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Dr. Krakow,

I want to apologize to you for the churlish reception I posted in your first thread.

Having read with great interest your subsequent posts and looked at some of your writings, I know you are helping a great many people. I was out of line smarting off at you. I should have sat back and just kept reading more.

You're definitely an asset to this message board and to the sleep field. I hope to have the pleasure of reading many more posts by you on cpaptalk.

I really do appreciate that you, a sleep doctor, are willing to discuss things extensively with us here.

I do apologize to you most sincerely.

Regards,

Laura (rested gal)

P.S. Perhaps as much of what won me over as anything.... I noticed you're a LAB RAT (lab ratting is a good thing in my book!!)

You wrote:
"I use the Breeze Nasal pillows and have rigged a little strap that wraps around the hard plastic mold where the pillow cushions are inserted. The straps are then brought upwards, gently, to better seal the pillows, and they have velcro ends, so i can stick them to headgear or a chinstrap near the sides or top of my head."

krousseau wrote:Amazon was speedy-here is a review based on a quick read.

I own the following books on sleep:

The Promise of Sleep - William C. Dement
Sleep to Save Your Life - Gerard T. Lombardo, Henry Ehrlich
No More Sleepless Nights - Peter Hauri, Shirley Linde
Snoring and Sleep Apnea - Ralph A. Pascualy, Sally Warren Soest
REM Illumination - Timothy Walker

Is there enough new material in this book to make it worth buying given the books I have? What new information can I expect other than the techniques around Sleep Dynamic Therapy? I have no problem shelling out some money for the book if I think I will get enough value from it (Still wish I could justify Dement's text 'Principles and Practice of Sleep Medicine' but $200 is a bit steep for a book)

I just looked through all of Dr K 's posts. Felt very priviledged and lucky. I also have been changing my 420e settings and I can quite relate to snoredog's impression on a higher pressure would not actually help with reducing the runs. However, I found something interesting with my data which is exactly what Dr K has been trying to explain and hence the need of a bipap:

The importance of finding the right pressure(doesnt mean the higher the better to reduce runs as well as turning on the FL1) and the right gap between the upper and lower pressure to reduce the runs. Now I am able to reduce my respiratory index considerably and feeling a lot better.

My dilemma now is if I were to buy a bipap, I would like to know how I can get to the right settings ie the exact upper and lower setting which will give the correct gradient like in Dr K' s case like 8.5cm to give a normal breathing curve. I find it very time consuming and difficult trying to look at the results and compare them after changing the settings.

Do you work out an upper setting first, then varying the lower setting?Is one night data good enough? Also there are so many possible combinations.

Just took my shower and I think I need to get a solution for my problem. It is certainly not something that I enjoy tremendously writing in a forum. I am just not that motivated and ?may be due to years of my sleep apnoea with no dream at night at all but luckily resolved nocturia after cpap rx!

Looking thr Dr K's post again and as he quoted below:

I've lived through this problem and I've breathed through it, and no other single factor enhanced my sleep quality to the level I currently enjoy and am eternally grateful for experiencing.

I would like Dr K to help me with getting the right setting when I get my bipap in the future. I am living in Australia. Is the optimal bipap setting known only through the sleep study or which machine can I get to provide me data to get to the right answer?

I am not sure whether Dr K can provide this service and I will pay for this service if it is available. It is interesting to know more but getting an answer ie the right setting would be really important which I would also be eternally grateful.

Hi Bman,

The right pressure is crucial to be successful in getting better treatment in SA. I'm also thinking about the bipap auto biflex xpap....for my long term plan.

As of now started with apap (the pressure setting is at 95%tile at16.5cm with 18.5cm which yeild good results at ahi of 4.2 for last 7 days given that <5.0 AHI is accepatable) as high respronics as a good start.

Just wondered where about you are? PM me for any more discussions...we are close by?

Dr.K was right about 2 things....1.The high pressure that creates anxiety 2.
the smooth curve of natural breathing a quality of treatment. All xpap machines has it's own algorithms c-flex, a-flex, bi-flex, event the dual-channels systems that still cooking in the research lab. Moreover, all brands has it's own pattern recognition of apnea counts. I am still concerning for the sensitivity of each xpap that able to detect the apnea and hypopnea given that any apnea occures less than 10seconds still does not take into counts. So, if the patient has lots of choppy apnea in less than 10 seconds than the patient could ended up in the worng treatment. Any comment are welcome?

Mckooi

Still reading through the whole thread, but an in progress comment -

Thank you!

I have never had an AHI of more than 1.2, but my arousal index was >40. I did not have a titration study, instead I was sent home with an apap to sink or swim with pressure at 4-20. My insurance will cover UARS, but apparently not a titration study. Obviously I quickly realized that this was stupid, and started changing my pressure incrementally based on my own assessment of my symptoms. I have selected an apap pressure range of 8-12, though I have had a recurrence of headache and anxiety lately that are making me think of upping my pressure again.

