Did Your Titration Produce Normal Sleep and Breathing?

I'm curious to know whether most PAP therapy users understand what it means to normalize airflow during your titration test. If you are under the impression that the goal is only to eliminate apneas and hypopneas, then you are missing out on a very important element that might prevent you from attaining the best sleep possible.

Years ago, it was determined that a more subtle form of breathing disturbance known as upper airway resistance (UAR) was an important component of breathing disturbances in patients with sleep apnea. Nowadays, the most common name for UAR in the sleep lab environment is flow limitation, and what's obvious if you look for it is the need to eliminate flow limitation along with apneas and hypopneas.

At our center, http://www.sleeptreatment.com, we aggressively seek to find the pressures that normalize the airflow curve, which technically for most patients means that the signal looks very rounded or elliptical while you are breathing in or breathing out. As I mentioned in a previous post, we routinely use bilevel, because we find it much easier to normalize both the inhalation and exhalation airflow curves by using a higher pressure when you breathe in and lower when you breathe out. Nearly all our patients report bilevel is much more comfortable as well.

Most importantly, we have seen many patients who were titrated at other labs, where their lab reports did not mention "flow limitation." Those labs may have only attempted to titrate out apneas and hypopneas. When we titrated these patients and sought to eliminate flow limitation events, they reported a much deeper sleep.

If you're curious about flow limitation and whether it might be affecting your sleep, I encourage you to check out my new book, Sound Sleep, Sound Mind at http://www.soundsleepsoundmind.com. The book has several graphics that show flow limitations and how they differ from apneas and hypopneas. The graphics also show what normal breathing should look like, whether you happen to be a normal sleeper or whether you are getting the optimal response to PAP Therapy.

Good Luck and Sweet Dreams

Barry Krakow, MD, blogging at http://www.sleepdynamictherapy.com

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

During my titration study, I had numerous "spontaneous arousals." I was titrated at 5, though I have moderate sleep apnea. This pressure did not work for me, and I am now at 9 cm H20. I've wondered if my spontaneous arousals were due to UARS-like phenomena and a too-low titration pressure and might be taken care of via a higher pressure.

My titration study was very poor quality, IMHO. I later showed it to a more knowledgeable tech and his comment was "What, did the tech doing your study just set your pressure and fall asleep herself?" He felt the pressure should have been increased beyond 5 cm H20.

Your perspective is an interesting one.

Yes, it is interesting. I do often times during the day find myself taking deep breaths or pausing between breathes longer than normal. I would not doubt that I have a poor rythm flow during sleep.

Is C-flex type expiratory relief adequate-or is BiPAP necessary? Are you successful in getting Medicare and insurance to pay for it or do patients have to pay out of pocket?

My doc didn't tell me squat. On my one-month follow-up, I discovered that he was clueless to the differences in the APAP auto algorithms between the major manufactures. In fact on my one-year follow-up visit, he didn't even see me ... he sent his nurse to interview me and still charged me the full $30 co-pay office visit. Yesterday I received a notice from my insurance that his office tried to bill the insurance for 3 types of surgical anesthesia and a special oxygen mask for that annual office visit … I don’t recall any of it during my interview with the nurse and I WAS wide awake the whole time! I intend to report it as fraud to the insurance.

Everything I have learned about my PAP treatment has come from this forum. My AHI is consistently under 0.5 but I seem to be doing fine relative to before treatment.

Can you please explain how bi-level machines reduce flow limitations better than an APAP with exhalation relief such as AFLEX?

Dreamstalker-I wondered the same thing and figure the answer to that question is in the book mentioned above. And yes I decided to order the book. It could answer some questions. Looked at Dr Krakow's website and liked his approach to SDB and mental health. His posted credentials look good. And someone just gave me an Amazon gift card ready to expire.
And it is great to have to have a sleep specialist check in here-even if Dr Krakow just raises questions without answers it give me something to look at. I pretty much ignore FLs-I can tell you my AI and HI for the past two weeks. But FL for last night????? Back to Encore.

Deleted-as the message I was referring to was also deleted.

krousseau wrote:Author of the post that appeared while I was doing my usual hunt & peck typing leads me to the conclusion that there is book promotion going on. Oh well, at least the book will pay for itself if I use it at bedtime in lieu of Ambien.
Dr Krakow also promotes a two tiered healtj care system by offering personalized sleep service to his deep pocket clients ie insurance does not cover it. For a price it looks like paying the VIP fees lets you see the doctor for your followup visit. Check out the website to see VIP service-maybe I'm on a slow simmer.

