Should i be worried about flow limitation?
I just received my second machine on Friday (1/29/16) after being diagnosed in 2009. I went from a M Series to a ResMed AirSense 10 Autoset. I downloaded the ResScan software to look at my data and noticed a graph called Flow Limitation. Should i be worried about the information on this graph. My AHI the past three nights have been .7, .9, & 1.4. The machine is currently in CPAP mode with a pressure of 16. i ask this question because if my AHI numbers are low, then why is the Flow Limitation not a flat line? The graph shows a line with a lot of spikes. Thank you in advance for any enlightenment you can give me on this subject.
02-01-2016, 08:25 PM
(This post was last modified: 02-01-2016, 08:31 PM by pholynyk.)
RE: Should i be worried about flow limitation?
This is an interesting question you have, and I think it you would get better answers in the General Forum instead of here. It's my impression that this forum is intended for questions about your account, rather than apnea therapy.
I have asked a Moderator to move this thread to where it will get the most response.
Edited to Add:
Well, I would have asked, but I can't find one on-line right now. I trust one will come along and do whatever is required.
I'd really like to learn more about ResMed's ideas about Flow Limitations myself.
RE: Should i be worried about flow limitation?
Flow limitation is a precursor to obstructive events and is a narrowing or change in shape of the airway. There is a (very old) Resmed page which includes a brief description here:
http://www.resmed.com/int/clinicians/com...nc=dealers
There's also quite a good video (again by Resmed) here:
https://www.youtube.com/watch?v=3Ehb7U78P5w
RE: Should i be worried about flow limitation?
I am not a Doctor of Medicine: so take what I say as information from a user but not a diagnosis.
Generally with your low AHI, I would suggest that you don't have much to worry about with regards to flow limitations.
Generally, a flow limitation indicates that your brearhing system (nose, pharnyx, and bronchial tubes) are starting to close off. In the extreme, if they were to close, you would have an obsructive sleep apnea. However the APAP has detected it and is starting actions, normally a pressure rise, to prevent it in the future. Since it is only a flow limitation and not a complete closure, you should be doing OK.
Continued good luck with your new APAP!
Walt
Walter W. Olson, Ph.D., P.E.
Mechanical Engineering
Professor Emeritus, Professional Engineer
RE: Should i be worried about flow limitation?
Thanks to everyone for your help. I am new to this forum and glad to see there are helpful people here!
RE: Should i be worried about flow limitation?
When in CPAP mode the machine does not take action and with your low AHI you are having almost no apneas or even hypopneas. All this is great!
No idea about the flow restrictions but they are not stopping you from breathing.
You may want to look into APAP mode and see how you like it
New toys are a good thing.
RE: Should i be worried about flow limitation?
(02-02-2016, 04:56 AM)DeepBreathing Wrote: Flow limitation is a precursor to obstructive events and is a narrowing or change in shape of the airway. There is a (very old) Resmed page which includes a brief description here: http://www.resmed.com/int/clinicians/com...nc=dealers
There's also quite a good video (again by Resmed) here: https://www.youtube.com/watch?v=3Ehb7U78P5w
Nice video. ResMed's a quality company. I love the slow clear simple tone of the audio. It's designed for someone like me.
RE: Should i be worried about flow limitation?
Thanks again for your input! I will be switching to APAP this weekend. I wanted to get a baseline with the new machine so i could see if there was improvement or not after the switch. I will also be reading the article and watching the video.
RE: Should i be worried about flow limitation?
I find the flow limitation function on Resmed machines to be quite confusing. I frequently get obstructive apneas or hypopneas flagged, yet it does not show any flow limitation before or during these events.
How can you have one without the other?
RE: Should i be worried about flow limitation?
(02-04-2016, 09:36 AM)EuroGuy Wrote: I find the flow limitation function on Resmed machines to be quite confusing. I frequently get obstructive apneas or hypopneas flagged, yet it does not show any flow limitation before or during these events.
How can you have one without the other?
Flow limitation and snores are well known precursors to potential apnea events, and the machines respond quickly with increased pressure based on that general rule. However not everyone has flow limitation prior to obstructive apnea or hypopnea, and some people can have persistent flow limitation without eventual apnea. So for every rule there are numerous exceptions?
Treating your particular needs is part of the art of setting up the machines. Where an individual like yourself does not express flow limitation, snores or volume changes prior to apnea, a higher minimum pressure is usually required, because the machine does not pick up the usual queues of impending events. There is a fair amount of mystery (proprietary algorithms) in how the machines modulate pressure. If you experience obstructive events, and the machine does not increase pressure ahead of them, then increased minimum pressure is you best solution.
