Question for any respiratory experts - pressure centrals

dsm · Post by **dsm** » Tue Feb 14, 2006 4:38 pm

I am seeking clarification on what a 'pressure induced central' means.

I am interpreting this as the condition that may arise when someone is on an xPAP machine and their breathing slows/stops, in this instance, due to reacting to the pressure coming into their respiratory system from the xPAP machine.

I have noticed that the ISENS ESENS & RISE settings will vary the amount of pressure 'push' I can feel when transitioning from IPAP to EPAP. It seems to me that that pressure push if not adjusted right, could cause 'pressure induced centrals' in someone prone to them.

The above all seem to then vary noticably depending on the type of mask - especially the differences between nasal pillows vs standard nasal or f/f masks. Also different types of machines vary this effect yet again.

Thanks

DSM

WAFlowers · Post by **WAFlowers** » Wed Feb 15, 2006 8:51 am

This sounds like the problem I have. At 6 my apneas go away; at 8 my hypopneas are gone; at 9 my snores are a thing of the past; and at 10 I start throwing central apneas.

It is almost as if I'm hyperventilating and then don't have to breathe for a while.

NightHawkeye · Post by **NightHawkeye** » Wed Feb 15, 2006 9:46 am

WAFlowers wrote:It is almost as if I'm hyperventilating and then don't have to breathe for a while.

From what I've read that's exactly what is happening, Bill. Respiration is largely based on CO2 levels. When you hyperventilate, you blow off your CO2 and then your body just quits breathing for a while to let the CO2 rise.

I've been concerned about centrals because on my first trip to an ER I was told I'd blown off all my CO2, so I've known for years that I'm susceptible to that sort of thing. I kinda think that hyperventilation is a common, perhaps even necessary, response to the high CO2 levels which result from obstructive apnea. I had to train myself to exhale very slowly after awakening from apnea events at night in order to keep from hyperventilating. (And no, I didn't know they were apnea events at the time, but I do now.)

Regards,
Bill

WAFlowers · Post by **WAFlowers** » Wed Feb 15, 2006 1:12 pm

NightHawkeye wrote:Respiration is largely based on CO2 levels. When you hyperventilate, you blow off your CO2 and then your body just quits breathing for a while to let the CO2 rise.

Yes, I'm very familiar with the mechanics of hyperventilation and the problems it causes both from extensive scuba training and decades of dive experience as well as from First Responder training including oxygen therapy instruction.

However, it is good to get confirmation that this is essentially the mechansim at work.

dsm · Post by **dsm** » Wed Feb 15, 2006 1:59 pm

Interestingly my ever observant wife has recently been saying to me that she wakes to hear me (middle of night) panting. She has raised this several times in the past few weeks.

I had not known what to make of it. Unfortunately I can't get the data of the PB330.

I may switch back to a RemStar Auto for a while.

Also I am now trying nasal pillows masks. Am getting used to them - the one I have now (unbranded) feels great. I am not sure if they will change the panting breathing episodes which to date have been occuring whilst using f/f mask & PB330 at 15/8 cms

DSM

wading thru the muck! · Post by **wading thru the muck!** » Wed Feb 15, 2006 1:59 pm

WAFlowers wrote:This sounds like the problem I have. At 6 my apneas go away; at 8 my hypopneas are gone; at 9 my snores are a thing of the past; and at 10 I start throwing central apneas.

It is almost as if I'm hyperventilating and then don't have to breathe for a while.

If you don't "have to" breathe is this really a Central Apnea? And even if it is, it may not be a concern if it does not cause O2 desaturation below normal levels.

WAFlowers · Post by **WAFlowers** » Wed Feb 15, 2006 3:44 pm

wading thru the muck! wrote:If you don't "have to" breathe is this really a Central Apnea? And even if it is, it may not be a concern if it does not cause O2 desaturation below normal levels.

And this points out the limitation of using only a (good) machine to monitor events; they essentially look at only one piece of data (our breathing) and have no way to monitor our O2 desat.

Any pause in breathing (that is long enough) could be falsely interpretted as a central, but for it to really be a central your O2 desaturation.

So do I really have central apnea events at higher pressures? I dunno, but I really don't want to find out (the hard way).

DSM-guest · Post by **DSM-guest** » Wed Feb 15, 2006 6:15 pm

Bill (nightHawkeye)

With you N-595 - did you get the software as well or are you extracting live data off the serial port ?

Am interested as to how you produced the night desat charts. I haven't got round yet to setting up my PO for a nights analysis. I am currently just doing spot checks.

Also which model of DS100A are you using. The new or the older ?

Thanks

DSM

NightHawkeye · Post by **NightHawkeye** » Wed Feb 15, 2006 7:00 pm

DSM,

I'm using the N-395 with Score software. What is a DS-100A? (The probe, maybe? Obviously, I have no idea whether it's the old or new version.)

Regards,
Bill

DSM-guest · Post by **DSM-guest** » Wed Feb 15, 2006 8:21 pm

The DS100A (Adult finger probe)

What color is the plug ?

There are 2 main versions - both work with most Nellcor models but the later has extra chip technology for more stable readings and is complemented by extra circuitry in the Nellcor - the N595 has this feature 'oximax' - see oximax sensors ...

http://www.mallinckrodt.com/respiratory ... %20Eng.pdf

Cheers

DSM

DSM-guest · Post by **DSM-guest** » Wed Feb 15, 2006 8:32 pm

Bill,
Was the software expensive ? pls PM me if you don't want to post pricing.

Tks

DSM