Resscan Image

[jlhog]

Hello,
I am fairly new to all this. Just started therapy 12/30/11. Tuesday night I had some high numbers as shown in this graph. Is this a lot of central or nothing to worry about? This was not a normal night, but it dont look good to me..

[Pugsy]

Do you think that it is possible during that last really ugly cluster of events that you were perhaps awake a good bit of time time? What does a normal night look like?

[jlhog]

Pugsy, Is this a full time job for you. LOL. I do not remember being awake that last hour, but maybe. How does that effect the chart? Here is last nights for a comparrision.

[Pugsy]

It is bitterly cold with the wind and yucky today. I don't have anything else to do except play around here on the forum today. Tomorrow I have to be gone but today..I am stuck at home.

When you do your images..could you perhaps include the time frame? You are doing too good of a job cropping your images. Makes it hard to know the relation of the events to time frame involved.
Also...could you include your AHI and the breakdown in to event categories?

These machines don't know if we are awake or not. They will go merrily along scoring events even if you are awake and it really messes with how we interpret the data. It is quite common for centrals to be scored while awake. We simply don't breathe as smoothly and often hold our breath for periods of time and don't realize it when awake. It is not unusual to have a truckload of either event show up if you happen to be awake. I see it often the last hour or so of sleep if I lay there and toss and turn and think about getting up but don't. I ignore those because I know I was awake or semi awake.

Did you have any history of centrals during either one of your sleep studies? Original sleep study or the titration part of the sleep study?

Any coughing or a lot of tossing or turning during your time on the machine? Frequent mini awakenings?

I would toss out that one ugly night because it is obviously not likely going to be a typical night for you and concentrate on basing your therapy on last night if that seems to be more your norm. Stuff happens sometimes that we can't explain... your Tuesday night may just fall into that category.

[jlhog]

OK, I will include more info next time. I have never used that snipping tool until that first image I put up. It works pretty good. For now I will ignore Tuesday night and see if that happens again. You are a world of help to us new guys here. Thank you,,,,,

[DoriC]

I believe the red lines are scored as apneas and the black lines are centrals, yellow are unknowns.

[squid13]

Red is obstructive, black or dark purple is central or clear airway. Black squares on bottom are hypenoas.

[Lizistired]

If you can post, EVENTS, FLOW, MINUTE VENTILATION, FLOW LIMITATIONS, and LEAKS. PRESSURE if on auto, and SNORE if it shows alot. The last 2 just take up space if they don't show anything.
If you are not getting the FLOW data, watch the tutorial linked in my signature for that and other good info.

[Grand-PAP]

It is quite common for centrals (emphasis added) to be scored while awake. We simply don't breathe as smoothly and often hold our breath for periods of time and don't realize it when awake.

Hi Pugsy,

With the caveat that CPAP machine “can’t” recognize central apneas and with the understanding of differences of opinions regarding transitional sleeping issues, etc., for this post, I’ll just call CAs - “clear airway” events.

I’m new and even with therapy I am having CAs. For 50 nights of therapy my numbers are:

AHI: 8.0
OA: 1.2
CA: 6.3
HI: 0.3

So I’m trying to get a better understanding. A LOT of that understanding comes from frequent/experienced posters such as you. Your/their knowledge, experience and willingness to share that information are greatly appreciated.

That said, your above quoted comment add a wrinkle to my understanding.

A few weeks ago, as a test, I used a back-up CPAP only machine and deliberately held my breath – after exhalation – for 30 seconds. The machine scored all five as OAs. That seemed to make sense to me. I only had the pressure set at 10cm, but even at 20cm, with me “holding” my breath the machine would NOT have been able to “force” air down my airway. So, wouldn’t the airway “appear” to be obstructed?

Wouldn’t /shouldn’t they have been scored as OAs and NOT as CAs?

[Pugsy]

A few weeks ago, as a test, I used a back-up CPAP only machine and deliberately held my breath – after exhalation – for 30 seconds. The machine scored all five as OAs. That seemed to make sense to me. I only had the pressure set at 10cm, but even at 20cm, with me “holding” my breath the machine would NOT have been able to “force” air down my airway. So, wouldn’t the airway “appear” to be obstructed?

Wouldn’t /shouldn’t they have been scored as OAs and NOT as CAs?

Some people have reported holding their breath and "fooling" the machine and get an OA flag instead of CA. Here's what we are told about how the CA's are scored given the only thing the machine records and not EEG or thoracic effort or desat. When a cessation of air movement occurs the machines send out little test puffs of air to help determine the status of the airway.. is it open or closed. I get the impression that the machine looks for an echo of sorts to that little puff of air. In the Respironics machines these are pressure pulses.. In ResMed machines they call it FOT. Some rare people are so sensitive to these little probes that it bugs them....most never know they are happening.

Also remember..just because you are holding your breath doesn't mean your airway is blocked. It's a mechanical thing versus a collapse of tissue thing. It wouldn't be hard to give you mouth to mouth resuscitation and force some air down the airway.

Given all these little quirks.. the machine does a really decent job considering the limitations it deals with. In my mind if it is going to err.... it errs on scoring centrals when awake or semi awake or sleep onset.... when we know they wouldn't be scored in an in lab sleep study. I would rather it be over aggressive than under aggressive. I would rather go to my doctor with reports showing elevated centrals and have him reassure me that all is fine and these are normal "centrals" than to have machine go merrily along and not score any and maybe lull me into a false sense of security and have no clue that something weird is going on.

When you are awake and trying to fool the machine...you can't really expect any sort of consistency in regards to reporting which is what. There is more involved with these algorithms then just one single factor...it measures baselines and considers changes from that baseline and a whole lot more than we think about. Given the irregularity of awake breathing compared to sleep...the machine is easily fooled while awake. I don't know all the ins and outs of the algorithm but I know that a lot more goes on than one simple sensor that measures air flow. It is highly complicated.

[Grand-PAP]

Thanks Pugsy!

It's obvious that you and the machine are a lot smarter that I am. But, I'm learning!