UARS Discussion

Premiere Discussion Event Barry Krakow, MD Sep 2, 2021
premiere discussion event UARS with Dr. Barry Krakow

The below text is edited and reordered. See the above link for the full text

For our first Discussion, Thursday evening, September 2nd we will delve further into the problem of UARS, one of the most common issues for which patients seek my advice and coaching. Comments will open up approximately 15 minutes in advance of the scheduled start time (8 pm Eastern time zone), so individuals can begin asking questions. The Discussion will go for one hour.

Welcome!

KEF Do you believe there is some connection between UARS and trauma or prior insults to the autonomic nervous system? Such that people with a narrow airway and this trauma are more likely to develop UARS than those with a narrow airway but no existing nervous system dysregulation?

Barry Krakow, MD The big issue of how to eradicate the flow limitation, which means to round the airflow curve, theoretically can work with even CPAP even though it usually does not. The big reason CPAP doesn't work is once you get to the higher pressures needed to round the curve, the patient cannot tolerate these settings while exhaling; and for this reason alone bilevel options are needed.

The distinction between BPAP, ABPAP and ASV is a case-by-case issue. We have seen that those with highest levels of anxiety are more likely to need ASV, but we've seen great results with auto-bilevel (ABPAP).

The connections between UARS and psychophysiological events/insults appears to be emerging in the research literature. When we published an article in Sleep & Breathing in 2002, we quoted Series article from 1992/1994 where he showed that artificial arousals to normal sleepers actually worsen their breathing, that is, led to greater upper airway collapsibility. Thus, we have always assumed that traumatic and other stressful life occurrences are factoring into the phenomenon of seeing such high rates of OSA/UARS in PTSD patients. Now, we're seeing other research papers coming out that are either quoting us quoting Dr. Series, or going back to Series articles and quoting his group directly on this same idea, namely, if wake someone throughout the night with arousals does it in fact worsen respiration. So far, things are pointing in that direction

Fred Bonjour How can we identify UAES(sic) UARS vs other forms of SDB?

Barry Krakow, MD If UAES is a type and the question is UARS, it requires the willingness of sleep physicians to carefully scrutinize the sleep study tracings for the classic flattening shape of the flow limitation curve. Simply put, apneas and hypopneas are easy to spot, but it takes more scrutiny to see a flow limitation event, because the volume decrease is smaller. Nonetheless, here's a very salient clinical pearl. In the 1990s, a group from NYC headed by Dr. David Rapoport showed that even when someone only has flow limitation, that is, no apneas and no hypopneas at all, the patients still suffered from daytime sleepiness that was corrected if not eliminated by aggressive treatment with PAP therapy.

Elizabeth Strickler Thank you for the information. Isn't it the pressure support on Bilevel/ABPAP that helps to reduce the flow limitations, by effectively raising IPAP but still having a lower EPAP?

Candace Cain What are some of the ways to reduce air swallowing/aerophagia?

Barry Krakow, MD Aerophagia (air swallowing) is a very big deal in PAP patients widely under-recognized and under-treated in many sleep medicine clinics. Just today I was talking with an individual with this problem, so I've decided to write a longer post on it next week or the week after. It's very obvious that most aerophagia has a cause, and if the cause is address there's a good chance it will go away. The most common causes of air swallowing are mask leak according to most sleep experts. In our experience, there are more common causes including underlying leg movements (periodic limb movement disorder), rhinosinusitis, allergic rhinitis, nonallergic rhinitis, mouth breathing, and reflux. A lot of patients with air swallowing may benefit from an ENT evaluation to clarify whether any anatomic findings could explain the air swallowing.

Elizabeth Strickler Yes, I've had the experience of CPAP not working to reduce flow limitations to an acceptable level, resulting in arousals.

Isn't it the pressure support on Bilevel/ABPAP that helps to reduce the flow limitations, by effectively raising IPAP but still having a lower EPAP?

Also, what is the typical range of pressure support needed to reduce flow limitations? The standard EPR 3 on APAP doesn't seem to be enough.

KEF Do you believe that “floppy epiglottis” can be a problem that causes/contributes to airway issues in some people?

Barry Krakow, MD There's no question that floppy tissues create greater susceptibility to OSA/UARS; however, in the epiglottis area we're getting down to the very bottom portion of the upper airway, so not being an ENT expert, I can't offer an opinion on that region. We do know of course that the soft palate is often targeted as a site of floppiness, which is why many have invested in the idea of surgery in this area. However, both old and new research do not provide encouraging results for those who undergo soft palate surgeries.

Candace Cain Could the higher pressures needed to round the airflow curve lead to air swallowing?