Sounds like this doc is out primarily for the $. I do know some that aren't.

Mindy

Thank you for your great questions and comments. I'll try to respond to all of them.

1. Spontaneous Arousals. This is a key term from the field of insomnia research, and it is one that I and others have found to be a misnomer in many cases. That is, the arousal was linked to UARS when the proper respiratory monitoring system was used to detect subtle breathing events (flow limitation). There are spontaneous arousals, but my clinical sense tells me the term is often over used, because we've seen an enormous number of patients who had the similar experience being prescribed a very low CPAP pressure, who eventually needed much higher pressures to eliminate flow limitation events.

2. Daytime Breathing Rhythm. I am convinced that sleep breathing problems influence how we breathe during the day and how we breathe during the day influences how we breathe at night, but I do not profess to have a solution on how to use this information. I can only say that many patients have reported that they noticed an easier sense of breathing during the day once they experienced a successful use of PAP therapy.

3. Expiratory Relief. There is a huge controversy in the field about expiratory relief systems, such as CFLEX, etc. I'm sure they work well for some people, but the simplest way to understand these systems is to realize that they are like bilevel, that is CFLEX with a relief of 3 with a patient on a pressure of 8, might be equivalent to bilevel of 8/6 (a gap of 2 between the high and the low pressure). Now, the reason this point is important is that we've found that the gap between inspiratory and expiratory pressure on bilevel is greater than 3 in 90% of our prescriptions. In other words, during our titrations we find very few patients that get an optimal response to bilevel where the gap is only 2. Most of our patients have gaps between 4 and 6 and others are still higher. My own gap is 8. I'm not a respiratory physiologist, but my clinical experience has been that bilevel with the wider gap produces greater normalization of airflow compared to FLEX machines.

4. Medicare Coverage. All insurance policies have different policies on UARS, but Medicare does not usually cover it. However, with the new scoring rules from the American Academy of Sleep Medicine, some events previously scored as flow limitation are now scored as hypopneas, which are covered by Medicare.

5. Bilevel vs FLEX Part II. I don't think I can give a perfect answer to DreamStalker's questions, but I can share our clinical and research experience, which I think will clarify a lot. What we discovered about 5 years ago was that if you look very closely on the expiratory limb of the airflow curve (i.e. exhalation, breathing out), it's fairly apparent you can see typically 1 of 3 things. First, the signal will look normal, which means it will look rounded or elliptical, indicating smooth breathing. Second, is can look flattened, which is a sign of airway resistance and would be labelled expiratory flow limitation. Third, it can look irregular with a lot of little bumps or humps, indicating pressure intolerance, which likely means that the patient is having difficulty tolerating the experience of trying to breathe out while pressurized airflow is coming in.

And that brings me to the clinical pearl that led us to use bilevel. What we saw was that patients with anxiety and insomnia who also had sleep breathing problems, almost always exhibited pressure intolerance on expiration when we had them on CPAP. When we tried to give them relief with FLEX, they soon developed expiratory flow limitation instead of the breath normalizing. Finally, we started using bilevel and voila, we noticed that the expiratory curved rounded very quickly and as I noted above, the rounding seem to occur with relatively larger gaps of say 4 to 6 cm of water between the inspiratory and expiratory pressures.

6. Website, Sleep Center, & Book. Thanks for your comments about my book, website and sleep center. The center operates as any traditional center and we see patients both in the lab and the clinic, but we've found that moving patients through the lab as fast as possible makes for a more efficient treatment approach. So, in short, we do not have a two-tiered system. The VIP program is generally for out of state patients who either cannot use their insurance at our center or who want a more intensive treatment program. The website is a place where we hope to provide a great deal more services, forums, and knowledge, and along those lines for those of you who blog, you might be very interested in our new section http://www.snoozebusters.com where we hope to enlist the aid of fellow sleep patients to write about important topics in sleep that are often missed by the mainstream media. Regarding my new book Sound Sleep, Sound Mind, I look forward to any comments or reviews you may have about it. It took five years to write, and it's exciting to learn how people react to it.

7. Poll Results. I'm surprised somewhat by the poll results in that only 1 person reports having discussed flow limitation with their sleep providers.

Dr Krakow,

Thank you for your explanations. I'm curious about the debate about APAP Vs. CPAP for patients with cardiovascular disease and cardiomyopathy with congestive heart failure. At least one study showed a positive impact from CPAP but not APAP. IMHO, it was a fairly small study but it certainly is an intriguing question. And, that also raises the question in my mind of where BIPAP fits into this issue.

