Question about Centrals and advice.

[SayHelloForMe]

I have been having six to seven centrals every night on my Resmed s9 Autoset. I only have one obstructive every 2 to 3 days. I understand that sleepyhead calls them Open airways but the Resmed Program calls them "Centrals." Looking at the software, I flat line for 15 to 20 sec each time it flags it as a central. I still feel tired in the morning. My question is what is a normal number of centrals that are acceptable ? Should I consider turning my pressure down ? Am I that person that has now developed centrals from cpap ? Any advice is much appreciated for this sleepy head !!

[Todzo]

I have been having six to seven centrals every night on my Resmed s9 Autoset. I only have one obstructive every 2 to 3 days. I understand that sleepyhead calls them Open airways but the Resmed Program calls them "Centrals." Looking at the software, I flat line for 15 to 20 sec each time it flags it as a central. I still feel tired in the morning. My question is what is a normal number of centrals that are acceptable ? Should I consider turning my pressure down ? Am I that person that has now developed centrals from cpap ? Any advice is much appreciated for this sleepy head !!

do you mean six to seven "centrals" per hour?

If I stop breathing for 20 seconds I will not feel a great deal of air hunger. Those into eucapnic breathing strive to reach a point where that is true for 40 seconds. If all your systems are well fed and you are not using a lot of energy there is not a great deal of the need to breath. If your pour coffee, or work on something that requires a great deal of skill you are likely to stop breathing for a time. If you roll over in bed you may stop for a time. Pauses in breathing are natural and I am not sure that the algorithm which checks your flow data (they have no abdominal belt to check for respiratory effort after all) for pauses is smart enough to check your air use before and after the event to even use that to help see if the pause is likely a true "central apnea" much less determine if it is a hypercapnic or a hypocapnic central apnea.

Eight pauses in a night (one per hour) not to worry I think. Five an hour is something to look into a bit.

I tend to modify lifestyle and check other health things before looking at pressure changes.

Breathing control is helped by proper vitamin D3 levels. Above 50 ng/ml. See The Vitamin D Council for assay details.

I believe it is also helped by moving toward an active lifestyle. I recommend pursuing 10,000 steps a day (slowly but surely) and working with a personal trainer.

I believe that health in general is what we need to pursue. So to round out what is needed for good metabolic health I recommend using a dietitian for several years.

[avi123]

Resmed gives these about having too many centrals. But we can't use our home machines to check it accurately b/c we don't have the abdomen and chest straps sensors. We can't tell if an hypopnea is obstructive or central :


http://www.resmed.com/us/en/commercial- ... g-csr.html





The probability of having Cheyne Stokes Respiration (CSR) existing, is reported if the sleep study shows:

A•At least 3 consecutive cycles of a cyclical crescendo and decrescendo change in breathing amplitude; cycle length is most commonly approximately 60 seconds, although the length may vary.

B•One or both of the following:

......... ◦5 or more central sleep apneas and/or {central} hypopneas per hour of sleep.
{you take your total hours of sleep and divide it by the total number of Central events}
......... ◦At least 10 consecutive minutes of the cyclic crescendo and decrescendo change in breathing amplitude.

I think that you need to have A and B to show a CSR problem.

For Complex Sleep Apnea you also need to show 5 or more central events per hour for how long?
Check this about it:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2576323/

p.s. it has nothing to do about food.

[Todzo]

Am I that person that has now developed centrals from cpap ?

So CPAP was developed in 1981. Finally in 2006 they notice that it induces central apnea.

Why so long to notice? Reductionist thinking. They look too narrow and so miss a lot!!!

All have more of a tendency to have hypocapnic central apnea from CPAP. Some will, some will not – on any given night.

If you are healthy your tendency to have a central apnea induced by CPAP will be less. It simply will will be.

But the reductionist thinker will miss the link for sure.

[Country4ever]

I don't know that much..........but I was wondering just today about CAs. Are they just the body's attempt to stabilize the pH? What I mean is, perhaps our CO2 gets too low with the use of cpap and it's just stopping breathing for a little while, to raise the CO2? Does anyone have an oximeter in sync with their cpap? Just wondering what it does during the CA........or would that not really show much?
When you have a CA........is your respiratory rate fast just before that, or maybe you take very large breaths right before that? For some, a CA is a problem with the brain........but for many of us, I'm just wondering if they show up for a good reason.

