RERA (Respiratory Effort Related Arousal)

[justacpapuser]

I don't have apnea (not breathing for more than 10 seconds) nor do I have hypopnea (not enough oxygen) but I do have RERA.
I guess it is the inability to breath (in my case due to obstructive air paths) while trying to do so which results in a near immediate arousal.

The treatment is the same, as the air pressure keeps the air ways "open".
I was just wondering how many people have RERA instead of apnea/hypopnea and how different is it (if at all) in symptoms, etc.

[The Choker]

Millions of people have it and most of them have not been diagnosed or have mistakenly been diagnosed with other conditions.

[Pugsy]

Do a forum search for UARS Upper Airway Resistance Syndrome and you will find that several members here are working with that diagnosis. Quite a few discussions about it back late winter, early spring.

[avi123]

See these about RERAs that I copied from the Mayo Clinic website.

Source:
http://www.clevelandclinicmeded.com/med ... ng/#cesec9

{I doubt it if you'll find info on this board as clear]


Upper airway resistance syndrome

UARS can cause symptoms similar to those found in OSA, yet this syndrome is considerably different due to the lack of oxygen desaturation found during sleep studies. Upper airway resistance syndrome was a term first applied to patients who were found to have excessive daytime sleepiness without a clear cause on a multiple sleep latency test, which was further documented by an overnight polysomnogram. These patients were often said to have idiopathic hypersomnia. After many of these patients were further tested with invasive polysomnography (including an esophageal balloon transducer and full pneumotachograph), they were found to have increased upper airway resistance. Resistance was indicated by increased negative esophageal inspiratory pressure.2

Definition

UARS is characterized by repeated arousals, due to upper airway resistance, that lead to excessive daytime sleepiness. This disorder often produces a snoring pattern termed crescendo snoring. When the crescendo snoring episode ends, an arousal occurs with rapid decrease in upper airway resistance; the snoring then disappears and stops for a period. UARS events are noted to be typically short: one to three breaths in duration. These events have been termed respiratory effort-related arousals (RERAs). In UARS, unlike in OSAHS, there is no evidence of oxygen desaturation.2 For the measurement criteria to be classified as a RERA, there must be a pattern of progressively increased negative esophageal pressure that is terminated by a sudden change in the pressure to a less-negative level and a sleep arousal. Furthermore, the event must last 10 seconds or longer.

Prevalence

The prevalence of UARS in the general adult population is unknown, yet it has been estimated to be as high as 10% to 15% when the definition is applied to adults who suffer from snoring and excessive daytime sleepiness.19 It has been suggested that UARS occurs in a less-obese younger population and more commonly in women than does OSAHS.2

Pathophysiology

Guilleminault and coworkers20 demonstrated that many nonapneic patients show a reduction in cross-sectional area of the pharynx during sleep. Reduction in airway area is sufficient to avoid hypopneas and apnea but enough to increase upper airway resistance. Patients with UARS suffer from increased airway resistance, which generates snoring and then leads to arousal episodes and ultimately to excessive daytime sleepiness.

Signs and Symptoms

Although patients with UARS share no standard clinical presentation, the cardinal symptom of UARS is excessive daytime sleepiness or fatigue. Some patients also complain of difficulty with concentration, morning headaches, impotence, difficulty sleeping, or restless sleep. They often report having repetitive nightmares, such as choking or being buried alive, which can suggest difficulty with breathing. Again, snoring is not a necessary feature of this syndrome because the upper airway resistance is due to a partial decrease in airway cross-sectional area; therefore, the airway walls do not have to vibrate and produce a snoring sound.3

Diagnosis

UARS should not be overdiagnosed. Three essential clinical features consistently have been used by investigators and authors to diagnose UARS: excessive daytime somnolence; an elevated EEG arousal index, with the arousal related to increased respiratory efforts; and a normal respiratory disturbance index (RDI) of less than five events per hour of sleep.21

UARS is present only if there are documented elevations in upper airway resistance, sleep fragmentation, and daytime dysfunction or excessive daytime sleepiness. The clinical complaint of fatigue or daytime sleepiness can be documented by an abnormal increase in the Epworth Sleepiness Scale (see Table 1 ) score to a value greater than 10 or by use of another validated sleep questionnaire. A low RDI is also needed to distinguish UARS from OSAHS. The elevated EEG arousal index related to increased respiratory efforts is the specific measurement that distinguishes UARS from idiopathic hypersomnolence.22 The clinical complaint of snoring (including crescendo snoring), increase in snoring intensity before EEG arousals, and clinical improvement with a short-term trial of nasal CPAP can be regarded as supporting a diagnosis of UARS.