Barry Krakow, MD Correct on the issue of higher CPAP leading to discomfort on expiration. When we first starting using bilevel about 15 years ago (we stopped prescribing CPAP in 2005), we saw some very large gaps between IPAP and EPAP. Some patients would like 18/10 or even 18/8. In a few years when we were working with auto-bilevel (ABPAP), we noticed the gaps from pressure support were clearly narrower but rarely would they be 3, which often explains why expiratory pressure support of 3 is not that effective. A typical ABPAP patient might start out with 12/7 and Pressure Support of 3 or 4 when first prescribed, but then months later, these numbers might trend upwards

Unequivocally, higher pressures contribute to air swallowing, but it's often the case that higher pressures are NOT the cause. Does make sense? Probably not, but it appears as if higher pressures are just unmasking some other issue that may not have been recognized as the real culprit of air swallowing. I've worked with many patients who want to and need to lower the pressures because of this problem, but I caution them how important it is to look for other underlying factors, because ultimately the higher pressure might be needed for the best response.

Fred Bonjour You stopped prescribing CPAP in 2005, was that just for UARS or OSA in general?

Elizabeth Strickler Does the Pressure Support effectively lower the EPAP (and increase the IPAP)?

Fred Bonjour How much Flow limitation does it take to be significant? When can you say the UARS is treated?

Barry Krakow, MD There are generally speaking two types of sleep breathing patients. The first is considered the classic OSA patient who appears to have little anxiety. These patients snore and are sleepy during the day. You can put a mask on them and on night one they adapt instantly to PAP. Guess what? These patients are not very common. They are not rare, but they are not the predominant type of patient with a sleep breathing problem. Therefore, we never saw that many of these classic cases who do fine with CPAP.

Instead, the 2nd type of patient is much more common as far as we could tell. Individuals who show at least a bit more if not a lot more complexity to their sleep issues. In nearly all these patients we realized not only that CPAP was difficult for them, but we did research to show that they never actually adapted to CPAP in terms of comfort and residual sleep breathing events. I experimented with all these devices myself, and in 2005 when Puritan Bennett came out with a new bilevel device, it was abundantly clear it was better than CPAP objectively and subjectively. We even tested it in our lab against CFLEX and realized at that time bilevel was the way to go.

We know that some degree of flow limitation will be seen in people who are thought to be normal sleepers. That said, in patients who suffer from OSA, there is almost always residual flow limitation that if aggressively treated leads to better symptomatic improvement. So what does aggressively treated flow limitation mean? It means that the inspiratory and expiratory curves are rounded for more than 90% of the night, that is, the airflow curve would be called normal 90% of the night.

KEF Do you believe most people have had sleep breathing issues since childhood and if so, what is the best way (if any?) to check for UARS in children?

Elizabeth Strickler Does the Pressure Support effectively lower the EPAP (and increase the IPAP)?

Barry Krakow, MD Pressure support means the number that stacks on top of EPAP. So if EPAP is 5 and PS is 3 that means your IPAP is going to be 8 during that particular breath. Now, think about auto bilevel: what if your EPAP minimum is 5, but the machine detects you need greater EPAP say 7 because you turned on your back or you went into REM sleep? At that point for the next breaths you get EPAP of 7 but now the IPAP is up to 10 (7 + 3). make sense?

Elizabeth Strickler Yes, thank you

Reply

Fred Bonjour To be clear, by rounded you mean it look like an "ideal" breath in the flow rate curve?

Barry Is EPAP the main or only pressure that treats these events (as opposed to IPAP)?

Barry Krakow, MD I believe a lot more people are suffering from sleep breathing issues at much younger ages than is currently realized, probably because the symptoms are too "mild" to consider as a problem. Nonetheless, it's a shame more attention isn't given, because we would actually see huge improvements in reading skills and other cognitive tasks while seeing a decrease in certain behavioral problems. The issue of UARS diagnosis once again requires sleep docs willing to consider looking at flow limitation on their sleep study tracings.

Elizabeth Strickler I, subjectively, feel like I have less aerophagia when using the "for her" APAP setting. Are there algorithms on an Aircurve Vauto that make aerophagia less likely? Also, have you encountered patients who get aerophagia from too low of a pressure (needing more air)?

Fred Bonjour To be clear, by rounded you mean it look like an "ideal" breath in the flow rate curve?

Barry Krakow, MD Yes, rounded is optimal and normal. I think the word ideal would come up with sleep professionals who are unwilling to go the extra mile, but in our work we consider the goal was always to round the curve, because that's what normal looks like.

Fred Bonjour You have talked about CPAP, APAP, and BiLevel for UARS treatment. What about ASV? if so, when?

Barry Krakow, MD ASV is the Cadillac of devices, I believe, because its algorithm has some "magic" embedded within it. Remember, these are proprietary algorithms, so no one but the vendor has access to the info, although researchers try to demonstrate how a particular device might be reacting when it auto-adjusts. In my experience, personally and professionally, ASV is an amazing invention because at times it almost feels like nothing is there. You are just breathing as if there is no pressurized air. I've never felt that with any other device, but I know some people report that experience with other devices. Let me sum up this point by saying that usually 2 out of every 3 patients could do extremely well with ABPAP, but the final third could ONLY do well with ASV, meaning they failed everything else and when placed on ASV, they declared a night and day difference.

