RE: Impact of Mask Leaks on AHI?
It might of been you waking up but I think your missing the point about the flow waveform and leaks. Think in terms of sound. If there is no other noise you can hear a whisper across the room. Now blast a radio and you can't hear the whisper all you hear is the radio. It's the same thing with flow. If the leak is too large(radio) it doesn't detect the disturbance(whisper) due to the strong flow caused by the leak.
RE: Impact of Mask Leaks on AHI?
Neither night is showing significant leaks, though they look like they may be mouth breathing, not a concern unless they are disturbing your sleep.
Night 2 your closeup is near the end of your sleep period and could be SWJ (that is Sleep Wake Junk).
Keep in mind that when you are using EPR, it is the EPAP/Exhale pressure, the lower of the 2 pressures that is supporting your obstructive apnea.
As you have noted you have a mix of roughly equal proportions of Central apnea and Obstructive Apnea. I don't thing your CA is high enough that a Dr would consider treating based on the numbers. It can be done but it would likely be based on how you feel rather than the numbers.
The rule of thumb is to increase pressure to treat OA events and to lower it to treat CA events, at least on CPAP devices. Many users reduce the number of CA events by using a fixed pressure rather than a range.
Fred
RE: Impact of Mask Leaks on AHI?
(04-14-2018, 08:56 PM)bonjour Wrote: Neither night is showing significant leaks, though they look like they may be mouth breathing, not a concern unless they are disturbing your sleep.
Night 2 your closeup is near the end of your sleep period and could be SWJ (that is Sleep Wake Junk).
Keep in mind that when you are using EPR, it is the EPAP/Exhale pressure, the lower of the 2 pressures that is supporting your obstructive apnea.
As you have noted you have a mix of roughly equal proportions of Central apnea and Obstructive Apnea. I don't thing your CA is high enough that a Dr would consider treating based on the numbers. It can be done but it would likely be based on how you feel rather than the numbers.
The rule of thumb is to increase pressure to treat OA events and to lower it to treat CA events, at least on CPAP devices. Many users reduce the number of CA events by using a fixed pressure rather than a range.
I tried one of my wife's spare Mirage FX nasal masks last night. It did seem to reduce leakage some, but when it did leak it annoyed me more than my P10. I lasted until about 2:30 and then switched back to the P10. Results below for comments.
OA events improved and CA ratio went higher. There were no changes in any pressure settings. EPR was only used in the ramp mode prior to sleep. Fred, I would be interested in your comments on how a VAuto might improve my CA numbers? I suspect I can get one. I have no insurance so it is only money, and between my wife and myself, we probably should have a spare machine. Her S9 has about 10,000 hours on it now, and could become the spare. She would inherit my new A10, and I could buy the VAuto if that would be of some help.
I'm moving to essentially a fixed pressure anyway. I think I will move the minimum up to 10 cm, and the max never goes to the 11-12 range even though it is set for 13 max. I'm just leaving it there for now to see where the machine wants to go.
04-15-2018, 07:35 PM
(This post was last modified: 04-15-2018, 07:35 PM by Ron AKA.)
RE: Impact of Mask Leaks on AHI?
(04-14-2018, 06:35 PM)Walla Walla Wrote: It might of been you waking up but I think your missing the point about the flow waveform and leaks. Think in terms of sound. If there is no other noise you can hear a whisper across the room. Now blast a radio and you can't hear the whisper all you hear is the radio. It's the same thing with flow. If the leak is too large(radio) it doesn't detect the disturbance(whisper) due to the strong flow caused by the leak.
The problem I am having in trying to convince myself of that is that I have looked over a number of gray high leakage events, and in every one, there is a very clean undistorted flow trace. It looks just normal. I can't convince myself that the machine can make up a normal wave form. It can make up garbage, but the flow trace is not even noisy. On the other hand I can easily see that a leak could mask snoring in theory. Snoring is an audible signal and noise from a leak certainly could mess it up. But even there I suspect they have a pretty narrow band filter on the audio pickup for snoring and ignore frequencies other than the typical low frequency snoring sound.
RE: Impact of Mask Leaks on AHI?
I am very new to this treatment (cpap, bipap which ever) and also occasionally have issues with mask or pillow leaks however I would have thought that the ratio of mask leakage is relatively small when compared to the bleed ratio that the masks or pillows have? is this not the case. As I say I am very new to this only commenced treatment a month ago so I am interested to see how this thread goes.
RE: Impact of Mask Leaks on AHI?
(04-15-2018, 07:56 PM)ghce Wrote: I am very new to this treatment (cpap, bipap which ever) and also occasionally have issues with mask or pillow leaks however I would have thought that the ratio of mask leakage is relatively small when compared to the bleed ratio that the masks or pillows have? is this not the case. As I say I am very new to this only commenced treatment a month ago so I am interested to see how this thread goes.
I've only tried three masks; Mirage Quattro full face, Mirage FX nasal, and AirFit P10 nasal pillows. I have not seen specifications numbers, but my perception is that there is a very high flow of bleed air from the Quattro, less on the FX, and least on the P10. But that is purely based on holding my hand around it when I am not breathing.
04-15-2018, 09:04 PM
(This post was last modified: 04-15-2018, 09:04 PM by Walla Walla.)
RE: Impact of Mask Leaks on AHI?
Vent rates for Resmed P10
pressure(cm) Flow L/Min
4 / 20
8 / 29
12 / 37
16 / 43
20 / 49
Just in case you wanted to know.
RE: Impact of Mask Leaks on AHI?
Last nights results are below. Still having problems with mask leaks. My homemade Tensor bandage chin strap is not working well, and keeps slipping off. I'm sure there is leakage through an open mouth at times. The straps on the P10 although I am using the goofy clips they provide, are not staying in place either. Hopefully when I get my real chin strap I can make some progress on those issues. May resort to using Velcro to hold the mask straps to the chin strap harness. Really hope I do not have to resort to a full face mask.
That said, I think I am closing in on a potential final setting for the A10. Readings improved last night but that may be more good luck than anything else. Surprisingly centrals went down. It is my observation that there is little difference in the appearance of a central and a obstructive event. You can see that the A10 is is doing the 4 Hz pressure pulses and using that to distinguish between the two types of events. I presume they are measuring the amplitude of the 4 Hz pressure response. If it is low they flag as a central, and if it is higher they flag as a obstructive. Seems to me at times they look virtually identical from a little bit further out, and wonder if they are splitting hairs, and some of the centrals are really obstructive. I have the occasional unclassifed but not many. I guess time will tell.
At this point it is looking like the final setting will be a pretty narrow range with a minimum of about 10.4 and maximum of 12.6, with no EPR during the sleeping period.
