Respiratory Rate not showing accurately in Sleepy Head?

Using a ResMed AirCurve 10 ST-a in ST mode. While usinga P10 pillows the respiratory rate chart looks accurate. When I use my full face F&P Simplus (yes I changed the mask type setting) my median respiratory rate ends up very similar but the charts also show huge sustained spikes to like 35-40bpm and stay there for a long time. This can happen with no corresponding abnormalities in other values such as tidal volume. I’m using the FFM because for whatever reason I spontaneously trigger the breath more and it helps my muscles feel more rested in the morning as opposed to when I use a nasal mask.

How can I use sleepyhead to find out whether the sustained RR spikes are real or not?

Hi raisedfist,

If you already have Sleepyhead, and if you click-and-hold on any of the charts, and then slide right a bit, and then let go, the bit of the chart that you have just highlighted expands to fill the whole width.

Once you have 'zoomed-in' on that chart, you can also click-and-hold on a time, and again slide right to one or two minutes later, and then let go – and then you have what's going on in one or two minutes.

In this case, the 'flow' chart is what needs to be zoomed in on.

What I would be looking for is what's called 'a saw-tooth curve'. This is minor variation which occurs in about 12 per cent of people, and is of no great clinical significance.

It seems that Sleepyhead and other CPAP-data-reading software are sometimes fooled by this variation into giving a resp rate that is two or three times the true rate.

So, it might be that. Or it might be something else. Can't tell until we see a zoomed-in on chart.

rick blaine wrote: ↑

Fri Aug 24, 2018 10:21 am

Hi raisedfist,

If you already have Sleepyhead, and if you click-and-hold on any of the charts, and then slide right a bit, and then let go, the bit of the chart that you have just highlighted expands to fill the whole width.

Once you have 'zoomed-in' on that chart, you can also click-and-hold on a time, and again slide right to one or two minutes later, and then let go – and then you have what's going on in one or two minutes.

In this case, the 'flow' chart is what needs to be zoomed in on.

What I would be looking for is what's called 'a saw-tooth curve'. This is minor variation which occurs in about 12 per cent of people, and is of no great clinical significance.

It seems that Sleepyhead and other CPAP-data-reading software are sometimes fooled by this variation into giving a resp rate that is two or three times the true rate.

So, it might be that. Or it might be something else. Can't tell until we see a zoomed-in on chart.

You can also use the arrows, up to zoom in, down to zoom out, left and right to... well, left and right.

Right click the 'flow rate' title on the left, then 'dotted lines' and turn on the zero line.

SH is very dumb when it comes to RR, counting pretty much any crossing of the zero to be a breath for RR, even if it's just cardiac fluctuations.

Not sure if I did this right, I'm kind of a noob when it comes to SleepyHead.

raisedfist wrote: ↑

Fri Aug 24, 2018 8:00 pm

Not sure if I did this right, I'm kind of a noob when it comes to SleepyHead.

For that minute, from 2:43:40 to 2:44:40, I get 36. So it looks like SH is reading a little high.

palerider wrote: ↑

Fri Aug 24, 2018 9:18 pm

raisedfist wrote: ↑

Fri Aug 24, 2018 8:00 pm

Not sure if I did this right, I'm kind of a noob when it comes to SleepyHead.

For that minute, from 2:43:40 to 2:44:40, I get 36. So it looks like SH is reading a little high.

Hm well sleepyhead shows my RR as very elevated for a lot of times using the FF mask...but not really ever using the nasal pillows mask on the same pressures...I guess it could be excessive mouth breathing versus nasal breathing.

Hello again, raisedfist,

Hmm. That isn't the classic 'saw-tooth curve'. To be honest, I don't know what it is.

And ... I note your machine is designated as a ventilator, as opposed to a CPAP machine ... and I know very little about those.

But I do know that a RR of 40 is considered high.

I suggest you see your doctor, or whoever provides your ventilator support, and get clarification and/ or adjustment there.

rick blaine wrote: ↑

Sat Aug 25, 2018 3:28 am

Hello again, raisedfist,

Hmm. That isn't the classic 'saw-tooth curve'. To be honest, I don't know what it is.

Part of the issue is that he has a very long TiMin on his machine there, longer than his lungs will accept air. (I've looked at his data in more detail). so it pops up to ipap, he inhales all he can, and then there's that little bounce while the machine stays at ipap, before finally dropping back to epap.

palerider wrote: ↑

Sat Aug 25, 2018 8:27 am

rick blaine wrote: ↑

Sat Aug 25, 2018 3:28 am

Hello again, raisedfist,

Hmm. That isn't the classic 'saw-tooth curve'. To be honest, I don't know what it is.

Part of the issue is that he has a very long TiMin on his machine there, longer than his lungs will accept air. (I've looked at his data in more detail). so it pops up to ipap, he inhales all he can, and then there's that little bounce while the machine stays at ipap, before finally dropping back to epap.

Interestingly enough I have been testing out a Respironics machine on and off recently. The criteria for hypopneas is different, more sensitive, and the machine will flag hypopneas while my ResMed machine just says zero AHI every single night. If I use the spontaneous/timed mode on the PR, since there is no Ti min on the machine, I just breathe for however long my body allows, my AHI is very low consisting of hypopneas. And the AHI correctly decreases when I increase the IPAP. However, if I flip over to pressure control (PC) mode, where the Ti is fixed/constant for all breaths on the PR, my AHI increases the longer I force the Ti to be. For instance, if I put Ti as 1.5s in PC mode, my AHI ends up being like 10. If I lower Ti to 1.2s, my AHI is about 6.

Sucks because the triggering/cycling seems more comfortable for ME on the PR machine - it's automatic. My guess is on the ResMed I need to tweak both settings. But the fact that I can't set a Ti Min and Ti Max is bloody annoying.