Pressure Induced Centrals

[kurtr]

For my last study I was told that as the pressure goes above 9 cm I begin to get pressure induced centrals. Lots of them. My prerssure to get rid of obstructives on my back is 11-12. How have others dealt with this?

Thanks very much,
Kurt

[Georgio]

I haven't, but it can happen. Someone here with knowledge in this area can help. Keep asking questions.

Georgio

[track]

stay off your back and set the pressure at 9. You can do a search that will tell you the way others on the forum stay off their backs too.

[dsm]

For my last study I was told that as the pressure goes above 9 cm I begin to get pressure induced centrals. Lots of them. My prerssure to get rid of obstructives on my back is 11-12. How have others dealt with this?

Thanks very much,
Kurt

Kurt,

Bilevel S type
Some types of Bilevel machines can handle centrals - as a general rule a bilevel with very good sensitivity and set with a smallish pressure gap (3 to 4 CMs) should work for most people. Your epap (exhale) pressure would be set to 9 & ipap (inhale) pressure either 12 or 13 depending on how it feels. The risetime (speed with which the pressure increases when going from epap to ipap), can be adjusted to smooth the process out.

Bilevel S/T type
If a straight Bilevel doesn't help then you need a timed one but these are usually much more expensive. The time facility allows setting a minimum breathing rate & if a central occurs (you drop below the min breaths per minute) the machine kicks in with the pressure change from epap to ipap.

#2 Just to clarify ...
Pressure induced centrals are different from 'natural' centrals where by natural I mean the disorder where the sleeper just stops breathing unrelated to cpap pressure (and not including Cheynes-Stokes centrals). The reason I mentioned using a S type Bilevel is that if the condition is just due to the constant pressure from a cpap or auto, then an S type bilevel applying fluctuating pressure could well be what is needed to solve the problem, but, if it doesn't then the next step is the much more expensive S/T type bilevel where a 'backup' rate (called a BPM set at, for example, 12 breaths per minute) can get set & if the user drops their breathing rate lower than the backup rate setting (12 bpm in our example), the machine triggers a switch of pressures in the expectation it will start the user breathing normally again.

Good luck

DSM

[jnk]

A few pressure-induced centrals during titration or while getting used to treatment is no biggie. But when the mixed events and central events persist, a person may get diagnosed as having "complex sleep apnea."

You may want to check out this page and the links on it, if you want to begin researching it:

http://www.resmed.com/en-au/clinicians/ ... apnea.html

The article at the following link may be a good one to print out, if your doc isn't as familiar with complex sleep apnea as he/she should be:

http://www.sleepreviewmag.com/issues/ar ... -06_03.asp

Here is a description of what one interesting machine, the Adapt SV by ResMed, does to treat people diagnosed with complex sleep apnea:

"When patient tidal volume increases, the device IPAP decreases. When patient tidal volume decreases, the device IPAP increases. Thus the marked fluctuations in patient tidal volume that characterize complex sleep apnea are attenuated and usually the tidal volume is stabilized by the device. A longer-term correction is effected by the trailing 3-minute memory of minute ventilation and pattern of breathing. After a 3-minute initial collection period, the Adapt SV then sets a minute-ventilation target that is 90% of the previous minute volume. Hence there is a weak downward force on total minute ventilation that nudges the PCO2 upward 2 or 3 millimeters of mercury, decreasing or eliminating the frequent CO2 dips below the apnea threshold that drives the central events. . . . In the background lurks a subtle backup rate that is actuated only when needed. This feature might be considered similar to the synchronized IMV feature of a hospital ventilator."-- http://www.resmed.com/en-us/dealers/med ... daptSV.pdf

[kurtr]

Thanks for the advise and information.
I appreciate it very much.

Kurt

[dsm]

A few pressure-induced centrals during titration or while getting used to treatment is no biggie. But when the mixed events and central events persist, a person may get diagnosed as having "complex sleep apnea."

