Sierra

Happy New Year,

It looks like the three OA events were likely due to the pressure being lower. When you lower the minimum the ResMed slowly reduces pressure if you are not having any flow restrictions. Flow restrictions are not shown, but outside of the OA events it looks like they are keeping your pressure higher at times. I would guess that the OA event woke you up and the CA was just part of waking up.

All in all you have a pretty good balance of CA and OA events, with a reasonable total event frequency. If you are generally sleeping well, I think you are doing very well with your settings. You have made a very significant improvement from where you started with your first OSCAR posts. If the OA events start tending to be higher than the CA events, you might want to consider raising the minimum pressure some.

Overall your results are pretty good with an AHI under 1. It looks to me as if those CA events were most likely due to arousal events. You could consider lowering the minimum pressure to 12 to see if that helps. With not sleeping on your back, that may be ok.

Merry Christmas!

On that first event at about 4:10 I think just before the CA event you had a short OA event that did not last long enough to be flagged. When the machine determines that flow has stopped it starts a high frequency flow cycle. This is how it determines whether the event is a central or obstructive type. If it is obstructive then the pressure cycles up and down in response because the airway is blocked. If the pressure does not cycle up and down as much then it means the airway is open. In the 4:10 event by my eye the short period of cycling produces more of a pressure response than later when it gets flagged as a CA event. This would suggest you had a OA followed by a gasping and then drop of of breathing effort. While it appears to be a legitimate CA event, the trigger was probably the OA event. In both cases you can see the impact on the minute ventilation graph. It goes unstable prior to the CA event.

The second event is not quite the same. It looks like you just took a deeper breath and then the effort dropped off to another CA event. It is actually normal to take a short extra deep breath while sleeping. My wife does it on a regular basis every 8 minutes or so. I forget the name but it is considered normal. Your response to it was not quite normal though, and it ended up as a CA event. But, in the scheme of things not a real serious event. Here is what my wife's breathing looks like when she takes the periodic extra deep breath. In her case it does not result in any issue and the breathing carries on at a regular frequency with no events. The first event is right where the green cursor line is, and then you can see the subsequent periodic repeats of it. Notice that there is next to zero impact on her minute ventilation. It remains very stable. She has few issues with CA events (unlike me).

The CA events are unlikely to be caused by body position in my thinking. They are when you simply stop breathing and there is no flow restriction. For many they can be caused by the pressure. Higher pressure tends to cause more central events. However, on this night your CA events seem unrelated to pressure. You went up to 18 cm and there were no CA events associated with that pressure rise. The CA events just before waking up often tend to be because you are waking up and going back to sleep. If you zoom right in on the two events at 4:10 and 4:40 you might learn something. The flow graph would be the one of interest. In my issues with CA what I often find is a minor OA event that is not long enough to be flagged will start to cause my breathing rate to be unstable, and eventually end up with a CA event. It is worth looking at what led up to the CA event to see what may be the cause. If you post a zoom in of each of those events I can give you my thoughts. They need to be zoomed in to the point where you can see each individual breathe in detail. It is the period of time leading up to the CA event that is most important to look at.

Your pressure increases seem to be in response to flow limitations. Those may be caused by body position. I think I mentioned before that some go as far as sewing a tennis ball into the back of their PJ's to encourage sleeping on one side or the other but not on their back.

In the scheme of things, there is not much you can do with central events, and your incidence is not that high. Limiting pressure can help, but your events do not seem to be caused by pressure. BiPAP machines have some limited ability to deal with central events. However, when central events are a much more serious issue the best machine are the ASV types. In range of cost, an APAP is about $1,000, the BiPAP about $2,000, and an ASV about $5,000. With your current numbers I see no reason that you would need more than an APAP.

Well, you have kind of a Dr Jekyll and Mr Hyde behaviour in your apnea outcomes. With the collar and sleeping on your side it looks like 13 cm is fine, but when you get into the more difficult position it seems that 20 cm is almost not enough. My thoughts are that you should do just fine with a standard APAP if the position is controlled. And the other consideration is that running up to 20+ for pressure is not going to be the most comfortable and the easiest for a mask to deal with. And, higher pressure may drive up your central apnea event frequency.

I guess one thing to consider is that a VAuto BiPAP can be set up to replicate what you are getting for treatment now with the APAP. If you are paying for the machine, I would not consider it, but if they are giving you the machine there is probably not much of a downside. I have not looked at the VAuto for some time, but it might be missing a feature or two compared to the latest AirSense machines. For example I am not sure it has the auto ramp feature, but that is more of a nice to have, than a must have.

It is hard to say if raising EPR above 3 would help much. You certainly do have periods of more flow restriction where it may help. I think overall your results have improved by having EPR at 3 cm, but it is hard to predict if more would be of benefit. If you were to get a VAuto I would suggest that you set it up to replicate what you have now. Then you could experiment to see if more pressure support is of value or not.

I agree. It takes time and patience to get the right settings. I have changed my setup 22+ times, and now think I have it pretty much right. I had a data problem with SleepyHead and the first entry at the bottom is not correct. Within that time period I changed set up a number of times.

A second check for the humidifier is the amount of water it uses. When we use our trailer and run off DC, I turn the heated hose and humidifier off to save power. It uses essentially no water when it is off.

How do you have the humidity and temperature set? I put them both in Auto.

Here is a video showing the seals inside the machine. The part on the right along with the seal is removeable and you can buy it on line for $10 or so. The one on the left if that is the issue, is more difficult. This video is suggesting you clean it, as the dark spots may be mold. Might be worth a try. There are other videos that show how to tear the whole machine down, but if you can't get the replacement seal then that is still a problem...

https://www.youtube.com/watch?v=3O7tzeLDHj4

Your leak rate chart does not suggest you are opening your mouth. Normally those events will be sudden and have a flat top somewhat above the leak redline. If anything, some of these events appear to be related to waking up and could be just sleep wake junk. If you are not comfortable with a mask then the chances of waking up are greater. It is possible you are more comfortable with the F20 and that is the reason it is giving better AHI numbers.

I have had a look for a source of replacement seals on the machine, without any luck. Here is a link to a company that sells second hand as well as new machines. If you called them, they perhaps would be able to suggest where to get parts. I could not find the exact seals on a search there. Your leak rate chart is sure showing there is a fixed leak.

https://www.secondwindcpap.com/

In any case despite the higher readings on this night, I think the machine is getting close to the best you are going to get out of it. You could try going lower in minimum pressure, but that might not bring any improvement. OA events could start sooner, and the pressure would go up anyway.