Do I need BIPAP?

[spitintheocean]

Regarding my centrals--I have never had a night with zero centrals. My lowest nightly index is 0.7, which has only happened twice. My highest nightly index was 13.3 per hour. The average (over 2 1/2 months) is 3.4 per hour.

Regarding AHI-- the lowest I've ever gotten was 2.6 (only once). The vast majority of my nights the AHI is well over 5, with the highest recorded at 17.7 (higher than I had during my sleep study before they hooked me up to cpap).

How do you know that your apneas are centrals as opposed to other causes such as positional induced, inaccurate titration, excessive mask leaks, apap therapy with too great a range set up for the equipment to recover in time for the next event, etc?

I'm curious since my Resmed apap equipment will only provide data on the number and duration of events without diagnostic capability of the cause.

[charliemack]

My sleep doctor changed me to bipap and my AHI went up instead of down. Now, I can't get my AHI down to where it was when I first started using a cpap machine.

Do these doctors really know what they are doing?

[cflame1]

charliemack... what machine do you really have?

profile lists an Resmed S8 Vantage and a Respironics humidifier

Please fix your profile and be specific.

[jnk]

My sleep doctor changed me to bipap and my AHI went up instead of down. Now, I can't get my AHI down to where it was when I first started using a cpap machine.

Do these doctors really know what they are doing?

Some do. Some don't. Either way, they should be able to explain what they are trying to do.

Don't judge the success of your therapy strictly by numbers, though--and especially not by home-machine estimates of AHI alone if you change machines. Going from one brand to another, for example, can change your numbers as estimated by the machine, but that difference may not reflect the effectiveness of your therapy so much as it reflects the difference in how brands provide numbers that are only meant for trending over time on that one machine.

In other words, once you are using a particular machine, then you slowly tweak to get the numbers as low as you can on that machine. That's how the numbers are meant to be used.

The only way to find out your actual AHI is by getting a PSG.

[jbn3boys]

How do you know that your apneas are centrals as opposed to other causes such as positional induced, inaccurate titration, excessive mask leaks, apap therapy with too great a range set up for the equipment to recover in time for the next event, etc?

I'm curious since my Resmed apap equipment will only provide data on the number and duration of events without diagnostic capability of the cause.

I'm just going by the reports I can get with my EncoreViewer software. And I'm basing my original question on the fact that I am still extremely tired, regardless of my CA numbers.

[allen476]

I apologize for not responding to your questions sooner, Allen. Life got a little crazy around here for a few days!

Know that feeling. Since it was nice weather here this weekend, I spent the majority of my time outside. I wasn't ignoring you.

The night my CAs were 13.3 my average pressure was 12.6 with a 90% pressure of 16.5. ON another random night, my CA was 6.9 with average pressure of 12.0 and 90% pressure of 14.9. Overall, for the full time on apap, the average pressure is 10.3 with 90% pressure of 12.9.

Average AHI for 2 1/2 months is 6.7, with highs of 12.2 (and 17 twice in the first week of therapy), and lows occasionally in the 3.x range.

Sounds like pressure induced centrals. Definitely turn the pressure down.

Thank you for your insight, and for clarifying what the "clinical correlation" is. That's what I was thinking it meant, but I really wasn't sure.

Thanks to everyone for your input. I think as soon as this cold subsides, I will see my PCP and ask for a trial on bipap. Maybe that will be the "golden ticket" to my finally feeling better.

Your welcome. Let us know how you make out. Just make sure that you take your data with you to the doctor. Take a printout of your worst nights and an average night along with the summary page showing your averages.

Allen

[jbn3boys]

Thanks again. I plan on calling my doctor, just as soon as this wicked cold subsides a bit. I could go in sooner, but I hate wearing those crazy masks! lol

[spitintheocean]

Just a quick clarification based upon my understanding:

An "apnea" (that's the "A" in AHI) is the complete cessation of respiratory activity for a period of greater than ten seconds. Most commonly, this stoppage in breathing is caused by the physical collapse of the airway and is regularly accompanied by restricted breathing "hypopneas" occurring during partial physical blockage. The primary purpose of cpap therapy in its various iterations (cpap, apap,vpap, bi-pap) is to resolve the physical blockage by forcing air pressure into the throat to 'splint' the passage open. The more severe the blockage, the higher the necessary pressure, with various techniques available to assist the user during exhalation to overcome the incoming air pressure.

