+- Apnea Board Forum - CPAP | Sleep Apnea (https://www.apneaboard.com/forums)
+-- Forum: Public Area (https://www.apneaboard.com/forums/Forum-Public-Area)
+--- Forum: Main Apnea Board Forum (https://www.apneaboard.com/forums/Forum-Main-Apnea-Board-Forum)
+--- Thread: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA (/Thread-EVIDENCE-OF-AIRFIT-P10-VENT-OBSTRUCTION-CAUSING-HYPERCAPNIA)
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - Snoring Bear - 05-29-2019
(05-29-2019, 04:57 AM)spirilis Wrote: Man this thread scared me as I have noticed lately awakening more groggy than my 1st week of therapy (in week 5 right now) and I've cleaned the mask a couple times.
For good measure I soaked the mask in hot water for a few minutes and blew it out with compressed air (seemed to flow OK). But then I figured out how to reach the clinician menu on the Airsense 10 and found EPR set to Full-Time, 2cmH2O, and switched it to Ramp-Only. Woke up this morning a bit sharper than usual.
I'm glad last night's sleep was much better for you!!!
I believe the instructions for some reason say to use warm water...? I use warmish to hot water and soak my vent piece and pillows component for about 10 minutes or more in the water with "mild soap". Then I use a soft bristle toothbrush to clean both sides of each vent. Finally I rinse each part well in warm water and shoot a jet stream of water through the vent holes on both sides. That seems to keep the head piece/with vents looking just like new. Although the instructions say to clean them "every day", I normally clean them about every other day or so.
I've read that one thing that can happen with masks in general, if they're not cleaned regularly, is that the oils from your skin can rub-off on the mask and cause leaks from improper sealing...I assume that is correct. - - However the main reason I'm somewhat diligent about cleaning my P10 is due to this thread which I read months ago. Knowing that the vents "can get clogged", I've placed a priority on cleaning my mask regularly.
Btw, my understanding is that having EPR turned on will make it "easier" to exhale air, and of course "ramp" will gradually get you to your desired pressures. I turned both my ramp and EPR off a long time ago as I didn't particularly need the ramp and EPR and preferred getting "full treatment" right away. I realize everyone is different and needs to adjust to one's own comfort level.
Good luck on your continue progress spirilis...you're doing much better than most at this early stage in your cpap usage!!!
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - Apnea Infant - 05-29-2019
Thank you very much for your reply, mdmarmd.
I did your moistened back of hand to test the the vents were open immediately. Thanks for clarifying oximetry cannot confirm rebreathing CO2.
I have to clean the mask more regularly than I have.
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - kingskid - 05-29-2019
Hi Doug. You’ve given all of us P10 users a lot to think about. I hooked up what I think was a new pillow holder and new pillow in my Airsense, turned it on and tried the test of water on the back of the hand. Couldn’t feel any air coming out. My AHI is usually under 1, but have a lot of RERA and CA readings. I really have not been able to interpret my charts and need to research what they are telling me. If the AHI is all I need to be concerned about, then I can relax. I frequently remove my mask after 2 hours for some reason. If I can make it 4 hours, that is really good. I don’t have some of the symptoms mentioned, but since I started CPAP 4 years ago because I stop breathing sometimes during the night, I think I will try my DreamWear nasal pillow mask once again. Thanks for all the info you gave us.
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - spirilis - 05-29-2019
Fwiw, with my 5 week old P10, I can definitely feel airflow on my hand (cool when inhaling or holding my breath and warm when exhaling) during a Run Mask Leak test, no need to wet my hand...
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - kingskid - 05-29-2019
I only tried exhaling, but will try inhaling, too.
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - trailrider - 05-29-2019
My personal anecdata is no issue with P10 since 2015. I'm a bad owner. I use it every night, never clean. Don't bother with humidity. Change filters less often than I should (but I've always used the hypoallergenic ones). I'm on my second mask since the first one was sampled by the puppy 2 years ago. (It was the noise through the resulting indentations that made me buy a new one)
The situation OP finds may be a combination of humidity with dust, making a coating under certain conditions.