Barry Krakow, MD Great question on IPAP/EPAP. Most people may not realize that EPAP is generally there to eliminate apneas, but once the apneas are gone, they have now been transformed into hypopneas. Then, if you give more EPAP pressure, the Hypopnea could turn into a flow limitation. Thus, to get from flow limitation to normal breathing, we're talking about the highest possible pressure. That said, usually you raise the EPAP to eliminate apnea and some hypopneas and then we discover that IPAP is more involved in eliminating remaining hypopneas and the flow limitations. For these reasons, it's difficult to fine tune the settings to the optimal or rounded curves, which is why we always brought patients back to the sleep lab to see what it took to round their airflow curves 90% of the night.

Barry once you get apneas down near 0, how much greater pressure is needed typically to eliminate the flow limitation events?

Rambo my doc says that anyone with sleep apnea has UARS?

Barry Krakow, MD There is no set value for pressure settings on how to eliminate flow limitation above the EPAP. If there is no access to a sleep lab, it's all trial and error. The single most valuable monitoring system of efficacy is yourself. As I've reported in many forums as well as research papers, once you get very close to your optimal settings, you can change EPAP or PS on a device by as little as 0.2 or 0.4 units and notice huge differences in the way you feel the next morning. That turns out to be a very reliable indicator if the small change lasts several weeks or months as it often does.

Elizabeth Strickler I, subjectively, feel like I have less aerophagia when using the "for her" APAP setting. Are there algorithms on an Aircurve Vauto that make aerophagia less likely? Also, have you encountered patients who get aerophagia from too low of a pressure (needing more air)?

Current APAP settings are 7 cm (with EPR of 3), AHI under 1, flow limitation Med .29. If converting to Aircurve 10 Vauto...what are good settings to start with?

Barry how many days or hours of data should be analyzed in order to determine one's status with uars?

Fred Bonjour What about using the flowrate curve in ResScan or OSCAR to verify the roundness of the flowrate curve?

Barry Krakow, MD Regarding the last aerophagia question, there are devices that are better than others. For example, I've seen air swallowing be completely eliminated with ASV or improved with ABPAP, but as before, rarely it's the machine with the exception of CPAP, which can contribute to more air swallowing than most devices. Still, any device can trigger air swallowing, which is why it's so important to look for an underlying cause and not presume it's the device or pressure as the direct cause.

Barry Krakow, MD Absolutely software like Oscar or directly from ResScan can help, but let me ask you, "if the curve look rounded on Oscar, but you still felt sleepy during the day, would you believe the Oscar or would you believe your own experience?" I favor the personal subjective experience instead of chasing "numbers" so to speak, and I'm not convinced that the software is as quantitatively accurate as we would all like it to be

Reply Fred Bonjour There is always a point where you have to rely on how the user feels. "numbers" can only be chased so far.

Barry Krakow, MD Elizabeth, reminder this is an educational forum and answering your question could be interpreted as providing medical advice, so I cannot respond. Sorry

Elizabeth Strickler Thank you for what you are doing to help educate us and other about UARS.

Fred Bonjour1 min ago Please continue this series, it has been most informative. Thankyou

Barry Thanks for having this educational forum!

Barry Krakow, MD19 min ago This will be the final comment on the question of how much data is enough....hours, days, weeks etc. The answer may surprise you in that if you are moving in the right direction when you go through trial and error experiences on your own or with your sleep professionals guidance, you often only need 1 to 2 days to sort out whether what you've done is good vs good enough. The self-monitoring of your sleep, your sleep quality and the way you feel the next day provides an enormous amount of insight into what's going on. Unfortunately, too many people keep looking at their numbers believing it's akin to monitoring your BP where you would like to see it get lower. BP monitoring is fine, and so is monitoring your blood sugar levels. But, regarding treatment of OSA/UARS, the numbers often lie or tell half-truths. The key is know how you are improving and whether or not it's reasonable to expect more improvement. I should say that I have been fortunate in my life to have experienced many perfect nights on PAP, and the next day confirms just how perfect the sleep was. I'm not suggesting you can get that experience every night, but once you get it enough times, then you become very aware of what your goals are in trying to reach that level as often as possible.

Barry Krakow, MD P.S. I forgot that Rambo is always right, right? His mother is correct, nearly every patient who has been diagnosed with OSA has a component of UARS that often goes untreated.

Rambo you are too kind "

Barry Krakow, MD P.S.S. It is my understanding this is a permanent post now for future reading. Thank you all for participating. Good night and Sweet Dreams!

Donate to Apnea Board