Recently started CPAP, need help optimizing

[NowiREMember]

Hi, I'm a male in early 20s with BMI of 21 who just started CPAP 5 days ago. Excited to begin therapy after experiencing a delay of several weeks due to COVID. I've been lurking the forums the last few days to help myself get acquainted with my machine. It has been a HUGE help for me. I am now looking for further help to optimize my therapy as best I can.

Sleep study:
Haven't received official report yet, but I'm working on getting it. Here's what I know.

-AHI in upper 20s
-AHI during REM sleep increased to upper 40s
-Diagnosed as OSA, minimal to no central events
-Lowest O2 sat @ 90%

Therapy:

Day 1: Brutal, with a lot of central events. Stopped using after less than an hour.
Day 2: Upped the min pressure from 4 to 7 due to feeling of suffocation.
Day 3: Lowered min pressure from 7 to 6 due to high amount of centrals.
Day 4: No change
Day 5: Lowered FLEX from 3 to 1 to try to further decrease centrals.

Chart from Day 5:

   

Let me know if there's any other charts I should post. Thanks

[Sleeprider]

The actions you have taken to reduce CA events seem appropriate. It might help to see the results of your sleep test that brought you to CPAP. With your age, and BMI, obstructive apnea seem unlikely, and we often see people like you diagnosed with obstructive sleep apnea, but in reality, the tests show more central and hypopnea or mixed apnea events. If you post the sleep study, please redact personal information.

[NowiREMember]

Woke up not feeling so great today. Numbers are also not as good as previous few days with no changes made. 

Sleep study (results slightly different than original post) and chart from last night posted below.



          

[NowiREMember]

AHI has been consistently going down. I've noticed a gradual improvement in how I feel over the last few days but still tired. Central events have really been going down, I'm guessing it's from becoming better adjusted to CPAP. I have a couple questions.

1. Is there a way to determine whether hypopneas are central vs. obstructive? My sleep study was predominately obstructive hypopneas so I was assuming that's what the hypos I see in OSCAR are.

2. Are there setting adjustments I can make to further decrease my hypopnea numbers?



Charts from last 2 nights:

           

[Sleeprider]

The RERA and flow limitations are obstructive, so I suspect your hypopnea are as well. With the Resmed machines we often use the bilevel pressure support of EPR to treat all of these problems that arise from flow limitation or upper airway restriction. With the Philips, the best tool is an increase of minimum pressure. To get a better look at these events, use the Events tab (under the date) to zoom in on the individual or groups of hypopnea. Use the slider at the bottom of events to zoom into a 2 or 3 minute closeup. If you see a lot of flat-topped inspiratory waves in the flow rate, that is the signature of flow limitation. If hypopnea is central, it will look like a gradual attenuation of the flow rate without the signature flat-top on the waves. Assuming obstructive, I would suggest increasing pressure in 1-cm increments and observe the changes. Somewhere between your current minimum of 6.0 and 9.0 you are going to see a change.