Managing flow limitations
Hi Everyone,
I've been using CPAP for around 3 years now with an untreated AHI of 7.5 and a treated AHI under 1. Initially I was on pressure 5-15 with EPR=1, but during the pandemic I got tired of waking up a lot and started using OSCAR to adjust my settings.
For the last several months I've been on fixed pressure of 7.6 with EPR=3. I have some nights that are great and others that are spotted with half a dozen RERAs and the occasional Obstructive or Hypopnea. From the machine reported numbers I should be doing great but I'm still tired and some nights I wake up a lot.
When I look at OSCAR I see that I have a lot of minor flow limitations off and on throughout the night and usually have a few bursts of high flow limitation. Maybe this is part of the reason I'm still tired? Should I try different pressure settings, or is a BiPAP what I need to get more pressure support?
Here's an example of a night where I didn't have a lot of events but still woke up exhausted
Zoomed into some flow limited breathing
Zoomed into a CA
Any ideas? Thank you!
RE: Managing flow limitations
Welcome to the forum,
Yes flow limits do seem to be a problem. I'd consider a range of something like 8-15 and see if that helps. Post an OSCAR and tell us how you feel, a critical summary of fatigue or not, if therapy is helping, etc.
Another thing to do is post a redacted sleep study. You should have a detailed copy anyway in your personal health file. HIPAA law permits your request for a copy to be granted. There might be things revealed there that's not currently addressed.
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEBSITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
RE: Managing flow limitations
Welcome to the forum
On the CA I think you were holding your breath. Following that looks like arousal, even a bit before that CA. See how your BR/Breathing Rate slowed down and became more irregular
On the flow limits I'd suggest a higher PS, but you are maxed out at EPR of 3 so increase your min pressure by 1.
But do note which settings feel better and why. Your numbers are excellent so do not chase numbers.
RE: Managing flow limitations
The period of higher flow limitations all occurred around the same time and based on your description it sounds like that is usually the case. This might be a positional issues (tucking your chin or something like that). I get some similar looking flow limitations leading to RERAs when my chin is tucked (if I move too far forward on pillow etc).
RE: Managing flow limitations
Thank you both. I’ll try increasing my pressure as you detailed to see if that helps. Last time I tried going above 7.6 I had a lot of aerophagia issues that would also wake me up but I’m willing to try again to see what happens and collect more data.
RE: Managing flow limitations
(05-25-2021, 08:34 PM)fishfinderG Wrote: Thank you both. I’ll try increasing my pressure as you detailed to see if that helps. Last time I tried going above 7.6 I had a lot of aerophagia issues that would also wake me up but I’m willing to try again to see what happens and collect more data.
How long ago was it that you had aerophagia?
Sleepster
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
RE: Managing flow limitations
I had aerophagia bad 3-4 months back when I was experimenting with fixed pressures above 7.6. I also get it from time to time even now if I’m having heartburn. Whenever I have heartburn or drink it seems much more likely to cause aerophagia.
RE: Managing flow limitations
It could be you need to go back to a pressure range so your higher pressure setting isn't active always. It only goes up for events.
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEBSITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
RE: Managing flow limitations
Adjusted my pressure to be 7.6-9 and kept EPR at 3. Woke up a few times during the night but overall this first night does look a little better in terms of flow limitations, although AHI was slightly higher than what I normally see. Did not have aerophagia which is a pleasant surprise given past attempts at higher pressure.
I'm going to try these settings again tonight.
RE: Managing flow limitations
Your apnea occurred at lower pressures, higher AHI had nothing to do with the new settings.
You had one moment where it looked like you were going to have higher flow limitations and the increasing pressure may have helped. I would consider raising max pressure a bit more even. The machine will only use a higher pressure when it needs to and for example last night was only only at 9 cm for around 10 minutes.
