RE: FFM Vs. Nose Pillows - Is there a pressure difference?
(05-01-2015, 04:44 AM)Tsparky Wrote: With a FFM my mouth opens in the mask and air escapes into the mask and exits out the larger mask port holes - feels like less pressure delivered to my sinus, throat, lungs, etc., with the NP, smaller port holes, I receive the same pressure up the nose with no air escaping my mouth but the NP pressure feels much stronger to my sinus, throat, lungs, etc..
It may feel different, but the pressure is the same.
If your mouth opens with the FFM the pressure will be the same, but less of the airflow will be in your nose. The pressure in the nose will be the same, but you will feel less flow.
The FFM pushes on your lower jaw. This may shift your jaw backwards and make your apnea a bit worse.
Since your machine is an auto, it's also possible it's adjusting to a different pressure when you have the FFM vs. the nasal mask.
I think the effect of the mask type setting on the CPAP machine is fairly minor. I think it affects how it calculates apnea and how it tries to keep the pressure in the mask constant in the short term as you inhale and exhale. I don't think it increases or decreases the average pressure.
Get the free OSCAR CPAP software here.
Useful links.
Click here for information on the main alternative to CPAP.
If it's midnight and a DME tells you it's dark outside, go and check it yourself.
RE: FFM Vs. Nose Pillows - Is there a pressure difference?
Thanks.
05-01-2015, 03:52 PM
(This post was last modified: 05-01-2015, 04:16 PM by zonk.)
RE: FFM Vs. Nose Pillows - Is there a pressure difference?
(05-01-2015, 10:33 AM)Tsparky Wrote: The RESMED compensating for different mask types seems to make sense. Anyone know where I can fined the "vent leak rate" for specific masks? ResMed masks: http://www.resmed.com/content/dam/resmed...er_eng.pdf
Respironcis masks: http://www.healthcare.philips.com/pwc_hc...111027.pdf
Every time you tell the machine the type of mask you're using, the machine assume you're using ResMed mask
But not a lot of difference between ResMed masks and other manufacturers masks, just they want to be certain that you only buy their products and your money end up in their pockets
For us using ResMed machines, mask vents leak rate does not matter much for us as the machine report unintentional leak (mask and mouth leaks) on the LCD sleep report and on the SD card
ResMed tell us 24 L/m is an acceptable number (but I like to see mine much lower) and the machine can deliver the right therapy within this range, higher leak rates affect the accuracy of the data and therapy effectiveness
05-04-2015, 07:20 AM
(This post was last modified: 05-04-2015, 07:21 AM by Tsparky.)
RE: FFM Vs. Nose Pillows - Is there a pressure difference?
(05-01-2015, 03:52 PM)zonk Wrote: (05-01-2015, 10:33 AM)Tsparky Wrote: The RESMED compensating for different mask types seems to make sense. Anyone know where I can fined the "vent leak rate" for specific masks? ResMed masks: resmed.com/content/dam/resmed/global/documents/products/serviceandsupport/pressurevsflowrates/1016852_mask_pressure-flow-rates_amer_eng.pdf
Respironcis masks: healthcare.philips.com/pwc_hc/main/homehealth/sleep/masks/pdf/Intentional_leak_rates_for_masks_and_exhalation_ports_20111027.pdf
Every time you tell the machine the type of mask you're using, the machine assume you're using ResMed mask
But not a lot of difference between ResMed masks and other manufacturers masks, just they want to be certain that you only buy their products and your money end up in their pockets
For us using ResMed machines, mask vents leak rate does not matter much for us as the machine report unintentional leak (mask and mouth leaks) on the LCD sleep report and on the SD card
ResMed tell us 24 L/m is an acceptable number (but I like to see mine much lower) and the machine can deliver the right therapy within this range, higher leak rates affect the accuracy of the data and therapy effectiveness
Zonk, So if my NP delivers 40 L/min at 14 CM H2O and my FFM delivers 44.5 L/Min at 14 CM H2O, assumes no leaks, then I am receiving 4.5 L/min more air with the NP. Does the ResMed machine compensate for this with the selection of NP/FFM? Seems the tables are saying that my numbers above are the compensated numbers so more volume of air would equal more pressure???
Thanks for you feedback I find it very helpful. Tsparky
RE: FFM Vs. Nose Pillows - Is there a pressure difference?
(05-04-2015, 07:20 AM)Tsparky Wrote: Zonk, So if my NP delivers 40 L/min at 14 CM H2O and my FFM delivers 44.5 L/Min at 14 CM H2O, assumes no leaks, then I am receiving 4.5 L/min more air with the NP. Does the ResMed machine compensate for this with the selection of NP/FFM? Seems the tables are saying that my numbers above are the compensated numbers so more volume of air would equal more pressure???
Thanks for you feedback I find it very helpful. Tsparky
Tsparky...those are the leak rates, I do believe. The NP is intentionally leaking 4.5 L/m less than the FFM.
In the settings of the resmed machines, this intentional leak rate is important as the machine uses this information to calculate the unintentional leak rate. You need the intentional leak to flush out the CO2 you are exhaling...and that will vary with each mask / vent type. But...having a high unintentional leak rate means you may not be getting as good a treatment as you would like...the air supposed to be keeping your pressure up and airway open is leaking out.
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
RE: FFM Vs. Nose Pillows - Is there a pressure difference?
(05-04-2015, 05:04 PM)PsychoMike Wrote: Tsparky...those are the leak rates, I do believe. The NP is intentionally leaking 4.5 L/m less than the FFM.
In the settings of the resmed machines, this intentional leak rate is important as the machine uses this information to calculate the unintentional leak rate. You need the intentional leak to flush out the CO2 you are exhaling...and that will vary with each mask / vent type. But...having a high unintentional leak rate means you may not be getting as good a treatment as you would like...the air supposed to be keeping your pressure up and airway open is leaking out.
The mask type setting on the Resmed machines is to provide the machine with the mask pressure drop to provide the correct pressure to the mask since the pressure is measured at the machine.
The unintentional leak rate is calculated in a far more complex, technical manner. It would not do to just use the theoretical vent flow at pressure. Hole size variations, foreign materials in the vents, vent hole shape anomalies would all adversely effect the unintentional leak rate calculations just using the design hole size and number. Even worse might be extra turbulence just outside the vents caused by impingement by sheets, pillows, arms, et cetera.
Or one could take Philips Respironics position and say, "OK here is your total leak (intentional + unintentional), you figure it out". Makes it less controversial.
Best Regards,
PaytonA
|