[Todzo]

I don't know that much..........but I was wondering just today about CAs. Are they just the body's attempt to stabilize the pH? What I mean is, perhaps our CO2 gets too low with the use of cpap and it's just stopping breathing for a little while, to raise the CO2? Does anyone have an oximeter in sync with their cpap? Just wondering what it does during the CA........or would that not really show much?
When you have a CA........is your respiratory rate fast just before that, or maybe you take very large breaths right before that? For some, a CA is a problem with the brain........but for many of us, I'm just wondering if they show up for a good reason.

So it is time to adjust the shower heat. You turn the knob the normal amount but – hot hot. You turn it down the amount you think should compensate – cold cold. Your roommate turned up the thermostat on the water heater.

The pressure of CPAP simply turns up the “gain” (heat) of the respiratory control system. If it is already too high for other reasons things may get out of hand. If it is very healthy it may keep things in hand.

There is a common thread I see represented here and have experienced myself. You wake up breathing heavily and just “can't seem to get enough air” - but if you look at the situation it makes no sense. You are at rest and in bed for goodness' sake. When this happens, consistently, using eucapnic breathing techniques does quench the crazy air hunger within two minutes for me every time.

I have seen no good explanation for the crazy air hunger from anywhere. I have experianced that it seem to be related to my general life stress levels. I wonder if it may have to do with the fact that circulation tends to be cut off by the vasoconstriction induced by hypocapnea. Since the central and peripheral chemoreflex sensors would be unusually separated by this perhaps it throws the system into a mode where the attempts of the system (heavy breathing) to correct high PH in the area of the central chemoreceptors is met by the vasoconstriction experienced in the circulatory system so the time to receive the message (PH adjusted blood) is extended perhaps indefinitely.

[robysue]

I have been having six to seven centrals every night on my Resmed s9 Autoset. I only have one obstructive every 2 to 3 days.

Six or seven events per NIGHT of any type is quite acceptable in terms of overall efficacy of therapy. The goal of PAP is to keep the total AHI below 5---i.e. have a average of less than five events per hour. If you are using the machine for a typical 6-8 hours, that's an average of about one CA per hour, and your OAI is negligible. To put the number of your events in perspective: If you sleep for 7 hours and the AHI is 4.0, you'll have a total of 28 events over the course of the night.

I understand that sleepyhead calls them Open airways but the Resmed Program calls them "Centrals." Looking at the software, I flat line for 15 to 20 sec each time it flags it as a central.

I'm a bit confused here: Sleeyhead calls centrals CAs (clear airway apneas) and it calls obstructive apneas OAs. Is it possible you have six to seven OAs per night and are seeing a CA every 2 or 3 days?

I still feel tired in the morning. My question is what is a normal number of centrals that are acceptable ?

There are a whole lot of things that affect the quality of our sleep beyond sleep apnea. If your overall AHI is well below 5.0, your longest events are less than 20 seconds long, and you don't have any really large clusters of events, then chances are undertreated sleep apnea is probably not the issue.

If you are a new PAPer, it could just be you need more time for your body to heal from the years of untreated OSA. Most new PAPers don't really feel much different in terms of tiredness and daytime sleepiness until they've been using the machine for several weeks to a couple of months. Some new PAPers take a lot longer than that to feel much better. And a few unlucky PAPers never feel much of a difference in terms of daytime fatigue or sleepiness---possibly because the damage the untreated OSA did to their body is just too much to heal completely.

It could also be that you've got something else going on with your sleep: How much sleep do you think you get each night? How restless are you when you are in bed? How long does it take to fall asleep? How many times do you think you wake up at night?

And it could also be that you've got something else going on medically: When's the last time you had a full physical exam? Have the usual suspects of low thyroid and low vitamin D been checked out? Any chance you're clinically depressed? All those things are known to cause problems with fatigue. If you are taking any medications, it's possible the fatigue is an unwelcome side affect. So when's the last time you and the prescribing doc talked about the side affects of the meds you are taking?

Should I consider turning my pressure down ? Am I that person that has now developed centrals from cpap ? Any advice is much appreciated for this sleepy head !!

