Question about REM sleep and Centrals.

[Dolpp]

Just want to bounce this off some people and see if it makes any sense. My sleep doctor recently put me on a BiPaP machine at a setting of 12/8, despite the fact that there were a lot of centrals during my sleep study at that setting. But almost no o's or hyp's. I was going through my old sleep studies and noticed that this sleep study is the only sleep study that I had any substantial REM sleep (about 45 mins). Now since I went to this setting my software showed a lot of centrals (up in the 20/hr range) that made me nervous so I titrated myself to a different pressure. When I went through the sleep study I noticed that a majority of the centrals were during REM sleep. It got me thinking........I have an extremely low resting heart rate, between 39-42 during all of my sleep studies and 36 during a 24 hour holter monitor test. I've had an echo done and everything is normal. My heart is very efficient according to the tests therefore doesn't beat as often. Do you think that because of the low resting heart rate that maybe I don't breathe as often when i am completely at rest (during REM sleep especially) and these show up as centrals but are completely normal? I know some centrals are normal but 20/hr seems a little excessive, but maybe not?

[timbalionguy]

I am not a doctor, so take my thoughts/suggestions with that in mind.

You are lucky to have such a low heart rate. I am just the opposite-- my heart rate is quite a bith higher than normal. But CPAP, along with at least holding my weight reasonably constant (120 lbs overweight) has helped with this considerably.

Like you, I have had a history of erratic patterns of centrals that really seem to manifest themselves during sleep studies. It is of enough concern that I have been prescribed with (and finally hope to get today) An Auto SV machine. Bilevel therapy, when tried in the sleep lab, seemed to make this worse. In fact, bilevel therapy did very little for me. Unlike you though, most of my centrals are happening at sleep onset, which is more typical.

Do you have a pulse oximeter? I don't yet. If you are consistently showing that high rate of centrals during REM sleep, it would be very interesting to see what your blood oxygen is doing. If it is staying in the normal range, and you are otherwise not having arousals, I would at least keep an eye on it, and discuss it with your doctor on your next visit. If you are having desats, you are then likely to have pressure-induced central apneas, which is called Complex Sleep Apnea Syndrome, or CompSAS. It may be time for you to get on an Auto SV machine as well. These are designed to treat central apneas, periodic breathing, etc.

One thing I have seen mentioned here is that bilevel therapy is not always recommended for people who have central apnea or CompSAS. (Nor is autoadjusting therapy, although my doctor prescribed it in my particular case.) You might try experimentally lowering your IPAP, and see if that makes a difference. If you start to see OSA type apneas/hypopnas increase while trying this when trying this, try increasing your EPAP by 1 or 2 cm. Above all, do not rush this, and be gradual in your adjustments.

Good luck on working this through!

[Dolpp]

I don't have a pulse oximeter can anyone recommend a good one? Maybe that is something I should look into.

On my last sleep study during REM sleep my SaO2 was between 97-100 with a mean of 99.1. It was actually a little worse when I was awake. So maybe I shouldn't worry about those centrals that much, my doctor doesn't seemed to be concerned with them at all. But he doesn't take the software seriously and they are much worse then they were on my sleep study.

[Mary Z]

Does the readout on your machine show your RR? I'm no sleep professional, but what you suggest- a correlation between your resting heart rate and your RR might be the answer.
Mary Z.

[timbalionguy]

I don't have a pulse oximeter can anyone recommend a good one? Maybe that is something I should look into.

Can't help you with a recommendation there.

On my last sleep study during REM sleep my SaO2 was between 97-100 with a mean of 99.1. It was actually a little worse when I was awake. So maybe I shouldn't worry about those centrals that much, my doctor doesn't seemed to be concerned with them at all. But he doesn't take the software seriously and they are much worse then they were on my sleep study.

That's why you need to find this out for yourself, and see if that good blood oxygenation persists during REM sleep. If it does, then you might be experiencing a unusual kind of 'periodic breathing'. Periodic breathing where the body is trying to prevent being hyperventilated, and the CO2 level getting too low (Yes, there is supposed to be a certain level of CO2 in the blood to maintain a proper electrolyte balance). In most people, this is a fairly long cycle. In your case, with your slow heartbeat, it might be a fast enough cycle to be indistinguishable from a central apnea. If your O2 sat is indeed good, and you do not have any other underlying health issues, maybe this particular central apnea is not worrisome. But ultimately, only a good doctor can confirm that. Perhaps, you need a second opinion in this case.

[JohnBFisher]

I tend to agree with everyone that you should be checking your heart rate and O2 saturation with a pulse oximeter.

Timbalionguy, how goes your new setup? Remember, it will be REALLY strange to have the unit suddenly ramp up pressures. It takes time to adjust to that. But you will adjust and not notice all that much after a few months.

[Dolpp]

I did notice that on the nights the I was on the BiPaP at a pressure of 12/8 that I had a lot higher "percent of night in periodic breathing" I don't have the numbers in front of me but it was substantially higher than when I was at just a straight 8 CPAP. I'm not exactly sure what that means. Can somebody explain what periodic breathing means and how it pertains to my situation.

Also, Can anybody recommend a good pulse oximeter? I see there are a whole lot to choose from from very inexpensive to very expensive.

[JohnBFisher]

... I did notice that on the nights the I was on the BiPaP at a pressure of 12/8 that I had a lot higher "percent of night in periodic breathing" I don't have the numbers in front of me but it was substantially higher than when I was at just a straight 8 CPAP. I'm not exactly sure what that means. Can somebody explain what periodic breathing means and how it pertains to my situation.