"Centrals" are a specific sort of apnea where breathing ceases for periods greater than ten seconds, and there is no attempt to breathe ....... your brain stops sending the signal to the muscles that control breathing. Central apneas are much rarer than the more common "obstructive sleep apnea", should be diagnosed during a proper sleep study and are usually treated with bi-pap equipment.

I don't believe you posted any data about your leak rates. If you are encountering frequent leaks on a wide open apap machine the unit will compensate by increasing the air pressure without beneficial effect. Moreover, many people suffer sleep disruptions from the frequent cycle of rapidly escalating/falling pressures.

Another issue with apap machines is the speed with which they can respond to apneic episodes. This is the reason why many of the experienced participants in this forum will limit the range between the lower and higher settings to a range of four or less.

[jbn3boys]

I don't believe you posted any data about your leak rates. If you are encountering frequent leaks on a wide open apap machine the unit will compensate by increasing the air pressure without beneficial effect. Moreover, many people suffer sleep disruptions from the frequent cycle of rapidly escalating/falling pressures.

No, I did not post anything regarding my leak rates. But if I look back, my leak rates are consistently in the 20-22 range, with the "intentional" leak rate for my mask at pressures of 10-15 being 25-31. Obviously, if my leak rate it lower than the intended, then I am not having any problems with leaks, at least according to my understanding.

I am well aware of the different types of apnea/hypopnea. I have done a ton of research online since first realizing that I really did need a sleep study done. As for the centrals, I did have centrals present during my sleep study, recorded on the PSG. That's why I am concerned about them. Especially given the fact that I've read many places here that centrals are more common at pressures greater than 10 (which mine are nearly all the time). Since I experienced centrals during my sleep study, AND since I was given bi-pap treatment for part of the night of my sleep study, I'm questioning if I really DO need bi-pap, given the lack of improvement in my symptoms.

As for the pressure range, I understand that there are some who try to limit it. I also know there are others here who are most concerned with the lower limit only, and don't worry if the upper limit is high. Since my 90% pressure (according to my EncoreViewer) varies between 9 and 16/17, I have a hard time believing that a small pressure range would be an effective treatment. My understanding of the auto is that it can automatically sense the needs, and adjust accordingly. Maybe I need higher pressures when I sleep on one side vs the other, or maybe I need lower pressure on nights that I am more peaceful/less restless. If I have a small range, then I may not be getting the correct pressure based on each unique situation. That's just my opinion, and I am by no means an expert in apap! That's why I'm here. But, I've also seen that people are kind of equally split on the upper number for an auto pressure setting.

[spitintheocean]

I outlined the distinction between "centrals" and conventional apneas because you regularly referred to the frequency of your centrals and I wasn't sure if you understood the difference. My Resmed equipment does not report "centrals", just apneas and I guess that I presumed your equipment had similar limitations.

It's an important distinction since the remedy may be different based upon the cause of your apneas.

For the record, my average nightly pressure is 18.3 on an apap machine set between a narrow range of 17 to 19 cm with no ramp or expiration relief. My average mask leak rate is less than .02 L/sec and I rarely have more than one apnea per night. Higher pressures do not necessarily cause centrals. With a properly seated mask, the pressure isn't noticeable and rather than uncomfortable, I find that I fall asleep in less than a minute after donning the mask. I sleep on both sides and rotate from front to back while my apap pressure never falls to the lower setting of 17. My oximeter reports an average nightly pulse rate in the high fifties and blood oxygen levels regularly cycle around 97 and 98. I'm averaging 7.5 hours of sleep and never have to rise for nocturnal bathroom breaks.

