EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA

[AshSF]

I have woken up hyperventilating a bunch of times on the p10 (mostly in the coldest part of the winter). I always brushed it off as some rainout clogging the p10 frame under the nose. And it would be hard to get back on to the regular breathing of the mask. The rhythm goes away and you can't easily get back on the running horse of inhale:exhale.

I went a bit deeper this time and saw the leak rates. I have a dreamstation auto that shows the total leak rate. And the p10 was venting a total of ~10Lpm on the nights I woke up hyperventilating. On my constant pressure of 8cm h2o, it should vent more than 25Lpm (according to its brochure).

The frame is more than a year old. It's washed every 2 weeks with dish soap and a brush. But over time, it seemed that you could never clean it completely.

My solution has been to punch 2 holes on each side of the mask. Now it wents at 25Lpm when freshly cleaned, and 20Lpm when dirty after 2 weeks of use.

Reading this whole thread, it seems to me that total 10Lpm of leak rate or lower, is where the body starts feeling the staleness of the breathing air. So If you are a P10 user, just keep this in mind. And maybe experiment with punching holes in the frame (just to be sure).

Kudos to the OP doc who did all the research.

[Rbtl]

I have followed and benefited from this board for a while, finally registered to post.

The original post goes back to 2019, but I see now as I reply it is still a concern, so here is my experience.

I love my P10, not sure I would have stuck with therapy if I had to use a bulkier mask.   I used the first four masks for 4-5 months each, even though they are replaced every 3 months by my insurer.    I do not use a humidifier or heated hose.   I don't know if anyone actually scrubs the whole apparatus daily, per the manual- I never have, but I do wash and brush the vent at least weekly or so, the pillows every few days.  Never had a problem with the first 4 masks.

Back in January, I had difficulty breathing within minutes of putting on the mask and trying to sleep.  Plenty of flow, but felt like I wasn't getting oxygen.  I cleaned it up the next day, it was fine for a few days, and then happened again.  This one (#5 of mine) was only in service about 2 months.   Similarly, #6 was ok for about 2 months, then the same thing.  I am back on an older P10 that has maybe 4-5 months on it.

After the first problem, I built a mini orifice flowmeter (yes, retired engineer, but not nearly as thorough as the original poster with real time CO2 measurements- what a great post!).  With the pillows plugged (foam ear plugs work great for this), using the mask fit test option on my Airsense, the flow of a new or properly functioning P10 is about 90% of specification (there is a curve in the manual for liter/min vs. pressure- the mask fit always runs at the max pressure of the device, in my case 10 cm, with a spec flow of 32 l/m).   90% is very close for my improvised flow meter.   The masks that have caused me trouble run 60-70% of spec vent flow.  Brushing in soapy water restores some flow, but never so far back to the 90% range.   I think the reduction in vent flow is sufficient to cause problems with rebreathed CO2.

What I don't know is if the premature failure is due to something new in my environment (dust, my own runny nose, etc) or not cleaning enough to prevent accumulation that can't be removed.  I may try some of the remedies mentioned in other posts (different cleaners, forced water or air pressure, or poking a few needle holes in the vent area).   Or, is there a manufacturing variability that causes some P10's to clog much faster than others?  I am lucky to have coverage for 3-month replacement, and I could afford to purchase a spare each cycle if needed, but beside the cost I hate throwing out plastic and $100 items before I have to.   The mask really works for me both in comfort and in not blowing a hard air stream across the bed, so I'll probably stick with it.  I considered inquiring with the manufacturer, but posts going back to the original indicate that hasn't gone anywhere.

[allama]

Thank you for this article and research! It may have saved me from giving up completely on cpap.

I had such a bad experience my first attempt at cpap because of a mask that didn’t work for me. I took almost a whole year to retry CPAP again.

I had high hopes for the p10. I just started using it this week and immediately it got rainout and clogged completely. Brand new mask too. Luckily I keep some compressed can air handy for computer stuff, and was able to blast the moisture out of the mask and go back to sleep, but I was disheartened to say the least when it got rainout and clogged 3 more nights in a row. Then I found this post!

I have since made adjustments to prevent the rainout. I even have a water-pic ready for when it’s cleaning time. I have a barrel cosy and hose cover for the short hose section and it helps a lot.

I still get a lot of upper lip sweat, but no more clogging of the vent so far. I’m even going to check out some other nasal masks recommended in the replies, but it is really nice having a working p10 as a backup. Thanks to this thread, I am armed with the knowledge I needed on how to fix the issues I was having.

Thank you, specifically to the OP, but also to all those who made replies that gave insight and info!