Great set of testing and analysis!
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - mdmarmd - 06-01-2019
TACIT ASSUMPTION THAT THE AIRFIT P10 PASSED RIGOROUS CLINICAL TESTING TO GAIN FDA APPROVAL
For context, I am adding some snippets from the two long threads regarding P10 obstruction (skip if not interested):
AshSF: Moisture is not retained in the P10 mesh…Even if some water is lodged in there, it will be easily pushed/evaporated by incoming air from the machine. If that were not the case, and the water was indeed blocking the vent, it would be a major design flaw (since Resmed has to account for rainout conditions). It would also expose Resmed to lawsuits of angry, dazed & zombie PAPers complaining of CO2 rebreathing.
OpalRose: Also have to wonder if there were a real problem with this mask, wouldn't ResMed have pulled it by now? It is one of the most popular masks out there.
TyroneShoes: I honestly don't think the vent is blocked, and I honestly don't think anything can actually get on the vent and solidify and block it.
…I think it is just designed really cleverly, to not put out a concentrated stream of air, but to disperse it. They have to have designed it to exhaust CO2 properly, or they would be liable for a class-action lawsuit. There is no chance that they designed a medical device so nonchalantly that it would work that improperly and risk CO2 rebreathing.
…But it would be ludicrous for it to be designed without proper venting, or to be designed so that something could get in the holes and block the air.
…Physics works, and this is a good example of talented designers who know what they are doing addressing the annoying air stream issue of previous designs. They did it so well that it is hard to even realize that the venting is working. The did it so well that we now have a 12-page conspiracy theory thread about it. I consider that a testament to how well it was designed.
PaytonA: …Lets not deify the Resmed designers quite yet.
Sleeprider: …I think a lot of you are trying to fix what is not broken. Yes, the diffuser has a fair amount of resistance on exhale when you block the tube, but that is not how you sleep. It passes plenty of air with the machine on to purge the hose and avoid rebreathing, and exhale pressure is never more than what you have your machine setup to deliver.
… A cold room will make condensation at the vent more likely. I don't consider any of this a defect in design, but more awareness of avoiding moisture on the vent is probably a good idea.
AshSF: This thread refused to get settled one way or the other. I was initially in the first camp which asserts that the vents are blocked. But after some research and experiments, I have moved to the other camp which assert that there is nothing wrong with the mask.
Seems that most people who suspect something wrong with the P10 are running Resmed machines. Since Resmed doesn't show 'Intentional leak rate', it's hard to convince them that the mask is venting properly.
alby_c: I know how the mask performed when I first got it, and for some months after - it was great. The diffuser worked well, I could breathe, I could just feel the exhaust, but I could feel it.
Then it blocked. I could not breath out. I finally understood people who said they felt a mask was smothering them as I had not experienced that before. I could feel nothing from the vents etc. It blocked up. It was not like this to begin with. It is substantially altered in its performance.
Saying I am dreaming an issue is not helpful, nor accurate. I really liked this mask and want to figure out how to get it working again without doing it violence.
palerider: the p10 and the swift fx and swift lt, (I couldn't find an lx) all vent at exactly the same rate when new (check the charts in the back of the manuals.)
BadGoodDeb: My lungs disagree with their vent chart.
palerider: your (probably) imprecise interpretation of the measurements from your wet, squidgy, floppy, gloopy meatbags not agreeing with scientific measurements isn't really much of a surprise
euquiq: The only mask that I learnt to hate is the P10. I sincerely think that Resmed guys did not think as hard as they should have on this mesh design.
herbm: Also note that the odds of your being able to "improve" one of these very carefully designed masks with pin holes are very, very close to NIL.
…High humidity and/or a cold room can easily cause condensation in the hose -- the water is condensing and collecting in the HOSE, not in the mask (to a virtual certainty.)… The film I am hypothesizing is something cohesive enough it doesn't wash off trivially so it would be more than JUST moisture.
chris61: Today I called the Dutch supplier and the representative admitted that the blocked vents was a more common heard complaint of the P10....
