flow Rate

I'm confused about Flow Rate in SleepyHead software. Specifically, why does my flow rate start out really solid and compressed every night then it gets less solid about half way through the night. Is this a bad thing? Shouldn't the flow rate stay the same? Is it better to be all solid black (like in the beginning) or black lines (like towards the end)?

Java wrote:I'm confused about Flow Rate in SleepyHead software. Specifically, why does my flow rate start out really solid and compressed every night then it gets less solid about half way through the night. Is this a bad thing? Shouldn't the flow rate stay the same? Is it better to be all solid black (like in the beginning) or black lines (like towards the end)?

Hi Java!

A 150 pound person, on average, at rest, uses about 6 liters per minute (lpm) of air. I have run across studies which seem to indicate that those with OSA on average use above 12 lpm of air. From what I have read and knowing my own experience I think that messed up breathing reflexes (metabolic need vs air used) are possibly part of the genesis of OSA and certainly a consequence of OSA.

We tend to over breath.

You start on PAP as I used to I think, and as I tend to even now. I do not know why, but when I dawn the PAP and lay down the first several minutes are spent getting the breathing back under control. It wants to take off - to let the pressure send the air use up into the stratosphere.

Normally I simply breath in gently for two counts, breath out gently for two counts, and pause for two counts. As time moves toward the middle of November memories a a bad assault and robbery will accentuate my tendency to over breath – so the pause time I will probably extend at first. I know I am doing it right when my heart rate goes down and my feet get warm.

When looking at flow rates check the leak rates at the same time. High leak rates tend to warp the flow rates downward falsely.

I also look at my minute volumes. For me (just under 200 pounds) I get a bit concerned if the average is above 7 and 95% above 10. If the breathing rate gets high the respiratory effort will likely cause arousals – you may see periodic breathing – you may see hypocapnic central apneas (Clear Airway Apneas preceded by heavy air flows as you would see them using SleepyHead – remember – you can “zoom in” on any event by dragging across it and go back to the full view by dragging across the top chart).

This is time at rest. You really should not be using too much air.

Have a great week!

Todzo

I think it is a function of the compression of the flow that gives the appearance of the light and dark flow lines.
I just looked back through about a month's worth and all mine have a similar light at dark pattern but when I zoom in really close they all look alike.
It has pretty much always shown up like that. Mine look like yours without the breaks in therapy. Over a years worth of reports and they all will have some of that varying. Some more than others. I don't think it means anything one way or the other.

I have a couple of examples in my ugly leak thread.
viewtopic.php?f=1&t=76445&p=698087&hili ... ne#p698087

[quote="Todzo"
A 150 pound person, on average, at rest, uses about 6 liters per minute (lpm) of air. I have run across studies which seem to indicate that those with OSA on average use above 12 lpm of air. From what I have read and knowing my own experience I think that messed up breathing reflexes (metabolic need vs air used) are possibly part of the genesis of OSA and certainly a consequence of OSA.[/quote]
Todzo,

Can you point me to a source for this information?

I'm not questioning your statements; rather I'd like a source so that I might be able to figure out how some of this stuff might apply to a 110 pound female instead of the proverbial 150 pound person.

robysue wrote:[quote="Todzo"
A 150 pound person, on average, at rest, uses about 6 liters per minute (lpm) of air. I have run across studies which seem to indicate that those with OSA on average use above 12 lpm of air. From what I have read and knowing my own experience I think that messed up breathing reflexes (metabolic need vs air used) are possibly part of the genesis of OSA and certainly a consequence of OSA.

Todzo,

Can you point me to a source for this information?

I'm not questioning your statements; rather I'd like a source so that I might be able to figure out how some of this stuff might apply to a 110 pound female instead of the proverbial 150 pound person.[/quote]

Hi robysue!

Data taken at the hospital or in the doctors office is affected by so many things (e.g. "white coat effect") - and your particular lung efficiency, the altitude where you breath, and what you ate for dinner last night along with how many miles you moved how fast (metabolic efficiency) would all need to be factored in to figure out how it may apply to you right now.

My point for Java was simply that our air use at night, at rest, is not great - while - PAP tends to make it easier to breath more air and indeed tends to make breathing "take off" for many of us. My "Minute Volume goals" are based on years of looking at my own data (often gathered while using Pulse Oximeter Guided Breathing), what appears along with the Minute Volumes usually - and how I feel in the morning, my performance during the day - BP, sugar, mind test performance...

If you really want to find out the minute volumes that are "in the range" of good for you I think a good start would be to strap on your PAP, lay quietly for at least half an hour while using your pulse oximeter to find the lowest heart rate using breathing as a control. In my case I know the SpO2 percentage which will guide me in to very close in your case you may have to practice a day or two to be able to get the hang of controlling your breathing on PAP which I found much harder than not on PAP. At any rate I do believe heart rate is a good guide to find the best breathing air use. Do be careful to breath from your diaphragm – breathing form is likely important.

