waking at night, and I had TMJ, chronic neck pain, sinus problems, mood problems, and migraines that occurred only at during the night. I got a turbinate reduction and botox specifically for the migraines and all these issues all got better. Fast forward to 2023 and I had a horrible case of rhinitis following which I started waking up scores of times per night. Sleep testing showed an AHI of 9.37. I had another turbinate reduction and it helped immensely. My AHI dropped to 2.4 with all my events clustered in REM sleep, and 79 arousals. DISE testing showed collapse of tongue and soft palate. I know my numbers don't inspire compassion. Lots of people on this board would kill for these stats. But I am still exhausted every day. I am now on Gabapentin and Modafinil to manage my sleep maintenance and daytime exhaustion, and both drugs come with unpleasant side effects. I have tried very hard to succeed at CPAP/BiPap compliance and just keep failing. I usually last 1.5 hours before waking up feeling like I am suffocating, and throwing my mask off. My previous sleep doctor had me at 11 Inspiratory and 7 Expiratory. I consulted with another doctor who measured my lung strength and resting CO2 levels (I have hypocapnia at rest). He urged me to drop my pressure settings down down to 4/3 and work my way up slowly. I did. Last night I slept 4 hours before waking up believing I was drowning. Based on my novice research I believe that I have a very low arousal threshold, narrow upper airway, problems with high loop gain, sensitivity to changes in my CO2 levels. My goal right now is just to get all the way through the night on my BiPap machine. So, I am sharing with you some screen shots of just before I woke up. Please tell me your impressions of what is going on. Why do I feel like I'm suffocating? Thanks!
       

[Sleeprider]

Anna Bee, you are using the lowest possible pressure on your CPAP machine. It would really help if you would post the full-night Details chart (see Organizing Your Oscar Chart in my signature links). Although there is some flow variation in your chart, I don't know that it is remarkable. The spike at 03:34 shows a breath-hold. This is common when a person rolls over in bed and other reasons. The pause in breathing at 03:51:25 is just a normal long exhale, and you appear to swallow and finish the exhale then resume breathing normally. These do not appear to be arousals.

You feel like you're suffocating because your pressure is too low to even use exhale pressure relief (EPR), and with a full face mask, you are simply not getting enough airflow. Please consider raising pressure to 6.0 and using setting 1 or 2 EPR.

[Anna Bee]

Thank you. That stands to reason. I will refer to the "Organizing you Oscar Chart" instructions for future.... The little green leak rate indication that goes on during these moments. Are they really leaks? Or, are they artifacts of the changes in my breathing?

[Sleeprider]

With only 4-cm of pressure, it's possible your device is just unable to sense pressure in the mask. Seriously, all your problems are related to the improper setup of your CPAP and pressure being too low. If you're awake to see the CPAP display when these events occur, you're not sleeping and they are not sleep related breathing disorders.