[Diagnosis] Can someone explain

[weeble]

Hi again,
Sorry if this has been asked before - but can someone explain to me what exactly Flow Limitation is?

Last night my readings were all over the place and I noticed that my snoring was right up and above the very loud level. Looking back, when the flow limitation is steady, the snoring is minimal
Thanks in advance

[lonnieb]

hi weeble: I did a search and came up with this ,I didn't know either
Wikipedia: "Respiratory minute volume (or minute ventilation, or flow of gas) is the volume of air which can be inhaled (inhaled minute volume) or exhaled (exhaled minute volume) from a person's lungs in one minute...A normal minute volume is about 5–8 liters per minute in humans."


http://www.resmed.com/in/clinicians/comp...nc=dealers

[Sleepster]

From our Apnea Board Wiki ...

Flow Limitation - Partial closure of the upper airway, which impedes the flow of air into the lungs.

[zonk]

Basically flow limitation is like having a mini apnea (less than the 10 seconds required for an apnea to be scored)
S9 AutoSet respond to flow limitation by increasing pressure but not during an apnea while the S9 Elite limited to whatever pressure its set

ResScan symbols:
Mountain ......= good
1/2 Mountain = OK
Flat .............= bad

[greatunclebill]

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.

all terms are explained in the sleepyhead glossary. find it when you open sleepyhead by going to the help browser tab and clicking the Glossary of Sleep Disorder Terms link.

also at http://sourceforge.net/apps/mediawiki/sl...e=Glossary

[weeble]

Thanks for the replies - me thinks I may have to dump my elite and get an auto - just a bugger my sleep therapy company only prescribe fixed!

[PaulaO2]

For my current machine, I just had my regular GP write out the script. I didn't do much research ahead of time 'cause I'm an idiot. So a script for a CPAP does not have to come from an expensive sleep doc.

[zonk]

Thanks for the replies - me thinks I may have to dump my elite and get an auto - just a bugger my sleep therapy company only prescribe fixed!

You can get used one from secondwind with or without humidifier
I've noticed flow limitation on my charts when congested
I wouldn't worry about one night but if persists night after night than you can try increase pressure by the smallest increment and see if any difference without compromising sleep quality