If I may, I would like to print out your original post and give it to my sleep doctor and primary doctor, I have already given them the "ten years later" article and some research on patient led titration, but it seems silly that I haven't had a titration study especially since I have almost a year of %100 compliance.

This was my favorite part:

"6. Quantitative Data. Reminder, please be very careful in how you make use of data from these machines. As a human being, you potentially have much greater sensors for figuring out your responses when you develop a very active and accurate "observing self." Then, you will see exactly how to rate your symptoms and how to gauge your responses to treatment. Your own assessment and intuition are often much more reliable than data about runs, etc, in my opinion, although over night sleep studies with good sensors and a great sleep tech often times are more reliable than anything else out there."

Too bad I just switched to a high deductible health care, don't fancy paying for a titration study out of pocket. Any one researching UARS in Minnesota, I would be willing to donate my airway to science! (Well, lend, not donate, I will need it back after a titration study...)

P.S. for about 6 months I haven't been able to log in, any one know why that might be?

Sorry to the bilevel believers: I don't buy the argument that bilevel is the best tool for SDB (sleep-disordered breathing).

It's still a mystery:While extolling the bilevel as the best treatment for SDB, Dr. Krakow, the originator of this thread, himself admitted in his own words that "Why bilevel works so well is still a puzzle".

So what does this means to us everyday average Joe/Jane cpap'ers? It means it's completely up to us to find out for ourselves the truth about bilevel--Is it really the best treatment?

"Lemme tell you right now, folks," (in Bill Clinton's low, hoarse voice) "that ain't true at all!"

OSA is caused by the colapsing of the airway--a physical/mechanical problem, pure and simple. And you know what it takes to fix it--pressurized air to prop up that airway all night long. And you also know exactly what minimal pressure you need to do that and, hopefully, keep the collapsing at bay thru out the night.

Now, lemme ask you this: Do you think it's a good idea to allow that pressure to dip lower than the minimal you need at any point during the night? No, you don't think so? In fact, no one ever thinks so.

But bilevels do just that! Every time you exhale, bilevels can potentially reduce your pressure to lower than your minimal. And no one can dispute that this can be a weak point that can be susceptible to collapsing of the airway. And that's not a good thing for bilevels.

Don't get lost in our own ever-growing, self-induced medical mumbo-jumbo's and forget the fundamentals. All these new-fangled inventions in variable pressure techniques, C/A-Flex, bilevel, etc, are to increase patients' comfort and improve compliancy; They do nothing to the real beast, the underlying physical problem with airway collapsing, per se.

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CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP

OSA is a subset of SDB ... not the equivalent. The new-fangled mumbo-jumbo is in confusing the two as the same.

DreamStalker wrote:OSA is a subset of SDB ... not the equivalent. The new-fangled mumbo-jumbo is in confusing the two as the same.

Thanks for pointing this out.

But don't you agree that if bilevel is not the best tool for OSA then it won't be the best tool for SDB since OSA is a subset of SDB?

khvn wrote:

DreamStalker wrote:OSA is a subset of SDB ... not the equivalent. The new-fangled mumbo-jumbo is in confusing the two as the same.

Thanks for pointing this out.

But don't you agree that if bilevel is not the best tool for OSA then it won't be the best tool for SDB since OSA is a subset of SDB?

I don’t agree.

I have never used a bi-level but from my limited understanding of them, it would seem logical that they could be properly set up to effectively treat OSA as good or better than an APAP or CPAP (whether by comfort and/or by minimum pressure needed to maintain airflow). Furthermore, even if it was not as good or better for OSA than an APAP or CPAP, it is illogical to infer that just because bi-levels might not be best for OSA they would not be best for SDB … again the two are not the same.

http://www.atsqol.org/sections/specific ... thing.html

http://www.nhlbi.nih.gov/health/prof/sl ... ion5a.html


Den

Hi All,

For these broad-base arguments of straight-cpap, c-flex, a-flex, bi-flex and auto etc would require the air pressures engineers and algorithms developers to answer these questions. None of the doctors are able to answers these questions due to lack of knowledge in the machines itself that develop by the particular companies.

Question 1) Is there anyone here has that experience in this field? Please comment.

Question 2) The Auto APAP machine is running at 4cm to 20cm air pressures. But if with abit of tweak it can go as high as the BIPAP 30cm. Anybody knows this? Please comment.
Mckooi

khvn wrote:Now, lemme ask you this: Do you think it's a good idea to allow that pressure to dip lower than the minimal you need at any point during the night? No, you don't think so? In fact, no one ever thinks so.

But bilevels do just that! Every time you exhale, bilevels can potentially reduce your pressure to lower than your minimal. And no one can dispute that this can be a weak point that can be susceptible to collapsing of the airway. And that's not a good thing for bilevels.

No, a bilevel with the EPAP pressure set correctly doesn't let the airway collapse at all.