Also, Can anybody recommend a good pulse oximeter? I see there are a whole lot to choose from from very inexpensive to very expensive. ...

Okay, please be aware that I am not a doctor, but have read extensively on central apnea (in the various forms).

You need to realize that periodic breathing can be an indication of heart problems. It could be that the increased pressure led to this pattern for you. Or it might indicate there is an underlying issue that needs to be addressed. This might be nothing at all, other than a slightly unusual response to the increased pressure.

You really should discuss this with your doctor. If your sleep doctor dismisses it, ask if he is certain there is not heart involvement. I would rather see you be screened for potential heart issues and find none, than the other way around.

Best wishes.

[Dolpp]

When I discovered the abnormally slow heart rate about a year and a half ago I had a 24 hour holter monitor test done and and echocardiogram done. The results were that my heart was a lot more efficient than most peoples (probably attributed to the fact that i have been a long distance runner for most of my life up until this apnea fatigue has made it difficult to run as much as I would like to). Do you really think I
need more testing done than that? I have also never seen any central apneas on any of my 4 sleep studies except for with the bipap and they didn't even start until a pressure of 12/8. Which is the pressure the doctor prescribed because that is when the other apneas went down to almost 0.

[timbalionguy]

Interesting. The fact that you are seeing these centrals and periodic breathing would tell me that there is something going on here, and it may not necessarily be heart-related. As has been mentioned previously, periodic breathing is generally a sign of CO2 dysregulation. And although things like congestive heart failure might be the most common csuse, there are other, usually CNS-related causes. I think John Fisher's situation is a classic case of CNS problems. It is also possible that what the relatively primitive algorithms in the machine are calling periodic breathing is actually something else. This can only be elucidated in a PSG.

In any case, you have a lot to talk about with your doctor.

[Dolpp]

Does anybody think that it could be just caused by the BiPap?
According to this study, http://www.pulmonaryreviews.com/dec05/bipap.html .They seem to say that BiPaP machines can cause central apneas, and it doesn't seem to be that rare. I believe it said in 24% of otherwise "normal" individuals.

[JohnBFisher]

I also tend to agree that just based on your history, it does not sound as if congestive heart failure is the option. More likely, it is possible that due to the better efficiency of your cardiovascular system your tend to be outside of the norm for breathing patterns. The machine might then to record the event as periodic breathing when "slow, effective" breathing might be a better phrase for you.

However, as I noted, I am not a doctor and would be happier if you discuss it with your doctor. As is always the case, if you encounter something unusual, then it is always best to check.

[DreamOn]

Dolpp, I agree with the others that it would be best to discuss your concerns with your doctor. CO2 dysregulation/centrals apneas can be caused by many different things -- certain medications, central nervous system disorders, heart or lung problems. Your central apneas may be pressure-induced (which happens for some people on regular CPAP machines too). As John said, it may be that your machine is interpreting your breathing pattern differently. That wouldn't surprise me, since your extremely low heart rate is so unusual, but everything should be looked at. The doctor may decide to order further testing.

You said that you were prescribed pressure of 12/8, but in your original post in this thread you stated, "I titrated myself to a different pressure". What are the BiPAP settings that you are currently using? Is your machine still showing a high number of central apneas at that pressure?

As for pulse oximeters, I have the Contec CMS Model 50-E recording pulse oximeter, and I'm very happy with it. The finger clip is lightweight, has no wires, has oxygen and pulse alarms you can set, comes with software, USB cable and AC adapter. The lithium battery can be recharged via either USB or AC adapter. (It will have to be sent off for lithium battery replacement eventually, though.) User's manual says the battery will hold charge for 12 continuous hours. I purchased it at http://www.oximetersonline.com (currently $139.99, with free shipping). There are more expensive oximeters that are probably built better, but the one I have works fine for me, as I just use it occasionally. It measures pulse rate from 30 bpm to 240 bpm.

Here's a comparison chart that shows all the features of the various Contec oximeters: http://www.semedicalsupply.com/SPO2%20C ... 0Chart.pdf. And you can find the Contec oximeter user's manuals here: http://www.semedicalsupply.com/user_manuals.htm.

If you search the forum for "oximeter" you will find quite a few threads with people's reviews.

I don't think an oximeter is going to give you all the answers you need, so I do hope you discuss this with your doctor. But it can be a helpful tool. Please let us know what you discover.

[Dolpp]

Thank you all for your responses. I will definitely discuss my concerns with my doctor the next time I see him. I just know that he does not feel as though the software is worth anything and that my concerns will fall on deaf ears. I told him on my one month follow-up that I was concerned about the centrals and he said he doesn't trust the software and said that he was sure that the centrals that did show up on my PSG would go away after I got used to the BiPaP but they didn't according to the software.

I tried titrating myself with the bipap from 6-12 with a swing of 4 and it put my 90% I at 10 and my 90% E at 7. But my centrals were through the roof like 35-40 range so I just put my setting at a straight 8 because that is what my setting was before the bipap. My numbers are always under 5 and usually under 3 but I still feel really tired. I was trying to think of another option thats when I noticed when I was titrated with the Bipap it was the only time I had measurable REM sleep out of all of my sleep studies, and that the centrals were usually (not always) during REM sleep and thats when I posed the question. My thinking being maybe my numbers are good but i'm not getting into REM sleep and I need the BiPaP at 12/8 to get there.