Cuppa: I suspect it will only be a matter of time before Resmed sees fit to change the design, (to what otherwise is a great mask)
HULK: So, with a diffuser such as this, the air volume and pressure become critical factors. Due to the shape and design of the vent holes, as the volume and pressure increase the back-pressure increases at a greater rate. This occurs due to turbulence as the air is forced through the vent holes faster than they want to allow.
...This is easily tested by blocking the hose and breathing out slowly a lung-full of air. It is reasonably easy. Do the same and breath out quickly. There is a lot of resistance.
...Block the exhaust vents on the mask (just put fingers over them) on the exhale and compare the back pressure to when using the mask with the vents uncovered. If it is about the same or less, the back pressure in the supply tube is less than the back pressure from the vents so some (or all?) of your exhaled breath will be going down the supply tube, i.e. re-breathing.
...Whatever the result of the debate above it is a simple fact, in a system where there is no non-return valve, to avoid expiration going back down the tube and being re-breathed, the pressure provided by the CPAP machine must be always higher than the back pressure from the mask vent.
...So, getting the pressure balance correct is problematic?
The dangers of Hypercapnia (Carbon Dioxide Poisoning) are well known and researched...
...Consequently, I assume that RESMED has put considerable time and research into preventing this happening?
...While I applaud RESMED for engineering such fine equipment… I am concerned about the absence of information they are providing to Consumers, Physicians and Technicians...
...Should there be monitoring and measuring in place to ensure re-breathing is not occurring?
...If it is the EPR allowing the pressure in the supply tube to drop below the back pressure of the mask vents, should there be a warning about using it with masks that have no non-return valve in the supply line?
ajack: G'day, I understand your concern and it looks like you read/misunderstood some scarey stuff, but we as a group here have thousand of man years under the belt. cpap increases o2, decreases co2. There is no rebreathing risk because of the venting when enough volume is being moved.
HULK: In chewing through all this data i cannot reconcile the basic observation "I noted that there was venting out of the P10 Most when breathing in but either very little or none, when breathing out!"
TBMx: if you would suffer Hypercapnia you would start to hyperventilate ... your respiratory rate hovers around 13 - which is like 10 miles away from that…nd be assured: there is no such thing as negative flow back in the machine. You might be "strong" enough while awake (or at least believe that you can breath forcefully enough to do that - but I doubt anyone is stronger than the turbines in the machines) but not during sleep - you would simply open your mouth to exhale. (and you would do the very same thing before starting to hyperventilate through your nose - except you did some crazy stuff to not be able to open your mouth)
DaveResmedP10: HULK I found exactly the same issue with my new P10 and I believe you are totally correct about rebreathing CO2 concerns.
It took a few nights to figure out what was going on. By the last night of use I was a mess, woke up several times breathing fast and heavy like I was running up hill. Mouth breathed for a while, things normalised and I would go back to sleep. Felt progressively more drugged during the day and my head was swimmy. Changed back to my old FX mask and things are improving.
I really like the comfort aspect of the mask so have been trying to figure out whats going on, searching online etc and your CO2 info really struck a chord. Oddly, yours is only the second post I have found anywhere online where someone talks about concerns that the P10 is not venting enough.
I have contacted the retailer and Resmed about it mostly to ask if it could be a manufacturing fault because the vast majority of comment online is all good. Resmed say 'no such probelm exists, never had a manufacturing fault, you need to get used to it or change masks'.
bonjour: I disagree with modifying any part of the air delivery system, including the mask. The mask is engineered to deliver air and vent a certain amount of air to prevent CO2 rebreathing
PaytonA: What would be the problem with more air venting than the "engineered" rate. The only danger that I see is getting to too much venting for the machine to handle when inhalation is added to it.