Have a lot of fun!

Todzo

Zoom in by clicking on the suspect areas with your mouse. You can't really tell anything at that scale.

If you're talking about the area where it looks sort of gray, that may just be an "artifact" of how the data is shown on the screen. Sort of like a Moire pattern looking through a screen door.

Todzo wrote: If you really want to find out the minute volumes that are "in the range" of good for you I think a good start would be to strap on your PAP, lay quietly for at least half an hour ...

No way am I going to do that. It's a surefire recipe for aerophagia.

That's actually part of what fed the insomnia monster for so long: Pre-CPAP my latency to sleep was long---as in 40-45 minutes of (glorious) daydreaming and nuzzling against my sleeping hubby. But wearing the hose for as little as 20 minutes while awake---no matter how quiet and calm and collected I am---results in a tummy full of air.

archangle wrote:Zoom in by clicking on the suspect areas with your mouse. You can't really tell anything at that scale.

If you're talking about the area where it looks sort of gray, that may just be an "artifact" of how the data is shown on the screen. Sort of like a Moire pattern looking through a screen door.

Hi archangle!

To drag across an area with the mouse set the cursor at the beginning of the aera - right click and hold the right mouse key (press down on the right mouse key and hold it) and move the cursor across the area you wish to see (the incident plus some time prior and after) - then - let the mouse key up.

There is probably a shortcut key but usually I just drag across the entire top of the page graph to reset all graphs to show the entire night.

Have a lot of fun!

robysue wrote:

Todzo wrote: If you really want to find out the minute volumes that are "in the range" of good for you I think a good start would be to strap on your PAP, lay quietly for at least half an hour ...

No way am I going to do that. It's a surefire recipe for aerophagia.

That's actually part of what fed the insomnia monster for so long: Pre-CPAP my latency to sleep was long---as in 40-45 minutes of (glorious) daydreaming and nuzzling against my sleeping hubby. But wearing the hose for as little as 20 minutes while awake---no matter how quiet and calm and collected I am---results in a tummy full of air.

Hi again robysue!

When I started doing Pulse Oximeter Guided breathing I was at a pressure of 15 - now the pressure that works for me for a current AHI=0.45 is 8 cm/H2O.

Do you think that reducing your pressure by almost half might help with air getting less air from the PAP into your tummy (aerophagia)?!

But as I think back to those starting days I do recall that I wore the Pulse Oximeter almost constantly for about three months. I did not try using it with my CPAP for at least two weeks and - after noting how hard it was (I do hate those pressure pulses) - I decided to wait an additional week or so before my next try..

You are right, I am sure you do not have the time nor the patience to make any sort of Pulse Oximetry Guided Breathing to work for you.

Oh well,

Todzo

There's nothing obviously wrong about any part of your chart. What's your AHI?

What particular time periods are you worried about?

The spotty bit around 9 PM is probably just an artifact of how SH displays the data. Zoom in like I said and see if the spottiness goes away or you see anything strange when you zoom in.

archangle wrote:There's nothing obviously wrong about any part of your chart. What's your AHI?

What particular time periods are you worried about?

The spotty bit around 9 PM is probably just an artifact of how SH displays the data. Zoom in like I said and see if the spottiness goes away or you see anything strange when you zoom in.

My AHI is is 1.03 average. When I zoom in, it looks normal, it's just when I zoom out I see the spotty part begin around 9 and it lasts till I wake up. I guess it is an artifact of how SH displays the data. Just looked odd and kind of freaked me out when I first saw it.

Todzo wrote: A 150 pound person, on average, at rest, uses about 6 liters per minute (lpm) of air. I have run across studies which seem to indicate that those with OSA on average use above 12 lpm of air. From what I have read and knowing my own experience I think that messed up breathing reflexes (metabolic need vs air used) are possibly part of the genesis of OSA and certainly a consequence of OSA.

I, too, would like to see the sources for this.

A normal tidal volume is ~5-7 ml/kg ideal body weight, normal respiratory rate ~12, and minute ventilation



However, these are volume measurements. and the OP's question is about flow.

deltadave wrote:A normal tidal volume is ~5-7 ml/kg ideal body weight, normal respiratory rate ~12, and minute ventilation



However, these are volume measurements. and the OP's question is about flow.

And V_T equals tidal volume? And f = respiratory rate?

robysue wrote:

deltadave wrote:A normal tidal volume is ~5-7 ml/kg ideal body weight, normal respiratory rate ~12, and minute ventilation



However, these are volume measurements. and the OP's question is about flow.

And V_T equals tidal volume? And f = respiratory rate?

Roger on that!