As I understand it, most bilevel titrations in a sleep lab are aimed at first finding the pressure that eliminates all apneas. The EPAP pressure is set there and left there. Then the titration continues by raising the IPAP pressure only... until hypopneas, flow limitations and residual snores are eliminated.

khvn, I looked back at some of your previous posts, to see where you've gotten the idea that a bilevel machine is going to "potentially reduce your pressure to lower than your minimal."

That would depend on where the EPAP (expiratory positive air pressure -- the pressure being used when you exhale) is set. Set too low, then yes it could allow airway collapse. The same could be said about ANY type of cpap machine. Set the minimum pressure too low and airway collapse could happen with a cpap, and at times with an autopap, too.

I think you misunderstand how bilevels can have their two separate pressures set so that the airway can be held open just fine for exhaling as well as inhaling.

In another thread, you asked this, khvn --

"It seems that bi-level operates on the same principle an auto-PAP does. Otoh, I must be missing something, since if bi-level = auto-PAP then why do they make the bi-level's in the first place?"

I thought ozij's answer would have cleared up that misconception.

To add my answer, now... no, bi-level is not the same as autopap. Bilevel machines and autopaps (auto-titrating cpaps) are very different types of machines. They don't work the same way at all.

khvn, I do agree that a bi-level machine is not a silver bullet "takes care of everything" machine for every kind of sleep disordered breathing.

I don't agree, however, with your idea:

khvn wrote: But don't you agree that if bilevel is not the best tool for OSA then it won't be the best tool for SDB since OSA is a subset of SDB?

I think you misunderstand how the two separate inhale/exhale pressures of a bi-level machine can be set to prevent airway collapse both ways -- while inhaling and while exhaling. The same pressure is not needed for both in most people. That misunderstanding has lead you to the notion that a bi-level machine cannot ever treat OSA effectively. That's just not so.

For most people less pressure is needed to keep the airway open while exhaling than when inhaling. Bi-level machines can be set to two pressures that effectively take care of both -- EPAP for the lower exhale pressure, and IPAP for the higher inhale pressure.

As with any type of "PAP" machine, it depends on the expertise of the person prescribing the two pressures for a bi-level machine to choose the two separate pressures that will keep the airway open for both exhaling and inhaling. Or, in the case of people choosing to tweak their settings themselves, it depends on their level of expertise as well....how well they understand their own sleep disordered breathing, how well they understand bilevel treatment, how well they understand what each setting is there for and what the changes might do.

If a do-it-yourself-tweaker has other underlying health problems (COPD, for example, or CHF) -- they had better also have a very good understanding of the impact there might be on those conditions if they change any machine's settings from what was prescribed for them. That same caution holds true if they're going to choose, on their own, to switch to a different type of machine.

Lots to talk about, but let's cut to the chase and clear up the pressing singular confusion about bilevel. Read the abstract and if you are so inclined visit PubMed and you'll find that the whole article is there for free.

1: Chest. 1990 Aug;98(2):317-24.

Obstructive sleep apnea treated by independently adjusted inspiratory and expiratory positive airway pressures via nasal mask. Physiologic and clinical implications. Sanders MH, Kern N.

Division of Pulmonary and Critical Care Medicine, University of Pittsburgh School of Medicine.

Treatment of obstructive sleep apnea with nasal continuous positive airway pressure mandates simultaneous increases of both inspiratory and expiratory positive airway pressures to eliminate apneas as well as nonapneic oxyhemoglobin desaturation events. We hypothesized that the forces acting to collapse the upper airway during inspiration and expiration are of different magnitudes and that obstructive sleep-disordered breathing events (including apneas, hypopneas and nonapneic desaturation events) could be eliminated at lower levels of EPAP than IPAP. To test these hypotheses, a device was built that allows the independent adjustment of EPAP and IPAP (nasal BiPAP). Our data support the hypotheses that expiratory phase events are important in the pathogenesis of OSA and that there are differences in the magnitudes of the forces destabilizing the upper airway during inspiration and expiration. Finally, applying these concepts, we have shown that by using a device that permits independent adjustment of EPAP and IPAP, obstructive sleep-disordered breathing can be eliminated at lower levels of expiratory airway pressure compared with conventional nasal CPAP therapy. This may reduce the adverse effects associated with nasal CPAP therapy and improve long-term therapeutic compliance.

So, to put it diplomatically, the notion that bilevel doesn't have a potential role in managing SDB or OSA with greater precision is quite wide of the mark.

Also, harken back to the discrepancy between science and consensus medicine. Here is it is black and white 17 years ago...a study showing advantages to bilevel, yet as we can tell from the threads and from most people's experiences in sleep labs, this knowledge has not diffused into the medical community.

Rest Wishes,

Thanks for all the feedback, folks. But no one really addresses my real beef in this thread! And that is:

The low pressure setting (EPAP) in a bilevel is there for patient's comfort and does absolutely nothing to improve OSA treatment. At worst, it can even represent a weak spot that risks airway collapse. As such, for treating OSA, bilevels possess nothing more special or better than APAPs or even straight CPAPs.

This is contrary to claim that has been made about bilevels!