I had a rather unusual experience with my ResMed AirSense 10 machine and ResMed AirFit P10 nasal mask recently. I thought I would post it in case someone else encounters something like this (or wants to avoid it happening). On Thursday last week I had a quite normal sleep. CA events were a little high, but other than that, normal. Here is the OSCAR daily report. Notice the leakage graph in particular which shows peaks of leakage but none going over the red line. Also look at the Minute ventilation. It starts out elevated at about 15 but quickly settles down. This is all normal for me.
The next night I had trouble getting to sleep and couldn't seem to "get my breath". I did get to sleep fairly quickly though. But there were some unusual graphs. The Leak Rate basically went to zero. I have never seen that before. And Minute Ventilation started out high at 24, but settled down. See this report.
The two nights after that were just as bad or worse. Minute ventilation when going to sleep was as high as 30. I was really struggling to get my breath. The Leak Rate was still reporting essentially zero. And, I noticed that my humidifier water consumption had gone down to about 25% of what it normally is. I presume when there is less leakage there is less water consumption. I increased my Ramp Start pressure from my normal 9 cm, to 11 cm, but that did not help. I was attributing it to the hot weather, but I finally concluded something was wrong with my mask. So I gave it a thorough cleaning. The very fine screen vents on the P10 actually looked black. I have never seen that before. I used vinegar and Dawn soap which is my normal method of cleaning, but the vents did not seem to clean up. I finally used a toothbrush dipping it in isopropyl alcohol, and blowing it from the outside to inside direction with a small portable air compressor. That seemed to work. Here is my results from last night after the cleaning.
Success! Minute Ventilation has returned to normal and the leak rate has returned to normal. And I had a comfortable sleep with no gasping for air. CA events were a bit high, but that happen for me from time to time.
So what caused it all? I guess I could say that we have been having lots of forest fire smoke recently and blame it on climate change. But, I don't really think so. When I think back, I had an oops event on the Thursday before this all started. Instead of turning on the prewarm before going to bed, I accidentally turned on the Mast Fit Test. I recall there was a big rush of air as I did not have the mask on. I kind of think what happened was that the rush of air blew accumulated dust/dirt within the machine into the mask vents. The CPAP inlet filter which is a very fine after market type was clean, so I have to think the dirt came from within the machine and was dislodged by the high flow rate of the mask test. I have been using fine inlet filters for about a year now, but before that I was using quite coarse ResMed filters. I suspect over time they were allowing dust/dirt to accumulate within the machine. I have now done the mask test a few times with the mask and hose removed in hope it would blow out any more dirt inside the machine. It will blow for a short time and then shut down reporting the mask leakage is too high.
I guess we will see if this fix cures the problem. It has worked for one night! Lessons learned?
