SleepHead Data Shows Difference Between Nasal/Pillow Masks

Good morning everyone,

I use a combination of masks as the need arises. You know, even our noses have attitude:

ComfortGel Blue Nasal CPAP Mask with Headgear (Pressure 10)
Wisp Nasal CPAP Mask with Headgear (Pressure 10)
AirFit P10 Nasal Pillow CPAP Mask with Headgear (Pressure 9)

Both nasal masks show bad data as one I have provided. However, with the AirFit P10, I have always had a ho-hum attitude until recently I noticed a significant difference in data. NOW I am going to make the AirFit P10 my go to mask. The only reason I changed the pressure with the AirFit P10 is because of the direct flow of air going into may nasal passages and to lessen the likelihood of gas in my gutt.

So, I need some understanding. Why the change in data based upon the type of mask I use? The only thing I can think of with the AirFit P10 is the "direct" airflow does a better job of keeping throat passages open than the nasal masks.

Also, I've notice that when the AHI rises as you can see, I wake up. Why?

So what gives? Looking forward to your responses.
Starlette

PS...When I checked the data this morning using the pillows, it looked just as good.

Are you using a EPR? The reason why I ask is that the EPR may respond differently depending on the Mask, and not give you the support you need with one mask, but work better with another.

Also, if you are, I would turn it off (except for ramp) with the P10, and go back to 10 cmH2O to eliminate your obstructive apnea. Think about it this way:

In constant pressure CPAP, after the first breath (especially with well sealed nasal pillows), the air inside your lungs is always about the same pressure in the hose. The velocity of the air is dictated entirely by the speed of your diaphragm, which will be steady, and well controlled when you are asleep. Whether the pressure is at 10 cmH20 or 9 cmH20, the air velocity going up your nose is still the same. On the other hand , if you use 3cmH20 EPR, you have to make up the difference of air pressure on each breath (your lungs have to go from 6 cmH20 to 9cmH20 or 7 cmH20 to 10cmH20), so the air velocity will be slightly higher.

WindCpap wrote:Are you using a EPR? The reason why I ask is that the EPR may respond differently depending on the Mask, and not give you the support you need with one mask, but work better with another.

Also, if you are, I would turn it off (except for ramp) with the P10, and go back to 10 cmH2O to eliminate your obstructive apnea. Think about it this way:

In constant pressure CPAP, after the first breath (especially with well sealed nasal pillows), the air inside your lungs is always about the same pressure in the hose. The velocity of the air is dictated entirely by the speed of your diaphragm, which will be steady, and well controlled when you are asleep. Whether the pressure is at 10 cmH20 or 9 cmH20, the air velocity going up your nose is still the same. On the other hand , if you use 3cmH20 EPR, you have to make up the difference of air pressure on each breath (your lungs have to go from 6 cmH20 to 9cmH20 or 7 cmH20 to 10cmH20), so the air velocity will be slightly higher.

EPR is a feature of ResMed machines...the OP is using a Resperonics

Well, it sure looks like the P10 works better for you. Could be a number of reasons, leaks perhaps? The way the therapy is delivered perhaps? The big question is do you feel better with the P10? At first, I think, pillows feel like the pressure is greater than other types of masks, but with me that feeling went away fairly quickly. I think if I were you based strictly on the numbers I would stay with the P10 and work to bring the AHI down even further. You might be able to do this by increasing the pressure a little and/or as windcpap suggested turning off Aflex if you are using it.

A rising AHI would tend to mean more disturbances, arousals, and awakenings.

LSAT wrote: EPR is a feature of ResMed machines...the OP is using a Resperonics

In that case C-Flex.

ResMed users who are new and think that the Flex relief on Respironics is just the same as EPR is on their ResMed machines....it's similar but not exactly the same.

First thing...the maximum reduction during exhale with Flex relief is 2 cm...even at the setting of 3...it's not a per cm reduction like EPR is.
Flex relief is exhale relief in the form of a reduction in pressure during exhale but it auto adjusts the amount of actual reduction based on the air flow or it's what we called "flow based reduction". If someone is a forceful breather then they are likely to get the maximum of 2 cm at the setting of 3. If someone is a more shallow breather they may not attain that 2 cm reduction at a setting of 3. We have no way to know exactly how much reduction there is...just that the most we can get is 2 cm at the setting of 3.

Secondly due to the smaller reduction and the way it is delivered the chance of Flex impacting the AHI itself is smaller...meaning turning Flex off (either C Flex in cpap mode or A Flex in apap mode) may or may not improve a slightly higher AHI or the results might not be as apparent as is sometimes seen with ResMed machines.

As to original question as to why a lower AHI with the nasal pillows when compared to a nasal cushion.
I dunno....it can happen when comparing to full face masks for sure as that is often documented but I haven't seen it documented much (one other time by a nasal cushion user who noticed an improvement with nasal pillows) so I suppose it is possible.
I don't know that we know exactly why and I have come to accept that sometimes we don't always have clear cut answers to some of these questions.
All I know is that we could/should use whatever works for us and lets us sleep the best and feel the best and if using a nasal pillow mask let's us use a little less pressure and get the job done...it is what it is.

Perhaps it's even a combination of factors...including sleeping position or something.

I actually looked up the difference. My point was that the machine response to EPR/C-Flex is going to be affected by the volume of the mask, and it is possible that the difference in response is causing the difference in AHI. If using a constant pressure, any differences wouldn't be so pronounced. This thought was drawn from the fact that most titrations are done using a nasal mask (not pillows), and the first place I would personally look to troubleshoot a difference in AHI is in the variation from the prescription concluded at the sleep lab. EPR/C-Flex is one of the first things that people change on their prescription.

Windcpap,

Would you be so kind to rephrase what you just said in layman's terms level? *Flew past my head*

Starleatte

Starlette wrote:Windcpap,

Would you be so kind to rephrase what you just said in layman's terms level? *Flew past my head*

Starleatte

Apologies. Mechanical Engineer.

Point 1:

If you are using constant pressure (No C-Flex during sleep) one would expect the results from the sleep lab to correlate well regardless of the mask you use.

If you are using C-Flex, the volume of the mask, and how directly it interfaces with your body would effect how the machine sees and interprets your inhalation/exhalation pattern, and therefore effect how the C-Flex pressure variation is delivered. I would expect that a direct interface (through nasal pillows for
example) would allow the machine to better interpret what is going on, and respond more appropriately, thus resulting in a better therapy.

Point 2:

The therapy pressure is not relevant to how fast the air goes through your nose during normal breathing. If the pressure is set to 10cmH20, you will have 10cmH20 pressure in your lungs after you inhale. While you feel this as an increased effort in exhaling, the speed of the air rushing through your nostrils is the same as if you had no CPAP on at all, and were just breathing through your nose. Of course, if you open your mouth and let the air leak out, the speed of the air traveling through your nose and out your mouth will be increased with increasing pressure.

On the other hand, if you are using C-Flex, you will have a spike in air speed on each breath as the pressure increases during inhalation.

As an added side effect, the higher your pressure, the more your nostrils will be splinted open (works the same way CPAP works on the rest of your airway), so you will breath easier when a little stuffed up at 10 cmH20 vs 9 cmH20