1) I would NOT turn the pressure down just because of a small number of centrals. The prescribed pressure is what is needed to prevent the vast majority of obstructive events from happening and turning it down can allow a whole bunch of obstructive events to occur. That said, many people are slightly over titrated and can reduce the pressure by 1 or 2 cm without a huge increase in the number of obstructive events. In your case you might find that reducing the pressure by 1 or 2 cm eliminates the centrals, but allows six or seven OAs or Hs to happen every night. In other words, your total AHI might not go down even if you do eliminate the centrals.

2) Some centrals are normal: The transition to sleep is not smooth and in some people, there's a tendency to have a few "central apneas" during the transition to sleep. These sleep transition apneas are not even scored on an in-lab sleep test unless they're so numerous as to make the transition to sleep very, very difficult. And your S9 cannot tell when you are asleep or when you are awake or when you are transitioning to sleep. Hence it can score "centrals" that are not real in the sense of meeting the criteria for scoring a central on an in-lab sleep test.

3) Wake breathing can confuse the machine and lead it to score "central apneas" that are not real. Wake breathing is much more ragged than sleep breathing, even though we're not totally aware of this fact. We sigh, we take a deep cleansing breath, we hold our breath for a few seconds when concentrating on something---something as simple as turning over in bed. And again, your S9 cannot tell when you are asleep or when you are awake or when you are transitioning to sleep. Hence it can score "centrals" that are not real in the sense of meeting the criteria for scoring a central on an in-lab sleep test. So it's worth looking at the times those machine scored CAs are occurring. If you are restless or awake during these times, it's reasonable to conclude that some or all of the CAs are not real sleep disordered breathing events.

4) If you are reporting the number of your events correctly when you say you have six or seven CAs per NIGHT correctly, then you do NOT appear to meet the diagnostic criteria for Complex Sleep Apnea. CompSA is the name for the condition of developing central sleep apnea problems after starting CPAP for treating OSA. The diagnostic criteria for CompSA are ALL of the following:

• A diagnostic test for OSA that shows no problem with CAs before CPAP is started to treat the OSA
• And after CPAP is initiated:
  • A residual AHI > 5.0. (The residual AHI is the (long term) AHI when using CPAP to treat the OSA---i.e. the AHI your S9 reports is a good approximation of the residual AHI.)
  • At least 50% of the residual events are CAs. (In other words, at least half the events scored by the CPAP machine are CAs.)
  • And a CAI > 5.0 when on CPAP. (In other words, you have to have an average of at least 5 CAs per hour every night.)

That said, if you are really worried about this, you should speak to your sleep doctor about it and show him/her the data from your machine. To diagnose CompSA will likely require another in-lab sleep test so that the real sleep disordered central apneas can be accurately distinguished from the normal "central apneas" of sleep transition and wake breathing.

[SayHelloForMe]

Thanks for all the input. I am having 7 to 8 per NIGHT so it seems nothing to be concerned about. As far as my health goes, I had a complete physical 7 months ago and everything was fantastic. I do exercise every day walking over 5 miles a day. I am not overweight and eat mostly Vegetables, fruits, beans and nuts ( Vegen )

I sleep for about 7 to 7.5 hrs a night and seldom weak up. I do not take any type of medication. I do not drink nor smoke.
My AHI is 0.6 on average. So I guess it is nothing to worry about.

Someone asked about an Spo2 meter. Well, I have one and use it from time to time and I did NOT noticed a desat of O2 after any of my centrals. Mine never dropped below 93% all night. I did not think about looking to see it the o2 went up and then a central occurred.Interesting. I wonder how many centrals a normal person experiences that does not have sleep apnea ? Does everyone have them ?
Even if they had 10 events per NIGHT, they would not be considered to have sleep apnea because AHI would be below 5.


I have been a little stressed lately and maybe I am waking up more than I think I am,making me tired during the day.
How many of you with a Resmed S9 Autoset NEVER sees a central ? But then again, it could be a pressure difference.

[Pugsy]

Not all centrals (assuming they are real centrals and not some sort of artifact) are related to pressure.
Yes, some people will see centrals that come on in large numbers related to cpap pressure therapy but it can happen just as easily with a pressure of 6 or 7 cm.

