Flow Limitation Question

I'm looking for some input on my flow limitation graph from Sleepy Head. My AHI is 0 but I don't feel rested and lately I haven't been able to keep my mask on for more than a few hours at a time. After reading another post regarding flow limitations I decided to check mine but I don't know what I should be looking for. BTW the three large leaks were from me taking off the mask to scratch an itch. Any input is greatly appreciated.

Bump

Other than that little blip of flow limitation at the beginning of the night your flow limitations are very minimal to none.
Mine look about like yours so I can't easily show you one that is more exciting. I will poke around a bit to see if I can spot one that is more exciting.
There's not really much to be said about your FL graph. It's pretty boring.

I poked around on the forum and found some ugly FL graphs with ResScan but not really many with SleepyHead reporting to show you apples to apples.
I did find this one that does have about 3 FL spikes

Thanks Pugsy! Should I focus on the wave height or the frequency of limitations?

Pugsy wrote:I poked around on the forum and found some ugly FL graphs with ResScan but not really many with SleepyHead reporting to show you apples to apples.
I did find this one that does have about 3 FL spikes

all my FL charts look pretty much like that just posted about it on my other thread about the weird data.

Here's another FL chart from SleepyHead. The FL index that night was 95% = 0.14, Max= 0.33 (wish I knew what these numbers actually mean):

Here is my FL on SH from the beginning of 2012. Note that it covers more than 9 hours of sleep:



The S9 machines measure FL by the shape of the respiration waves shapes. A rounded top of wave is good but flattened top is bad. The FL includes UAR Syndrome and RERA Syndrome. The S9 in APAP mode would raise the pressure if it encountered FL to overcome it.


See here ,in ResScan, the shapes of some of my respiration waves. Some have rounded top and others flattened. The S9 decides on the number of the flattened shapes within one hour of sleep and shows it on the FL scale by using icons.

ROUNDED TOPS:



FLATTENED TOPS:



There is nothing that we can do to improve the FL (besides surgery) but to continue PAPing.

@Kaiasgram me too! Hopefully we can get some answers.

@avi123 thank you! When I get home tonight I'll try to zoom in on the sleepy head graph and see if I have flat or rounded wave tops. I understand that if a flow limitation is long enough it becomes an apnea or hypoapnea but how many flat waves would suggest UARS or another sleep issue?

Ok, I think I've figured out how to upload a close up view of my flow limitation date. The first screenshot shows the whole graph so you can get a feel for the whole night. The close up shows the wave pattern for a very short time period. To my very inexperienced eye most of the waves have flat tops. Any thoughts or suggestions are greatly appreciated!

Pap365 wrote:Ok, I think I've figured out how to upload a close up view of my flow limitation date. The first screenshot shows the whole graph so you can get a feel for the whole night. The close up shows the wave pattern for a very short time period. To my very inexperienced eye most of the waves have flat tops. Any thoughts or suggestions are greatly appreciated!

Pap, you're showing a closeup of your Flow Limitation graph. The "flat top waves" description of flow limitation pertains to your Flow Rate graph in SleepyHead where it shows the waveform of your inhalations and exhalations. That would be the one to post -- pick a section where your Flow Limitation graph shows an increase in flow limitation, and then post your Flow Rate graph for that same chunk of time.

From SH glossary:

FL
Flow Limitation is a partial obstruction of the airway as detected by a change in the shape of the flow signal.
Flow Limitation Detection in Respironics System One..Auto Mode Only scoring only.Straight CPap or Straight BiPap modes does not score this event. The device looks for relative changes in the peak, flatness, roundness, or shape (skewness) of the inspiratory portion of the airflow waveform. These changes are observed both over a short period of time (groups of 4 breaths) and over a long period of time (several minutes). Statistical measures are used to help minimize false event detection while allowing the device to be sensitive to even small changes.

Flow Limitation Index
Changes in flow limitation are recorded as events. The Flow Limitation Index is calculated by the total number of flow limitation events per night divided by the hours of use. Note: The average is calculated by taking the total number of events divided by the number of therapy days. This can be used to indicate if there has been a significant degradation in the flow signal, resulting in a pressure increase. This value is only reported on auto pressure machines.

Here is the flow rate graph.
@avi thanks for the definitions. Why don't machines in cpap mode record flow limitation data?

Pap, it looks like the flow limitation shows up in your breathing waveform -- the top of the inspiration curve gets flatter. Actually I was just looking at the ResScan report interpretation guide and when the flat top also has that saw-tooth appearance (the two inhalations after that tall peak in your graph) it apparently indicates snoring. I'd be curious if your snore graph shows snoring at that point in time.

I'm trying to find out the same thing you are, that is, whether I have flow limitation significant enough to be affecting my sleep quality and how I feel during the day. It's proving tricky. One way to find out would be to experiment with a higher pressure for a while (which theoretically at least would reduce flow limitation) and see if you start to feel better. I'd have to go to a bilevel machine to experiment with that because I get disruptive aerophagia when I go higher than my current pressure. If I'm seeing your pressure range correctly you have a min pressure of 8 and a max pressure of 14 -- I'd ask Pugsy if you were going to try tweaking your pressure whether it would be better to bump up your minimum pressure or your max pressure, a lot of this is still pretty new to me so I'd rely on the 'seniors' here for advice.

*SleepyHead does show a Flow Limitation graph when your S9 machine is in CPAP mode. It's the Respironics machines that don't show FL in CPAP mode according to the Sleepyhead glossary quoted above.

Here's the same time frame with the snore graph. It does appear that there was some snoring right after that spike in the flow rate. It's frustrating isn't it? You get diagnoses with OSA and the drs tell you no worries we can treat the OSA and you'll feel better. So you go through the challenges of finding "your" mask, getting a data capable machine and software all the while coping with the fact that you have OSA only to find that you are still not rested. AARGH! Interesting idea to increase my pressure. Thanks for sharing what you know. It's nice to know Iim not alone with this challenge!