PaytonA: First, putting holes or slits in the vent diffuser may sound like a baaaad thing since someone probably spent a fair amount of time engineering those vent diffusers. The fact of the matter is that increasing the vent rate should have no negative effect on anyone's treatment efficacy with a Resmed machine unless you increase the venting so much that the machine can not keep up.
bonjour: Air in the system is designed to be balanced at some point and it must be balanced from 3cm H2O to 25cm H2O, the full range of pressures used for cpap treatment. This includes air delivered to the mouth/nose and the air vented. You can over vent which could result in the inability to deliver adequate air to the mouth/nose. Also you could under vent resulting in too much CO2 rebreathing…Without a solid method of knowing how to measure this balance I cannot recommend encouraging anyone to make alterations.
PaytonA: What do you mean "balanced'? This is an open ended dynamic system and as long as you have at least enough venting then the person is safe. Since one would be increasing the venting from what is "engineered" to be safe, one would still be safe. It would be difficult to vent so much air that the machine could not keep up by just modifying the P10 diffuser with pin pricks or small cuts and one would feel it if the machine could not keep up. We have a number of people that use this kind of modification and they are still on the forum…I do not promote modifying the vents but I think that too much emphasis has been placed on the "danger" of modifying the F10 vents.
PsychoMike: HeyHulk, I'm another with extensive SCUBA, SCBA, AvOx and RPE experience. I find that the CPAP machines are most akin to a PAPR set-up. The PAPRs don't need the oral-nasal cup in them due to the constant flow of air (just like a CPAP). The increased dead air space and normal exhalation should not result in excessive build-up of CO2, assuming the diffusive vents are working properly.
You are correct that you can breathe out and feel the results of the excess backpressure (the vents can only clear so much in a fixed amount of time), but don't forget that they are constantly venting and the machine is constantly pushing air through them...it would take extraordinary circumstances for it to lead to a hypercapnia event (i.e. blocked vents). HULK: The scary thing was when waking, noting the pressure was low and feeling as though I had been re-breathing. I would cover the exhaust vents by putting my fingers over the vents when breathing out. There was no difference in breathing back pressure with them covered or un-covered! So it was quite clear, that the path of least resistance was back down the tube. Re above, some theory to consider and questions for those who know a lot more about this stuff than I: When sleeping, what is the pressure of exhaust breath? The pressure back down the delivery tube is Exhaust breath pressure - Mask Vent back pressure. Is this pressure back down the supply tube sensed by the S9 so, it will wind itself back to meet the minimum pressure? Hence, making it quite easy to blow back against the CPAP pump?
PaytonA: The nasal and nasal pillow masks do have their own anti-asphyxiation valve. It is called.......your mouth. Sorry I could not resist. The logic is that if your machine quits operating while you are asleep you will open your mouth to prevent asphyxiation. Since the fullface mask seals off both the mouth and nose it was felt that they needed their own method for preventing inadvertant asphyxiation.
HULK: I agree with PaytonA, there is an anti-asphyxia valve - i.e. your mouth.
So, as a nose breather, perhaps this is why I had incidents of opening my mouth?...Don't we all have a natural mechanism that when there is no or poor quality air through the nose, we instinctively/subconsciously go the back-up i.e. mouth?...As the appliance used to manage the mouth opening was a chin strap (just one of the number of commercially available ones specifically for this purpose), did this make the issue worse be limiting the ability to open my mouth? Of note, it was suggested that strips off tape could be placed across my lips! I believe this could be highly dangerous as the anti-asphyxia valve is your mouth.
PsychoMike: Yes, there is more dead air space volume so you do re-breathes some additional volume of exhaled air when using CPAP. However, unlike a snorkel, the effective dead air space volume is far lower than the amount of volume in the tubing due to the constant air flow from the blower of the CPAP unit itself. In other words, it's not like you're breathing through a 6' hose and, hence, re-breathing 6' of exhaled air....but yes, there will be some minor additional re-breathing of exhaled air for ALL CPAP masks. Again, the effective increase in re-breathing volume would be quite minor (probably less than that of a snorkel, TBH). I'm not sure why you were having an issue with the pillows mask (unless there was an issue with the exhaust ports)…
HULK: TBXx's comment.... "but I doubt anyone is stronger than the turbines in the machines" intrigued me?...I would have thought this to be the case?...To be sure, I thought I would test it by blocking my nose and mouth breathing directly onto the delivery tube. Pressure 6, no EPR…I was surprised at how easy it was!