Reducing the pressure only reduces the centrals IF they are caused by the pressure.
Usually if they are caused by the pressure they present themselves in large clusters and cluster often during the night and happen pretty much every night.

7 or 8 centrals per night isn't a big deal even if every single one of them were "real".

The % of people who develop CompSA because of cpap pressure is really quite small and they have a whole lot more centrals per night than 10 to even 30...and it happens almost every night and not now and then.

Generally for centrals to be considered bad enough to consider doing something about we need to see a central index of at least 5 per hour...and have it be present on most nights. Not just a random night here and there.

[SayHelloForMe]

Pugsy , My centrals happen every night. My obstructive only happens every now and then. My prescribed pressure was 7 in the sleep lab. Back then I had an S8 Auto and it wanted to go up to around 12. I thought, could the sleep lab be this wrong ? After juicing and exercise , I lost 15 pounds and my pressure went down to 10.5 on the S9 auto. My thoughts are from 7 ( in the lab ) to a 12( my old S8) is a tremendous jump. Could the sleep lab be wrong or maybe my machine? I could understand if the number difference was only by 2 but not by 5cmH20. I don't think having 7 centrals EVERY night is "normal" and true, its not bad because the total AHI is way below 5.So maybe this is really nothing to worry about ? I just wonder if I could eliminate then if I was on a BI pap. I just don't want to stop breathing one night and not wake up the next day ( even though dieing in your sleep is probably the best way to go

My EPR was at 3 so I turned it OFF and NO change at all and its been over 2 weeks.

There is no way to tell if they really are centrals except to go back to the sleep lab but it is the "best guess" from the S9 Autoset.

[Pugsy]

Could the sleep lab be wrong or maybe my machine?

In terms of pressure needs..absolutely they could be wrong. Do you think you sleep the same way every night much less in a foreign environment?

I don't think having 7 centrals EVERY night is "normal" and true, its not bad because the total AHI is way below 5.So maybe this is really nothing to worry about ?

Then you need to talk to your doctor about your concerns. You are fixated and worrying about centrals that may or may not be "real" centrals in terms of what a doctor would worry about.
If you aren't comfortable with 7 (assuming they were all real which maybe they were but most likely some were false positives) centrals during the night is not a problem....then talk to your doctor.

I repeat...not all of those 7 centrals that happen during an 8 hour period are with absolute certainty a real central that would be considered worrisome anyway.
The machine can and will flag awake breathing by mistake. I personally have seen it...once when I was sick to my stomach and I had about 22 centrals during about 45 minutes and I know with absolute certainty that I was fully awake.

If your "centrals" are false positives from awake breathing or even a real sleep onset sleep stage transition...using bilevel pressure machine won't eliminate them..

Not all centrals are related to pressure...and if not related to pressure then going to bilevel is not likely to help.
Those 22 centrals I had when I was awake and sick during 45 minutes...that was last summer on a biPap machine...

[robysue]

Pugsy , My centrals happen every night. My obstructive only happens every now and then. My prescribed pressure was 7 in the sleep lab. Back then I had an S8 Auto and it wanted to go up to around 12. I thought, could the sleep lab be this wrong ? After juicing and exercise , I lost 15 pounds and my pressure went down to 10.5 on the S9 auto.

The old S8 did not try to distinguish between central and obstructive apneas. It may have been inappropriately increasing the pressure due to central apneas occurrring when the pressure was still below a certain threshold. The old S8 responded to all events below the threshold, but it did not respond to events above the threshold because of increasing probability that some or all the events might be centrals in some patients. I can't remember the exact threshold, but I believe it was around 10-12 cm.

My thoughts are from 7 ( in the lab ) to a 12( my old S8) is a tremendous jump. Could the sleep lab be wrong or maybe my machine? I could understand if the number difference was only by 2 but not by 5cmH20. I don't think having 7 centrals EVERY night is "normal" and true, its not bad because the total AHI is way below 5.So maybe this is really nothing to worry about ?

Seven centrals every night in a seven to eight hour time in bed window is NOT something to worry about. That's an average of no more than one per hour.