Before treatment, I couldn't sleep longer than 45 minutes without waking in a sweat and having to visit the washroom, six to eight times a night. I dreaded going to bed but couldn't keep my eyes open, even nodding off at work during one on one meetings where I was doing the talking. My sleep test identified an untreated rate of 121 events per hour with oxygen saturation levels falling as low as 53%. Even during my second test where the R/T had established a straighline cpap of 16 cm, my mean oxygen saturation level was only 91.5% I too was tested during my initial sleep test on a bi-level setting presumably to determine whether expiration relief was needed to improve the results. I was prescribed a cpap machine fixed at 18 cm and began treatment in February 2009. Since that time there have been only two nights when I wasn't on the machine, once because of a power failure and the other because of a follow-up visit at the sleep lab.

Because I had already visited this site and read eveyrthing I could, I decided to go for an apap unit with detailed reporting capablity.

When I began my therapy I found the air pressure, particularly upon exhalation, uncomfortable and tried to run the machine at lower pressures. I used a long ramp (Resmed calls it settling) and exhalation relief (Resmed calls it EPR vs A-Flex) and set up my apap pressure ranges from 10 to 20. The problem with that was because I couldn't seem to get the mask set up properly, leaks caused while moving around at night were driving my pressures all over the place. While Resmed's S8 II Autoset only allows patient settings to 20 cm, the machine is capable of providing 30 cm in response to events. Unfortunately, the apap equipment needs time to identify an apnea and then respond by increasing pressure. Without belaboring the point, there are very good technical reasons to keep your apap within a limited range.

I apologize for the long-winded response to your last post, but it was intended to demonstrate that higher pressures do not need to cause centrals and that bi-level testing may be a routine element in your sleep lab's diagnostic arsenal. My leak rate of .02 L/sec appears to be substantially less than yours, but perhaps you are using a different scale. The Resmed software already takes into account the leak rate proscribed for certain mask types and I presumed yours would have as well.

You seem concerned that a wide range of pressure is necessary to obtain the best results. You may wish to consider that the majority of diagnosed OSA patients are prescribed a cpap unit with a fixed pressure. Many sleep specialists consider apap therapy to have limited therapeutic benefit while many long time participants of this forum, once satisfied with their own self-titrating experiments, operate their units in a very narrow range or even at fixed pressure

In any event, I get the sense that you have already made up your mind that you need a Bipap machine and are looking for others to support that decision. My inclination was to examine your use of ramp and exhalation settings, narrowing your air pressure range but increasing overall pressures to something like 11 - 15 but only after confirming that your leaks were being properly controlled. Give that a couple of weeks and see what it does to your apnea index. Or don't, it's your decision. I'll continue to sleep well at 18.3 cm with a an avarage of one single apnea per night never lasting more than 12 seconds.

[jbn3boys]

I outlined the distinction between "centrals" and conventional apneas because you regularly referred to the frequency of your centrals and I wasn't sure if you understood the difference. My Resmed equipment does not report "centrals", just apneas and I guess that I presumed your equipment had similar limitations.

I guess I thought I covered that by talking about both CAs and AHI. With Respironics machines, and the optional software, you can track each of the following individually: Central Apnea, Obstructive Apnea, Hypopnea, Flow Limitation, Vibratory Snore, Respiratory Effort Related Arousals, average pressure, 90% pressure, and leaks. So when I talk about CAs, I am talking about events that my machine recognizes as centrals.

My average mask leak rate is less than .02 L/sec and I rarely have more than one apnea per night.

Respironics machines do not calculate based on what mask you are wearing. Instead, they report total leak rake. Total leak rate is defined as intentional leak (what you need to have) plus unintentional leak (what is above and beyond what is necessary). You can find lists of different masks and what their intended leak rate is (based on pressure being used) on both the Respironics and ResMed websites. My leak rate is consistently lower than the intentional leak rate. Therefore, it is my understanding that my leak rate (as calculated by your machine) would be zero.

Higher pressures do not necessarily cause centrals.

I am aware of that. I've also read multiple places on these forums that it CAN effect centrals.