DaveResmedP10: In the case of the P10 nasal pillows mask and CO2 poisoning we have to consider several factors particular to the P10. It has a mesh vent with hundreds of tiny micro sized holes. This is a big departure from other vents I have seen that have a lot less and larger holes. The frictional forces are proportional to the surface area the air has to pass over. Logic dictates then that the P10 has greater frictional value than other vent types with fewer but larger holes. My observations/tests have proven with normal light breathing the P10 can vent sufficient exhaust air. However, although the mask is continuously venting, its not enough in all circumstances. Even the manual states ‘some rebreathing may occur’. What is the value of 'some', at what point, for how long and how often!!?? If you get into a state where you start to breathe heavier it does not vent all exhausted air. Additionally the micro sized holes are easily restricted or blocked by moisture. Whether you haven’t dried it properly, have condensation in your tubes, cough, sneeze or just blow out hard you can block up the tiny holes with moisture. The effect lasts a long time. Its surprisingly hard to clear moisture from this vent design.
…Where exhaust air is rebreathed a feedback loop can ensue.
If you are breathing air with higher CO2 levels than 400 ppm your body automatically makes you breathe faster and deeper to compensate. The exhale pressure inside the mask will increase as you blow out more volume faster. The vent flow rate is not proportional so the amount you blow back down the tube increases and so the proportion of air at 50,000 ppm you rebreathe increases. This new level of CO2 is additional to the amount your body produces and therefore the level of CO2 on your next exhale is higher again, stepping up with every cycle.
The effort required to breathe harder increases your bodies CO2 output therefore up goes the level of CO2 you are exhausting and so rebreathing… away it goes again and a negative feedback loop ensues.
Some comments have been made that you have safety features called your mouth and waking up. With low level CO2 poisoning neither of these may apply, especially when one of the symptoms of CO2 poisoning is sleepiness. As a nose breather mouth breathing is not automatic for me…I think we should be demanding more information from the manufacturers. Vent rates at given pressures and clear warnings as to the risks of CO2 where when and how - if only for the small percentage of users that are at risk.
SnoringInOregon: That 23 liters of air is going somewhere…It could be leaking before it gets to my pillows. In the dreamstation itself or in the hoses to the P10 mask. Or in the P10 mask ahead of the pillows and vents. I haven't detected such a leak…It could be leaking right at my nostrils. I don't think so. I'd notice something like that…I could be exhaling it through my mouth. No, I'd notice that too. I have no problems keeping my mouth closed while sleeping…There's only one place left for those 23 liters per minute. They're flowing out of the vents in the 10 mask. Where else could the air be going?...claim (and this is the only possibly dubious statement here) that this rate of air flow is more than sufficient to rapidly clear any and all of my exhaled CO2.
DaveResmedP10: As a separate issue regarding the technology, how much can we rely on the data. How precise is the reporting. We are relying on it to making some pretty important decisions. Do the units have a flow sensor or just making calculations based on current draw of the motor. It’s one thing to use data to inform choices and improve sleep experience its totally another to use the data as precise risk assessment.
The point of restating these posts is to underscore the fact that most of us assumed that there must have been precise engineering and a scientifically rigorous process that led to the certification of the AirFit P10 and it’s release to the market. We also assume that a medical device that could seriously jeopardize one’s health would be subject to heightened scrutiny.