You may want to check out this page and the links on it, if you want to begin researching it:

http://www.resmed.com/en-au/clinicians/ ... apnea.html

The article at the following link may be a good one to print out, if your doc isn't as familiar with complex sleep apnea as he/she should be:

http://www.sleepreviewmag.com/issues/ar ... -06_03.asp

Here is a description of what one interesting machine, the Adapt SV by ResMed, does to treat people diagnosed with complex sleep apnea:

"When patient tidal volume increases, the device IPAP decreases. When patient tidal volume decreases, the device IPAP increases. Thus the marked fluctuations in patient tidal volume that characterize complex sleep apnea are attenuated and usually the tidal volume is stabilized by the device. A longer-term correction is effected by the trailing 3-minute memory of minute ventilation and pattern of breathing. After a 3-minute initial collection period, the Adapt SV then sets a minute-ventilation target that is 90% of the previous minute volume. Hence there is a weak downward force on total minute ventilation that nudges the PCO2 upward 2 or 3 millimeters of mercury, decreasing or eliminating the frequent CO2 dips below the apnea threshold that drives the central events. . . . In the background lurks a subtle backup rate that is actuated only when needed. This feature might be considered similar to the synchronized IMV feature of a hospital ventilator."-- http://www.resmed.com/en-us/dealers/med ... daptSV.pdf

JNK

That Resmed info is a good find - hadn't come across it before.

I find I have a love/hate (sort of) relationship with my Vpap Adapt SV - the machine certainly works for me but after repeated cycles of using it (say 2-4 weeks) then swapping to the Bipap AutoSV, I am intrigued by the difference between them.

This summarizes my reactions

1) Vpap Adapt SV 'irritates me' in that I don't seem to sleep as deeply or as consistently with it BUT, the days are generally pretty good ?
2) Bipap AutoSV is much gentler, I get nice deep & consistent sleep, BUT, days aren't always as good as with Vpap Adapt SV ?

Above is after 12 months of swapping between the two. Last night I reverted back to the Bipap AutoSV as I was getting 'irritated' again by the Vpap Adapt SV

I just can't make real sense of why this pattern keeps occurring & seems entirely predictable. One clue seems to be (Vpap Adapt SV) the mention of controlling PCO2 by regulating IPAP as described in the item posted. I have long suspected that the Vpap Adapt SV controls CO2 better & that despite the irritation I feel with it, it is delivering a better result.

But, I do like going back to the Bipap AutoSV for the feeling of a good nights sleep - strangely, I am less likely to want to get up early after a night with the Bipap AutoSV whereas with the Adapt SV I almost always start clock watching 30 mins or so before getting up (alarm is set for 5:40 am).

DSM

DSM

[jnk]

. . .
1) Vpap Adapt SV 'irritates me' in that I don't seem to sleep as deeply or as consistently with it BUT, the days are generally pretty good ?
2) Bipap AutoSV is much gentler, I get nice deep & consistent sleep, BUT, days aren't always as good as with Vpap Adapt SV ?

Above is after 12 months of swapping between the two. Last night I reverted back to the Bipap AutoSV as I was getting 'irritated' again by the Vpap Adapt SV

I just can't make real sense of why this pattern keeps occurring & seems entirely predictable. . . . .

My guess is that I would probably find either/both machine(s) irritating with a negative effect on my overall sleep, since I don't think I have complex sleep apnea or any significant disordered-breathing pattern beyond simple obstructive sleep apnea. (Yet, anyway. ) And switching between the two would probably be enough to confuse the heck out of my poor brain!

[dsm]

. . .
1) Vpap Adapt SV 'irritates me' in that I don't seem to sleep as deeply or as consistently with it BUT, the days are generally pretty good ?
2) Bipap AutoSV is much gentler, I get nice deep & consistent sleep, BUT, days aren't always as good as with Vpap Adapt SV ?

Above is after 12 months of swapping between the two. Last night I reverted back to the Bipap AutoSV as I was getting 'irritated' again by the Vpap Adapt SV

I just can't make real sense of why this pattern keeps occurring & seems entirely predictable. . . . .

My guess is that I would probably find either/both machine(s) irritating with a negative effect on my overall sleep, since I don't think I have complex sleep apnea or any significant disordered-breathing pattern beyond simple obstructive sleep apnea. (Yet, anyway. ) And switching between the two would probably be enough to confuse the heck out of my poor brain!

Guess is being generous

D