In any event, I get the sense that you have already made up your mind that you need a Bipap machine and are looking for others to support that decision.

That is not my intention at all. I came here looking for information and guidance. Instead, what I seem to have received, at least from you, is arguments.

My inclination was to examine your use of ramp and exhalation settings,

I do not use the ramp feature, and I have my exhalation set at 2 (out of 3) on my machine.

narrowing your air pressure range but increasing overall pressures to something like 11 - 15

I have no problem with trying that.

but only after confirming that your leaks were being properly controlled.

Now that I've realized we are talking about two different machines, with two different ways of addressing leaks, I think you can understand that my leaks are well controlled.

Give that a couple of weeks and see what it does to your apnea index.

I'm happy to try that. My only rush is due to the fact that my husband has requested that I get this figured out (i.e. changing to bipap IF that is what is truly needed) before the first of the year, when his medical insurance will change.

I'll continue to sleep well at 18.3 cm with a an avarage of one single apnea per night never lasting more than 12 seconds.

I'm glad for you that your therapy is working so well for you. I look forward to someday having the same good results. For now, I am still struggling. I'm sorry for any frustration I have caused you.

[spitintheocean]

"I came here looking for information and guidance. Instead, what I seem to have received, at least from you, is arguments"

Really?

Try and remember that I don't have a problem but I did take time from my busy schedule to ensure that you were aware that the most common recommendation for new members here who are struggling is to manage their leak rate, and then incrementally increase their pressure while tracking their data to ensure that the increased pressure provides positive results. Having reviewed my posts, I am still satisfied that I was polite and patient with your responses, even as you were turning phrases such as:

"Obviously, if my leak rate it lower than the intended, then I am not having any problems with leaks ........"

"I am well aware of the different types of apnea/hypopnea"

I attempted to educate you that higher pressures are nothing to be fearful of, but I do apologize for not recognizing in advance that the correct answer to your question was:

" No those pants do not make your ass look fat!"

[JohnBFisher]

... How do you know that your apneas are centrals as opposed to other causes such as positional induced, inaccurate titration, excessive mask leaks, apap therapy with too great a range set up for the equipment to recover in time for the next event, etc?

I'm curious since my Resmed apap equipment will only provide data on the number and duration of events without diagnostic capability of the cause.

You might want to read up on the latest generation of the xPAP units. They can in fact detect if the apnea is a central event or not. One manufacturer uses a pulse of air periodically to determine if the airway is open or not. As I understand it, another listens for heartbeats during the apnea event.

Of course, what is important is to recognize that without all of the rest of the monitoring the best that can be said is that the apnea is a "clear airway" event. It might be a central apnea. But it might just be an apnea that occurs during sleep onset or transitioning from sleep to wakefulness. During a polysomnograph those are NOT scored as central apneas.

That's the biggest gripe I have with these machines that they often confuse folks. It is often easy to discern if the apnea may be related to sleep onset, since they tend to cluster together.

More on that in a bit for the original poster.

[JohnBFisher]

... I attempted to educate you that higher pressures are nothing to be fearful of, but I do apologize for not recognizing in advance that the correct answer to your question was:

" No those pants do not make your ass look fat!"

To quote a phrase:

Really?

While I can understand the frustration you must feel, remember how you felt when you were not getting enough sleep. Sometimes the best response is to reach out to the rest of the forum to ask to see if someone else might be able to tackle the questions. I know you put a lot of effort into your replies, but somehow the two of you were not meeting in the middle. It happens.

To that end, I will offer my thoughts and see if it helps. And I invite others who might be able to offer their thoughts.

[JohnBFisher]

jbn3boys let me first recount some facts:

• You have been using your unit for 2 1/2 months (or more by now).
• You continue to feel about the same as when you started (if not worse).
• You use a Respironics machine
• You use Encore Viewer which reports an average AHI that ranges from 7 to 12
• Encore Viewer shows central apneas
• The pressure range varies from 9 to 16/17

You also asked a some questions:

• Should I be asking to be switched to bipap, based on the sleep study report (specifically in regard to the rem stage) and the fact that I am still not feeling rested?
• If so, who should I be contacting first? My RT at my DME (who is very good), my PCP, who Rx'd the cpap machine, but really doesn't know much about them, or the sleep doc, who only read the results, but has never seen me?
• If I need to make this change, I'd like to do it as soon as possible, so all the kinks can get ironed out before the end of the year.