(In my view, many of these comments in some way appealed to this basic assumption. I believe other comments reflected “pseudo science” where extrapolations made from givens were extended to unknowns. One of the most obvious was the use of published bench tests results on flow rates to disprove concern that vents could obstruct, that back flow could occur or that CO2 could rise significantly. In essence you are using a circular argument that high flow proves that vents can’t obstruct, when high flow is predicated on non-obstructed vents. An analogy that comes to mind is arguing that a stream carrying pollution into a river had inconsequential risks because the high volume of water and rapid flow in the river would effectively dilute and flush out the pollutants. That might be right…unless you dam the river: Then the flow rates of the river no longer apply since the river has effectively been converted to a lake. Now, concentration of contaminants from the stream will not only rise in the river, but also begin to flow upstream.)
FDA APPROVAL…OR NOT
I gained some additional insights in
In my conversation with the Harvard professor of sleep medicine that I mentioned earlier he did a “back of the napkin” calculation regarding the effect of high inspired CO2 on alveolar O2:
Dr: I just did a little calculation depending on how high the person's PCO2 gets, during the time that they are breathing at 40,000 parts per million or 45,000 parts per million, you're inspired O2 at that time is probably like in the fifties could be in the 50s or anywhere between 50 and 60 or a little lower depending on how...so the longer it, the longer the PO2 in your blood is going to be falling, um, as the CO2 rises, and your blood rises. But at the same time, um, the inspired O2 is, is getting lower as well because the CO2 is rising so the PO2, could be in the, in the 50s or lower depending on how long the person is breathing with the elevated CO2, which is not good for you…
510(k) CLEARANCE:
Another interesting bit of information conveyed by this Harvard sleep doctor was that ResMed is not actually required to submit completely new clinical testing data to support approval for the release of a new CPAP mask on the US market. They only have to submit, what is called a 510(k) Clearance:
Dr: You don't have to get your mask approved by the FDA.
Me: Oh, I didn’t know that.
Dr: Not really. They don't have to do any special testing on that in order to submit to the FDA. I
mean it's like if you have new brand of Kleenex, you don't get it approved by, I mean, they
might have to fill out a little bit of paperwork, but they don't have to, they just have to certify is
just like any other mask
Me: But you do have to get a prescription for it?
Dr: Oh yeah. But that doesn't mean anything.
Me: Now that's rather cynical view of the FDA.
Dr: I mean there are more, there are like 10 or more CPAP manufacturers. I mean they, they have
to get there a device approved,
but the, the approval processes, they don't have to submit any new data on their device. They
just have to certify that it is basically essentially equivalent to what else is out there on the
market and performs identically. So they don't have to do any real fancy testing on this.
Me: That's interesting.
Dr: It's called, that type of approval is called a 510(k). And so it basically, it just basically means the
first person had to get some sort of proof. But after that, people who kind of manufacturer me
too-type stuff for this sort of thing, they yeh, it's like these masks or, the hoses or any of that,
the amount of testing is pretty minimal. And for these masks, I'm sure they didn't have to do
any testing. I mean they probably did some testing for their own good, to make sure that it
worked, but they didn't, they don't have to like submit stuff to the FDA. They probably just had
to submit some forms saying that hey, we're putting on a new type of math. It's kind of like our
last version and FDA will say. Okay.
Me: What's kind of weird though that if you make a product that specifically states in the user
manual, if, the vent is obstructed, you can suffocate. that sounds like a...
Dr: But that wordings in there for all these masks. I mean if you obstruct the valve on the other
masks, that will have the same effect.
Me: Right. I know, I know that. But it seems like you as a company would want to take some
measures to make sure that it doesn't obstruct by design. Not by accident. I mean it's one thing
if someone tapes over the vent, it's another thing if you're design actually increases risk of that
happening.
Dr: Well they probably didn't think much of it. You know, Boeing didn't think much of the software
change on the seven 737 Max either so.
“510(k)” is actually a section of the Federal Food, Drug and Cosmetic Act (FD&CA, the Act) from which this process was derived. The process is somewhat analogous to the “generic” drug concept in that Premarket Notification is used to obtain marketing clearance for a device that is “substantially equivalent” in safety and effectiveness to another lawfully marketed device or to a standard recognized by the FDA when used for the same intended purpose(s). Note that the concept allows for technological advancement; the new device does not HAVE to be manufactured from the same materials or perform its intended purpose using the same technology. The new device must exhibit roughly the same safety and effectiveness characteristics as the “predicate” device to which the new one is being compared.
