Hyperventilation only while using CPAP

[sarge21]

Hopefully someone can assist me with this. I have an appointment booked with my sleep clinic and will make one with my GP, but I'd like some insight into questions I can ask or things I can try before then.

The main issue, and what I know is as follows:

1) Oscar reports my respiration rate often hits 50+. I have confirmed this by audio recordings taken while sleeping
2) This seems to happen more often starting in the middle of the night to late morning
3) Some days this seems to happen very little, but sometimes I will spend a significant portion of the night at 50+ BPM (see the image titled dec 19.png)
4) I will sometimes, but not enough to form a correlation, awaken drenched in sweat
5) I will often wake from these episodes unable to fall back asleep, but extremely fatigued (more than normal) and a bit confused
6) I don't have any panic attacks or anxiety that I am aware of (unless it happens when I am asleep). I have no problem sleeping through the night with the full face mask
7) Last tests for diabetes was negative and other blood work was normal. No allergies.
8) AHI is usually between 0.5 and 4.5
9) I am 37 years old and 200lbs. I am approximately 20lbs overweight by my estimation. I lift weights and train at an MMA gym and exercise strenuously 3x per week and lightly 4x per week, but my diet is poor.
10) This issue has been going on since I got my CPAP, probably 2.5 years ago, but it seems to have gotten worse slightly about 1 year ago
11) I do not think I am rebreathing CO2. My mask vents work. In addition sometimes when Oscar reports long periods of 50+ breaths per minute, I have a coincidental mask leak.
12) I have turned off the pressure relief setting on my CPAP with no luck (I turned it back on after I confirmed there was no effect).
13) Although better with CPAP treatment, I still suffer from excessive daytime sleepiness even when I get lots of sleep, to the point that sometimes I  need to pull over and nap while driving.
14) There is a history of autoimmune disorders on both sides of my family. I am hyporthyroid, although I have been stable on my dosage for a long time and this has been confirmed by my doctor.


I have attached three files. One is a screenshot of Dec 19, as that was a pretty bad night. One is a history of my respiration rates over the last 183 days for context. One is a higher resolution view of what my breathing pattern actually looks like during one of these episodes. If there is anything else I can provide let me know and I will do so. Thank you to anyone taking time out of their day to look at this.

[Sleeprider]

Good job on the charts. Please include the Daily Sidebar F8 on at least the overview chart. I'd like to get the summary of your settings as well, but your concerns about hyperventilation appear to be well founded. In the close up of flow rate you are breathing at close to 60 bpm with well-formed even breaths at relatively high flow rate. So this is not the usual shallow breathing, but an actual increased rate with the same tidal volume that is cranking up your minute vent. Normally, we would expect to see this result in hypocapnea and central apnea, but that is not the case here.

You discussed that your mask vents are functioning normally. CO2 is a driver of high respiration rates so that is an important observation. While the mask vent is apparently working, it is also important that the anti-asphyxia flap property shunts expiration to the vent and prevents backflow into the tube. For that reason, the first thing I would do is replace the mask. If the problem continues, you have a backup, but it's an easy fix if it solves the problem.

Let me think about this one a bit more. I have seen high bpm from anxiety and irregular respiration, but this one is new.

[sarge21]

Thank you for your response. I have attached an the sidebar and settings for the day in question

[Matt00926]

Try increasing your min pressure to 7 or 8 and see if that helps. 4 is just too low and could be causing problems. Make one change and see. Then maybe adjust EPR after that and see.

[sarge21]

I'll mention the pressure to my sleep clinician. I'd like to note that the 50+ BPM issue happens seemingly regardless of the pressure at the time. Sometimes it occurs when the pressure is low and other times the pressure is high.

Also, sleeprider, the well formed even breaths appear to only happen sometimes. Other times, it is erratic or wavy (not sure how to describe it, but I have attached examples)

[JoeyWallaby]

Please post the flow limitation chart, you haven't included it in any of your screenshots.
Your settings say you have an antibacterial filter. Is that correct?

[Sleeprider]

That last closeup is the one I needed. You do need to change minimum pressure to 7.0, but much of the high respiration rate is because the respiration is so erratic leading into it. Volume is all over the place, and the shape of the respiration is so erratic the machine doesn't know what is inspiration and what is expiration. Following the chaos, in the segment at 9:18:30 you are breathing deep rapid breaths and then the breathing becomes periodic and looks like Cheyne Stokes without the apnea. I still don't know the cause, but I have seen the pattern in a member that hasn't been around for a while, Hojo http://www.apneaboard.com/forums/Thread-...#pid223896 I described his respiration as panting, and like yours it was all over the place. Ultimately Hojo resolved this problem with an Adaptive Servo Ventilator.

I'd like to see these flow-rate closeups cleaned up including the y-axis and adding a dotted line at zero. If you can show these different types of respiratory flow to your doctor or sleep clinician, it would be interesting to hear his interpretation. I think the sleep clinician may look at your AHI and conclude things are fine. If you don't get a solution there, I'd like to try some different approaches to your pressure, including trying a smaller pressure range like 6 to 10 pressure and see if things change if we turn off EPR. Things we need to rule out include movement like PLM which can disrupt the flow pattern as well. Your current pressure range of 4-20 are default self-titration settings and I suspect that these may be part of the problem.

[Too Sleepy]

Hello Sleeprider. I have the same exact issue and made my own post. Could you please share some insight?