Okay, the last is not a question as much as it helps set the stage.

Now some thoughts and answer to "What would I do in your shoes?". As you well know, I am not a medical professional. I've just been down this type of road before. So, this is just based on my own personal experience and how I tackled similar issues.

First, let's tackle the central apneas, since they often create confusion. I know you understand about central apneas. What is key to know is that we often experience what appears to be central apneas during the transition from wakefulness to sleep. And then again when we awaken. Why? The mechanism used to control breathing is different when we are awake and when we are asleep. During this transition there is a "hand off" that often results in "central apneas". During the sleep study those central apneas are automatically discounted. We normally just fall asleep and then our breathing stabilizes. Here is an article about that:

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

Of course, if those central apneas are profound enough, you may not be able to reach sleep. That was one of my problems. I would stop breathing so long that my BiPAP unit thought I was no longer breathing. So, after a minute of not breathing my BiPAP would turn off. Not a good thing to have happen over and over and over. So, if it is a problem, then certainly it should be addressed.

HOWEVER, I do not sense that you are overly worried about the central versus obstructive versus hypopneas. One sentence of your stood out for me:

... I'm basing my original question on the fact that I am still extremely tired, regardless of my CA numbers. ...

So, let me get back to your questions.

... Should I be asking to be switched to bipap, based on the sleep study report (specifically in regard to the rem stage) and the fact that I am still not feeling rested? ...

Rather than worrying about BiPAP or CPAP or APAP, it is usually best to present that you still feel poorly. Present the symptom. THEN note that it appears from the sleep study when you were on BiPAP you had more REM sleep. Then ask "Would BiPAP be an option to help?" Present the symptom / concern and something that was noted in your sleep study. Otherwise, it feels as if you are trying to diagnose yourself. And the fact is that you clearly do not feel any benefit from the current therapy. The contined AHI over 5 is an indication it is not as effective as it should be.

... Who should I be contacting first? My RT at my DME (who is very good), my PCP, who Rx'd the cpap machine, but really doesn't know much about them, or the sleep doc, who only read the results, but has never seen me? ...

To whom should you address the question. You might want to ask the RT is they have an BiPAP auto that you could borrow / rent for a month to see how it does. That might provide some hard evidence one way or the other. It might also be an option to determine if it will help.

But I would present the whole issue to your PCP, who prescribed the therapy. The sleep doctor would probably send you back to your doctor (to avoid issues with insurance companies). Your PCP may refer you to see the sleep doctor. Or you might be able to talk your PCP into a BiPAP trial. Either way, it generally works best to go to the prescribing doctor first.

... If I need to make this change, I'd like to do it as soon as possible, so all the kinks can get ironed out before the end of the year. ...

You also note that you should make the change happen fairly quickly, due to a change in insurance companies. In fact, that can make it easier to switch machines. They new company might require another sleep study. It might be necessary to prove the validity of BiPAP. Sometimes they are more than willing to pay for the sleep study to avoid paying for more expensive equipment.

Anyway, this is how I would tackle this issue. And in fact it's what I did about 18 years ago when I switched from CPAP to BiPAP. In my case an additional sleep study was needed to show that I had lots of spontaneous arousals on CPAP and many fewer with BiPAP. But it's different for everyone.

In summary, I would first do some legwork with the RT to find out if a BiPAP trial is an option. Then I would go back to your PCP, note that you continue to feel poorly, that your AHI remains higher than 5, even after 2 1/2 months. Also note that you use it all the time, that you have no significant leak problems. Include some of the reports to show what you feel. But don't go overboard with the reports. Rather focus on "What do we need to do to help me feel better?" And as I noted your new insurance might actually make the change of equipment easier.

Hope that helps.