As for why the S9 wants to go significantly higher than the in-lab titration: Factors include the fact that we don't sleep the same every night, and the lab titration might have been a good night. But the S9 machine itself may be wrong here and raising the pressure more than you strictly need. And why would that happen? Here are two reasons:

• Misinterpreting normal wake sleep patterns as flow limitations or hypopneas and increasing pressure at a point when a sleep tech monitoring the EEG data would NOT increaase the pressure because the so-called "events" are NOT really sleep disordered breathing because you're awake when they happen. Note too: We seldom remember a wake that lasts less than 5 minutes and so it's possible that this can happen without you remembering it.
• Deciding you are snoring when you are not actually snoring, but the machine increases the pressure anyway. Some machines are particularly prone to picking up vibrations from other sources and deciding that they're coming from the user snoring. Things that can be misinterpreted as snoring under some circumstances include: the hose rubbing against a corner of the bedtable; a bed partner's snoring; or a pet's snoring.

Another source of discrepancy between the in-lab titration pressure level and the S9's 95% pressure level might due to the fact that many labs do NOT continue to titrate the pressure upward once the obstructive events go away. In other words, if no OAs or Hs are occurring, then the tech may very well NOT increase the pressure just because there is some (minor) flow limitation going on or very soft snoring going on. But the S9 will aggressively increase the pressure in the presence of even minor flow limitations and minor snoring.

And note that too much pressure can cause problems. To give you a specific example, my three BiPAP titrations have all come in indicating that I need rather low pressures to control my obstructive events with an IPAP = 8 and an EPAP = 4, 5, or 6 depending on the study. I usually run my BiPAP in Auto mode with max IPAP = 8 and min EPAP = 4; my 90% IPAP is usually 8.0 and my 90% EPAP usually is between 5.0 and 5.5. Once or twice a year I'll bump up that max IPAP setting for a few days, just to see what the machine "thinks" I need. When I do this, the 90% pressure levels often jump by two or three cm, but there is absolutely NO improvement in my overall AHI (which is typically below 2.5) and there's no real improvement in my FLI or my VSI index. In my case the machine usually responds way to aggressively to "snoring" that my hubby usually says did not exist and that bumps everything up. But more than the lack of improvement of numbers, what gets to me is that when the EPAP gets above 6.0 cm for any length of time or the IPAP gets above 10 cm for any length of time, my aerophagia comes back with a vengeance and that by itself is enough to cause a serious deterioration in the quality of my sleep and in how well I feel the next day.

I just wonder if I could eliminate then if I was on a BI pap. I just don't want to stop breathing one night and not wake up the next day ( even though dieing in your sleep is probably the best way to go

When I was switched from the S9 Autoset to the PR System One BiPAP because of severe aerophagia problems, my overall AHI didn't change much, but the distribution of events did. I have more centrals with the BiPAP than I had with the old S9 AutoSet and the AutoSet was using similar pressures: min pressure = 4, max pressure = 8.

My EPR was at 3 so I turned it OFF and NO change at all and its been over 2 weeks.

No change in AHI or no change in how you feel? Your AHI is already so low that there is no point in trying to eliminate the last few events. You need to focus on what makes you feel better during the day. If that's sleeping at slightly lower pressures than the S9 thinks you need then do that. If turning EPR on makes you feel better, then do that.

A lesson I had to learn the hard way: 'Tis better to get some high quality sleep with an AHI = 2.0 and feel good in the daytime than it is to get mediocre sleep with an AHI close to 0.0.

And a corollary lesson: The things we sometimes need to do to get a (near) perfect AHI = 0.0 can cause a significant amount of discomfort and lead to bad sleep. In other words, there's a point of diminishing returns when it comes to trying to eliminate the last few events, regardless of what kind they are. And I suspect you've reached that point.

There is no way to tell if they really are centrals except to go back to the sleep lab but it is the "best guess" from the S9 Autoset.

With less than 10 events per NIGHT, no doctor is going to be willing to send you back to the sleep lab just to find out if those six or seven "centrals" the S9 is scoring are real are not. Now, if you're not really feeling well in spite of using the CPAP for a long time or if you've got a serious problem with aerophagia, then maybe a sleep doc would be willing to send you back to the lab. But the point of the test would not be to figure out if the handful of residual events are OAs or CAs. The point of the test would be to see how many spontaneous arousals you are having while on PAP, whether you're now dealing with some PLMD, and whether the titrated pressure of 7cm is way off target.