A successful 510(k) submission results in FDA permission to market the new device. The nature of this comparison depends on the device and the degree of risk associated with its use. The comparison may comprise physical or performance characteristics as measured by standardized methods.
Some Premarket Notification submissions are based upon bench testing of the new device and a comparison of the findings with the known performance characteristics of the predicate device.
Because of the nature of the laws underlying this process, a successful submission is deemed to be “cleared.” Clearance of a Premarket Notification submission by CDRH (Center for Devices and Radiological Health) confers permission to market the new device. By legal definition, it is NOT an “approval” process.
(https://www.devicewatch.org/reg/510k.shtml)
AIRFIT P10 510(k) CLEARANCE:
I was able to obtain a copy of the 510(k) premarket notification for the AirFit p10 (Swift Air):
[attachment=12415]
[attachment=12416]
[attachment=12417]
This indicates that the predicants used for the Airfit P10 are the Mirage FX, the Swift FX and the Ultra Mirage ll.
Interestingly, the initial design offered two vent option, a traditional multi-hole vent and a new diffused type vent to provide a continuous air leak to flush out and minimize the amount of CO2 re-breathed by the patients. Like the predicate mask, the incorportation of these exhaust vents does not interfere witht he intended performance of the new device.
Makes you wonder if they first considered a Brevida like system with a multi-hole vent, and a snap on diffuser, but settled on a fixed difusser design.
[attachment=12420]
Looking at these, it makes me wonder if the flow dynamics of these are really that so similar that the AirFit P10 would not require actual clinical testing to demonstrate adequate venting, especially under rain out conditions. All the others have traditional porting that would not obstruct with water or, if they did, could easily be blown open.
[attachment=12421]
When comparing close up pictures of the simple pore type vents vs. the extremely tight, fine mesh design of the P10, it is hard for me to believe that an engineer who understands the physics of flow dynamics would think these are equivalent regarding air flow and risk of obstruction, especially if wet.
Were they tested under prominent rain out conditions?
Importantly, it is a legal requirement that ResMed forward any reports of adverse events to the FDA. It seems that those who have contacted ResMed about these concerns have just had those concerns dismissed. In the future, if anyone does contact ResMed, I would advise them to do it it in writing so there is a paper trail. Page 5 of the 510(k) clearance states:
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations adminstered by other Federal agencies. You must comly with all the Act's requirements, including, but not limited to: registration and listing (21CFR Part 807); lebeling (21 CFR Part 801); medical device reporting (reportin of medical device-related adverse events) (21 CFR 803)
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - Snoring Bear - 06-01-2019
My experience, although 4 years less than Trailrider's (2 posts above), is the same as his/hers. Thankfully no problems at all with the Airfit P10!
Yes, I do clean it 2 or 3 times a week to ensure my vents stay open. Last night I came in with a .3 ahi, so I'm very pleased with my cpap treatment... Resmed 10 Airsense Autoset + Airfit P10; I formally used the Eson2 Nasal Mask, but the P10 is much easier to use with virtually no leaks.
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - ghce - 06-02-2019
I just bypassed the problem and have been using the Brevida mask the last 2 months, what a great upgrade to the P10.
RE: EVIDENCE OF AIRFIT P10 VENT OBSTRUCTION CAUSING HYPERCAPNIA - mdmarmd - 06-02-2019
Sorry the text in my post is so enlarged. I must have changed the page size when I was cut and pasting some pictures and left the page size reduced. So I enlarged the font size to make it readable, and of course that made everthing too large. I just realized this when I was viewing the post on another computer.
I was wondering why the text seemed so small.
If you use the Ctrl and minus keys to reduce the page size to 80% or less you can make the text readable.