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Resmed s9 and central apneas

PostPosted: Mon Mar 22, 2010 3:54 pm
by fre
As a established Cpap user, (11cm fixed pressure), the s9 is now apparently able to cope with my mixed central and obstructive events. Last night (the first with the s9), felt good and the machine is incredibly quiet, and felt like it is hardly doing anything, but with an AHI of 4.5 that seems pretty good. I am wondering if the AHI as reported on the screen is the number of events an hour the machine could not prevent or the total of those that happened.
The central apneas are from the instability of my sleep where the periodic limb movements arouse me and I hyperventilate resulting in blowing off the carbon dioxide and then the apnea comes as I stop needing to breathe until the carbon dioxide builds up again. As augmentation of the limb movements in the day has to be balanced with better slow wave sleep at night does any one have experience in using the data from the s9 to calibrate drug " holidays" for the dopamine re-uptake inhibiters ( Sifrol ).
thanks,

Re: Resmed s9 and central apneas

PostPosted: Mon Mar 22, 2010 8:42 pm
by AirBreather
fre wrote:I am wondering if the AHI as reported on the screen is the number of events an hour the machine could not prevent or the total of those that happened.

I have a ResMed S8, rather than an S9. However, I am sure that AHI events reported by the S9 are the number that the machine could not prevent and also the number that actually occurred, which are both exactly the same thing.

You probably meant to ask instead whether the reported number of events is the number the machine could not prevent or the number that would have occurred without therapy. If that is what you want to know, the answer is that the machine reports the number that were not prevented. It has no way to determine the number that would have occurred without use of the machine.

Re: Resmed s9 and central apneas

PostPosted: Tue Mar 23, 2010 1:50 am
by dave21
AirBreather wrote:I have a ResMed S8, rather than an S9. However, I am sure that AHI events reported by the S9 are the number that the machine could not prevent and also the number that actually occurred, which are both exactly the same thing.

Yes you are correct in your assumption, both for the S8 and S9.

AirBreather wrote:If that is what you want to know, the answer is that the machine reports the number that were not prevented. It has no way to determine the number that would have occurred without use of the machine.

Agreed, there's no way for the machine to detect an Apnea that didn't happen because the machine was helping you. The only way to detect how many Apneas you would be having on average would to come off of the machine and go for a sleep study which I wouldn't recommend. Hopefully FRE was properly titrated before so should have the AHI prior to CPAP and now knows the AHI post CPAP.

Re: Resmed s9 and central apneas

PostPosted: Tue Mar 23, 2010 8:29 am
by JohnBFisher
fre wrote:... The central apneas are from the instability of my sleep where the periodic limb movements arouse me and I hyperventilate resulting in blowing off the carbon dioxide and then the apnea comes as I stop needing to breathe until the carbon dioxide builds up again. As augmentation of the limb movements in the day has to be balanced with better slow wave sleep at night does ...

Wow! I'm impressed. Either you have a good doctor or you've done good research on this. Either way, this is a very well reasonsed / observed situation. As you note, you need the deep sleep, so having the periodic limb movements under control helps this. When you arouse, it probably brings you to the sleep onset theshold and the instability of your breathing may be explained by that. During this state, hyperventilation, hypoventilation, central apneas, and even periodic breathing can occur. The following article might be of interest:

Ventilation is unstable during drowsiness before sleep onset
http://jap.physiology.org/cgi/reprint/99/5/2036

fre wrote:... any one have experience in using the data from the s9 to calibrate drug " holidays" for the dopamine re-uptake inhibiters ( Sifrol ). ...

The S9 does a GREAT job of capturing VERY detailed data, including showing probable central apneas. They might not be central, but there is a high probability that they are. Essentially, the S9 detects that the airway is open when the apnea occurs. So, it should allow you to monitor changes in your sleep during your "holidays".

Hope that helps.

Re: Resmed s9 and central apneas

PostPosted: Tue Mar 23, 2010 10:59 pm
by free
Thanks for the replies, i am now going to gather the data on nights on and off sifrol. love the s9 so far.
The knowledge has come from both a good doctor and then I look it all up and try to make sense of it all. I enjoy the knowledge gained and have achieved the best outcomes that way.

Re: Resmed s9 and central apneas

PostPosted: Wed Mar 24, 2010 9:10 am
by JohnBFisher
free wrote:... The knowledge has come from both a good doctor and then I look it all up and try to make sense of it all. I enjoy the knowledge gained and have achieved the best outcomes that way. ...

Perfect! That is EXACTLY how we should work together with our medical team. Ask, learn, research and apply! Good for you! It's a great example for all of us.