Unusual ResScan Obstructive Pattern

[avi123]

Having had ResMed S9 Autoset flow curves similar to Bandnuts', I am really interested to see what his upcoming PSG night determines.
But not having had any cardio-vascular or cerebro-vascular problems dx'd before, I wonder about the above story:

- can a sleep doctor or sleep tech UNMISTAKABLY see Cheyne-Stokes patterns when provided just the ResMed flow curves? without SAO2% and EEG?
- are most multi-channel PSG studies set up with automatic software tests and sleep tech attention to "ring a bell" on Cheyne-Stokes, as Bill implies? (my PSG used REMbrand). WHAT ARE CHANCES THAT THESE PATTERNS ONLY APPEAR UNDER CERTAIN, YET UNCLARIFIED, SLEEP AND CPAP CIRCUMSTANCES?
In trying to differentiate Cheyne-Stokes from CPAP-induced centrals, those of you more familiar with the issue may care to check out the following article:
http://pats.atsjournals.org/cgi/content ... 2/226#FIG1
Central Sleep Apnea and Cheyne-Stokes Respiration D Yumino, TD Bradley
Proc American Thoracic Society 5:226-236 (2008)

Thanks for the link. It's quite theoretical.

May I try to answer your question by saying that almost all PSGs in the U. S. are done per standard guidelines from the Task Force of the American Academy of Sleep Medicine (AASM). They are not intended to be specific to analyzing Cheyne Stokes but should come up with more accurately results than we could do with CPAPs. More tests will be needed to analyze and monitor the disease. IMO, the emphasis will be more on medication than ventilation. The main tasks will be up to those physicians handling the case.

[NotMuffy]

...FOTs don't show up on OAs---that's exactly how the machine decides they are OAs instead of CA: The FOTs do NOT get through the obstruction and hence the air movement (flow) remains flat.

That assessment certainly has a great deal of logic to it, and while flow is reduced in an OA, it appears that it can have a FOT with a flow < ~0.035 +/- 0.005 LPS and still be an OA.

[NotMuffy]

Magnifying the FOTs shows the difference between an OA (left) and CA (right):

[JDS74]

That pattern is Cheyne-Stokes and patients suffering from atrial fibrulation frequently also have Cheyne-Stokes. If you doctor is not a cardiac specialist, ask for an immediate referral so that this information can be included in you cardiac treatment. No time to dawdle with this one.

You may need an ASV machine to help control this breathing pattern so that also needs to be part of the discussion.

Cheers

[avi123]

Magnifying the FOTs shows the difference between an OA (left) and CA (right):

What's the purpose of having the FOT in the S9 Elite which operates in CPAP mode only?

[NotMuffy]

What's the purpose of having the FOT in the S9 Elite which operates in CPAP mode only?

Knowing is better than not knowing?

[NotMuffy]

Using a different tool to try to quantify the flow rate diferences between OA and CA:

[billbolton]

are most multi-channel PSG studies set up with automatic software tests and sleep tech attention to "ring a bell" on Cheyne-Stokes, as Bill implies?

I did not imply that at all.

I did imply that there is an issue of adequate personal competance involved in being able to identifiy periodic sleep breathing issues, as distinct from aperiodic sleep breathing, from PSG data. You may choose to read into that whatever you wish.

Cheers,

Bill

[NotMuffy]

Pressure analysis of FOT. Same area, OA F/B CA. Note pressure increase from ~7.3 cmH2O to ~8.3 cmH2O after FOT identified the event as an OA. OA pressure profile just a smidge higher than CA profile: