what is the significance of respiratory rate

[TedVPAP]

I know what it is but I am trying to understand why my friend's rate is so much higher than mine. My rate is 16-avg, 20-95%. His numbers are about twice mine. There are times where his rate will drop down to mine but for only 15 minutes or so.
His treatment is not yet dialed in (after 2 years with his doctor and DME) so I am trying to help him. His AHI is about 4 but he unknowingly removes his mask after ~4hours every night. I think his CPAP pressure is still too low so he is working his way up slowly. He uses a FF mask and breaths primarily through his mouth due to blocked septum.
Thanks

[ajack]

you also need to see the tidal volume and minute vent, to see where the hickup is. The machine could also be miscounting the breath rate. I would get him to join apneaboard and post some charts.

[Jay Aitchsee]

As Ajack suggests, the RR may not be accurate. In order to verify the RR, can you post a graphic of about 1 minute in duration which compares a typical Flow Rate segment to the RR, something like this?

[rick blaine]

Hi TedVPAP,

First, in respiratory medicine, there is such a thing as a 'saw-tooth' curve on the spirometer (the machine that shows doctors a person's breathing pattern), and it turns up in about 12 per cent of those with obstructive sleep apnea. And it looks like two breaths when it's really only one breath cycle. Now, I don't know if the software on the most popular makes of CPAP machine take this into account. If said software doesn't take it into account - and if your friend does have that pattern - then his 'true' resp rate could be as little as half of what the machine's numerical table shows.

Second, yes, as ajack says, the rate on its own is not all of the story - the tidal volume is just as important. And the combination of resp rate and tidal volume go to give the minute ventilation. For information: the 'normal' resp rate for most people who are at rest is 12-15 per minute; the average tidal volume at rest for a male of my height - I'm 5' 8" - is 440 mil; and the total capacity per minute of a healthy male of, say, 30 to 50 is 6 litres.

Having said all that, doctors would usually want to take a look at someone with a resp rate consistently above 20, to find out why that might be. And if a resp rate over 20 was combined with a pulse rate over 90 and a temperature of 38C or over, that would suggest the person has a serious systemic infection.

[ajack]

Other than a 5 minute dream or something. If it was a real RR of 30 most of the night. I would think there would also be breathing issues when awake. The machine can misread a hiccup in the flow rate as another breath. As Jay said, it needs to be looked at and verified.

[TedVPAP]

Thanks to everyone for your posts.
He says it only happens when using PAP and is otherwise very healthy.
I have asked my friend for access to his SH data so that I can post his charts.
Thanks

[ajack]

most times the breathing regularity will go away with more min pressure, charts will help.

[TedVPAP]

I now have access to my friend Steve's data.
https://imgur.com/a/V61Vu

[USMCVet]

Do you or he have pulse oximeter?
From what little I looked into it mid 20's or higher is cause for concern and depending on oxygen saturation they consider intubating to protect the airway.
Either way I would definitely suggest he see a doctor and ask them.

[USMCVet]

Here is more information
https://www.medscape.com/viewarticle/712242
Something is up for sure.

[TedVPAP]

Here is more information
https://www.medscape.com/viewarticle/712242
Something is up for sure.

Thanks for the link but Steve is mid 40's, healthy, and only pants when using CPAP.

[rick blaine]

Hi TedVPAP,

Thanks for the charts, particularly the one-minute-expanded-out-to-fill-the-width. It is as I thought - the 'overall' pattern is something like 17-to-18 resps per minute.

If you look at the flow-rate diagram, the line dips to minus-60 in a pretty regular fashion - and I think we can take those dips to be the out-breaths. And the curve immediately preceding those bits is mostly uncomplicated. So the breathings out appears to be uninterrupted.

What seems not to be so uninterrupted is the flow in. Each section of the diagram before the next out-breath comes in a two-or-three 'pulls' pattern. And as I understand it, that is the classic 'saw-tooth' pattern. Which according to the literature is an acceptable way to breathe in, no matter how odd it might look in a diagram.

What the transducer in any given XPAP machine does with that kind of flow pattern is something else. The ResMed machine here is clearly counting some of those saw-toothed bits as complete in-and-out cycles.

There is a way to find out if my hypothesis is correct or not - and that is via the expansive chest tube part of the standard PSG.

But since I am not a doctor and I'm just guessing, your friend should go and see his doctor and get it checked out as acceptable or not. Just to put all our minds at rest.

[TedVPAP]

Hi TedVPAP,

Thanks for the charts, particularly the one-minute-expanded-out-to-fill-the-width. It is as I thought - the 'overall' pattern is something like 17-to-18 resps per minute.

If you look at the flow-rate diagram, the line dips to minus-60 in a pretty regular fashion - and I think we can take those dips to be the out-breaths. And the curve immediately preceding those bits is mostly uncomplicated. So the breathings out appears to be uninterrupted.

What seems not to be so uninterrupted is the flow in. Each section of the diagram before the next out-breath comes in a two-or-three 'pulls' pattern. And as I understand it, that is the classic 'saw-tooth' pattern. Which according to the literature is an acceptable way to breathe in, no matter how odd it might look in a diagram.

What the transducer in any given XPAP machine does with that kind of flow pattern is something else. The ResMed machine here is clearly counting some of those saw-toothed bits as complete in-and-out cycles.

There is a way to find out if my hypothesis is correct or not - and that is via the expansive chest tube part of the standard PSG.

But since I am not a doctor and I'm just guessing, your friend should go and see his doctor and get it checked out as acceptable or not. Just to put all our minds at rest.

Thanks Rick. What you say makes sense. It does look like a normal breathing rate clouded by a few subcycles of broken inhalations.
He does have nasal breathing problems so may be that is causing the interrupted inhalation.

[TedVPAP]

Another zoomed in shot

[ajack]

He should have a medical examination to rule stuff out.
The squiggly lines between/during breaths are being counted as full breaths. more than like the pressure is going to go up to settle the breathing, but to rule out some stuff, bring the cpap pressure back to 9, then 8, we want the apnea rate to go up and the breath still to be wrong. Then raise the cpap to 11, then 12 and see what happens after a few nights of each.