Any thoughts on this?

Thank you,
Mindy

Thank you for the answers. I'm looking forward to reading both books-should have paid for two day delivery. I have read Dement's book and did not feel it offered much for people with SDB. I'll read brfore bedtime.

Dr. Krakow, I read recently there are a couple of ways to measure air flow in a sleep lab study, and it seemed to suggest that one device can't accurately measure certain breathing or something. Don't all labs have the same equipment? I'm worried I spent money getting data that isn't complete. Is that possible?
Thanks
EM

The sleep study place didn't discuss anything with me. Just gave the report to my Dr... who basically knew little about the Study etc...

I started out with a high level Bipap and finally got to a ENT to explain that I didn't sleep on my back and that I thought I could use a lower pressure.... with the new RX I was able to get a much better machine and I've been on it ever since with good results.

I have had no follow ups (no surprise) and no one has ever looked at the data my machine puts out...

But I do feel rested unlike before and have been using it now for more than a year.

BarryKrakowMD wrote:... snip ...

3. Expiratory Relief. There is a huge controversy in the field about expiratory relief systems, such as CFLEX, etc. I'm sure they work well for some people, but the simplest way to understand these systems is to realize that they are like bilevel, that is CFLEX with a relief of 3 with a patient on a pressure of 8, might be equivalent to bilevel of 8/6 (a gap of 2 between the high and the low pressure). Now, the reason this point is important is that we've found that the gap between inspiratory and expiratory pressure on bilevel is greater than 3 in 90% of our prescriptions. In other words, during our titrations we find very few patients that get an optimal response to bilevel where the gap is only 2. Most of our patients have gaps between 4 and 6 and others are still higher. My own gap is 8. I'm not a respiratory physiologist, but my clinical experience has been that bilevel with the wider gap produces greater normalization of airflow compared to FLEX machines.

... snip ...

5. Bilevel vs FLEX Part II. I don't think I can give a perfect answer to DreamStalker's questions, but I can share our clinical and research experience, which I think will clarify a lot. What we discovered about 5 years ago was that if you look very closely on the expiratory limb of the airflow curve (i.e. exhalation, breathing out), it's fairly apparent you can see typically 1 of 3 things. First, the signal will look normal, which means it will look rounded or elliptical, indicating smooth breathing. Second, is can look flattened, which is a sign of airway resistance and would be labelled expiratory flow limitation. Third, it can look irregular with a lot of little bumps or humps, indicating pressure intolerance, which likely means that the patient is having difficulty tolerating the experience of trying to breathe out while pressurized airflow is coming in.

And that brings me to the clinical pearl that led us to use bilevel. What we saw was that patients with anxiety and insomnia who also had sleep breathing problems, almost always exhibited pressure intolerance on expiration when we had them on CPAP. When we tried to give them relief with FLEX, they soon developed expiratory flow limitation instead of the breath normalizing. Finally, we started using bilevel and voila, we noticed that the expiratory curved rounded very quickly and as I noted above, the rounding seem to occur with relatively larger gaps of say 4 to 6 cm of water between the inspiratory and expiratory pressures.

... snip ...

7. Poll Results. I'm surprised somewhat by the poll results in that only 1 person reports having discussed flow limitation with their sleep providers.

Can you post a couple of airflow curves that show the difference between using a 2 cm gap and a 4 or 6 cm gap between min and max pressure settings and explain how airflow is normalized or not in the two curves?

I'm not surprised by the poll results. Many of us end up here on this forum because we were not provided enough information to understand our treatment. Even more unfortunate are all those who have failed to comply with their treatment because they either have no internet access/skills or are simply ignorant in trusting the health system to take care of them.

Thanks for sharing your perspective here. So far, most of the members here focus mostly on tweaking their treatment to minimize apneas and hyponeas (typically by 1st controlling mask interface leaks then by auto titrating over long periods of time relative to sleep lab environment). Your take on flow limitations is interesting.

My sleep study report included apnea, hyponeas, and RERAs. In my first followup RERAs were mentioned as if they did not matter and were not mentioned during subsequent visits. I had the info from Encore. Consequently I did not look at FLs until yesterday.
I've looked at a sampling of flow limitations since starting PAP and FLs have dropped. Subjectively-I've had much less trouble with nasal congestion/breathing-both day and night. I've had lifelong allergies and attribute the improvement to breathing filtered, warm, humidified air; along with a boost from the pressure. I like to draw cartoons and the picture in my mind is my nasal passages ballooning slightly from the pressure.