Identifying Centrals with ResScan

[Maryland_Mike]

Is there a way to identify centrals with the ResScan software? I only see the apnea flags with what I assume is a number identifying their length in seconds, but nothing to tell if they are centrals. In my sleep studies I've had mostly hypopneas and all of my apneas were centrals.

[twokatmew]

Nope, I wish there were a way....

[cpapqueen1]

There isn't a way. You should have a titration done with the VPAP adapt SV. Does wonders with the centrals.

[dsm]

If you had a Reslink module attached, it gathers much more detailed data and saves it & at least from that you can see a snore index & if there is a period of 'no flow' & there is no snoring or pattern of hypopneas/Flow Lims leading to the 'no flow' you could take a guess that it is 'central'.

The main issue re positively identifying centrals is knowing if the airway is blocked (collapsed) or open at the time of a 'no flow' shown in the charts. The best indication of all is evidence the sleeper is attempting to breath but that requires being wired up like in a sleep study.

The new Respironics machine has implemented FOT (Forced Oscillation Technique) bursts to detect if the airway is open during an apnea & if it thinks yes, it flags a central. FOT was added to a Resmed model called the Autoset Spirit II some years ago but never released on the market. Weinmann in Germany also had an Auto that used FOT (2005-2008) to detect & flag centrals but they appear to have dropped FOT as a technique.

FOT typically sends a short burst of pulses in the delivered air at between 3000 - 5000 cycles per second. If the airway is blocked a particular signal pattern is reelected back, if the airway is open a different pattern gets reflected back. That difference is used to determine if the no-flow is central or obstructive. It is not 100% accurate but pretty good (better than nothing).

Cheers

DSM

[Maryland_Mike]

Wow, dsm, that is fascinating. The reason I'm curious is that all of my apneas in my sleep study were centrals, but the vast majority of my events were hypopneas. I can't get my AHI below the mid-teens and I'm wondering if my hypops are in fact centrals. The weird thing is that I feel fantastic. The other weird thing is that in my titration my AHI was only 1.2. Very strange.

[jdm2857]

Puritan-Bennett (Covidien) uses a different technique to detect centrals on some of their machines. During an apnea the machine "listens" for the user's heartbeat being tranmitted through the air in the airway. If the apnea is obstructive, the airway is blocked, and the heartbeat is not "heard". If the heartbeat is "heard", the apnea is recorded as being central.

[Slinky]

Thank you, DSM, for that information. The manufacturers keep trying, eh?

And jdm, thank you too! I hadn't known that about the Covidiens.

[ozij]

Puritan-Bennett (Covidien) uses a different technique to detect centrals on some of their machines. During an apnea the machine "listens" for the user's heartbeat being tranmitted through the air in the airway. If the apnea is obstructive, the airway is blocked, and the heartbeat is not "heard". If the heartbeat is "heard", the apnea is recorded as being central.

Thank you, DSM, for that information. The manufacturers keep trying, eh?

And jdm, thank you too! I hadn't known that about the Covidiens.

Slinky, you must have fallen asleep in class... jdm is referring to non other than "cardiongenic oscillations" often refered to as "cardiac oscillation". Let me you, my heart sure skipped a beat or 3 when I first saw "cardiac osicallations" in my SilverLining report. I mean, this was telling me I had a heart problem????

[dsm]

Wow, dsm, that is fascinating. The reason I'm curious is that all of my apneas in my sleep study were centrals, but the vast majority of my events were hypopneas. I can't get my AHI below the mid-teens and I'm wondering if my hypops are in fact centrals. The weird thing is that I feel fantastic. The other weird thing is that in my titration my AHI was only 1.2. Very strange.

Mike

If you are suffering predominantly from centrals / hypops, an S8 machine doesn't seem to be the best choice ?.

The normal clinical approach is to put someone with centrals, onto a timed bilevel or an SV machine. BUT, if you
are feeling fantastic then that is the desired outcome. Do you have a recording SpO2 device ? - that would be your
best guide as to if the machine you have is doing an effective job.

Cheers

DSM

[Maryland_Mike]

My first sleep study showed 144 minutes of sleep (I'm surprised there was that much sleep) with sleep efficiency of 80%.

There were a total of 87 respiratory events, with 11 central apneas, 0 obstructive apneas, 76 hypopneas and 0 mixed events. The report read: "The study revealed the patient did have severe obstructive apnea." I was confused by this as the only apneas I had were centrals.

Other data from the study: AHI was 36. Oxyhemoglobin desaturations down to a nadir of 88%. Mean oxygen saturation 94% during non-REM sleep.

My titration was on a Respironics machine controlled remotely. The prescribed pressure was 9 and for CPAP.

My AHI at titration was 1.2. Still no obstructive apneas, but there were 2 centrals and 3 hypopneas.

I haven't been able to duplicate those results with my S8, although, as I said, I feel great.

[twokatmew]

If you feel great, I wouldn't worry too much then. My diagnostic study recorded 1 central apnea, no obstructive apneas, and enough hypopneas to diagnose me with moderate obstructive apnea. Even if we have no obstructive apneas, we get a diagnosis of OSA as long as we have enough hypopneas. Hypopneas can be just as dangerous as obstructive apneas. My titration study recorded 11 centrals, no obstructive apneas and 5 hypopneas.

As my AHI is mid-teens and I'm not feeling well, my doc prescribed a two-week BiPAP trial for me to see if I do any better on BiPAP. Minor improvement so far. But ... when I asked my doc about centrals, he said I didn't have enough to worry about and that they often go away as we acclimate to xPAP.

[cpapquuen1]

My first sleep study showed 144 minutes of sleep (I'm surprised there was that much sleep) with sleep efficiency of 80%.

There were a total of 87 respiratory events, with 11 central apneas, 0 obstructive apneas, 76 hypopneas and 0 mixed events. The report read: "The study revealed the patient did have severe obstructive apnea." I was confused by this as the only apneas I had were centrals.

Other data from the study: AHI was 36. Oxyhemoglobin desaturations down to a nadir of 88%. Mean oxygen saturation 94% during non-REM sleep.

My titration was on a Respironics machine controlled remotely. The prescribed pressure was 9 and for CPAP.

My AHI at titration was 1.2. Still no obstructive apneas, but there were 2 centrals and 3 hypopneas.

I haven't been able to duplicate those results with my S8, although, as I said, I feel great.

With these numbers on your PSG, you need to be on one of the SV units. Of you feel good now, you will feel great on an SV unit.