The diagnosis of UARS requires full polysomnography. Although measurements of upper airway resistance were first used, based on the original definition of UARS, substitute measurements of effort and ventilation may be used as long as there is no evidence of hypopneas or apneas. A normal apnea-hypopnea index (AHI) of less than five events per hour of sleep should be seen on the polysomnograph. Additionally, EEG arousals should occur at a rate of more than 10 per hour of sleep and must be associated with increased respiratory effort (usually made by nocturnal esophageal pressure monitoring).

Current literature supports that esophageal pressures greater than −10 cm H2O are abnormal. The measurement of esophageal pressure is the gold standard for measuring respiratory effort and is the only consistent measurement reported for the diagnosis of UARS. Substitute measurements can include inductive plethysmography, strain gauges, oronasal temperature measurements, nasal pressures, and the carbon monoxide levels in exhaled gas. Arousals are documented from the EEG tracings and electromyography, although changes in heart rate, ventilation, and other measurements of autonomic activity may play some role in the future.3

Treatment

CPAP, surgery, oral appliances, and weight loss are possible treatment options for UARS. Ideally, the recommended treatment of UARS should be effective, relieve symptoms, and produce normalized studies after therapy. These therapies also should be covered by health insurance and have long-term effectiveness. Thus far, however, none of the proposed treatments has fully met these criteria.

Outcomes

Data in the sleep literature are not clear-cut regarding the efficacy, safety, and compliance of UARS treatment modalities, including weight loss, nasal CPAP, oral appliances, and surgery.

My notes:

It's a pitty that most sleep study clinics don't test for RERAs.

The sleep specialist Dr Barry Krakow wrote that Flow limitation = UARs= RERAs. If so, I assume that the Flow limitation ResScan graph that I get from my S9 Autoset machine equals or includes my RERAs:

[justacpapuser]

Thanks for the info.

However, I was wondering if someone has any ideas as to why my initial 2-3 weeks were very effective (6-7 hours of uninterrupted sleep), and then I started waking up after 3-4 hours.
I really thought it would be vice versa - initially hard to sleep but overtime sleep becoming easier due to adjustment to the mask/CPAP.

[Pugsy]

Going out on a long limb here...so just a WAG so to speak.
Perhaps any RERA issues were masked by the OSA issues and now that the OSA issues are well controlled the RERA issues now have reared their ugly head. I think that I read where some doctor says that anyone with OSA probably has some UARS issues as well...even if not officially diagnosed. It would be a reasonable statement I would think.
Perhaps simply other issues that affect sleep quality and sleep fragmentation and we know that list is very long.
Sleep disturbance issues are not limited to strictly OSA unfortunately. It would be a whole lot simpler if everything could be fixed with the mask and machine.

[justacpapuser]

Going out on a long limb here...so just a WAG so to speak.
Perhaps any RERA issues were masked by the OSA issues and now that the OSA issues are well controlled the RERA issues now have reared their ugly head. I think that I read where some doctor says that anyone with OSA probably has some UARS issues as well...even if not officially diagnosed. It would be a reasonable statement I would think.
Perhaps simply other issues that affect sleep quality and sleep fragmentation and we know that list is very long.
Sleep disturbance issues are not limited to strictly OSA unfortunately. It would be a whole lot simpler if everything could be fixed with the mask and machine.

Assuming the nasal pillows mask or nasal mask will be comfortable, I'll how it goes after that.
I really do hope that it is indeed the heat that causes this. I don't feel uncomfortable going to sleep with the mask but I do feel uncomfortable when I wake up.
Summer is upon us now and my apartment gets pretty warm (I use a fan which helps).
Am super-duper hoping that a more convenient mask will help. Even though I'm still better off now than without a CPAP, I do see/feel a direct correlation between my sleep quality and agitation/anxiety/restlessness during the day.
A great deal of it was eliminated the first few weeks but started coming back as my sleep deteriorated.
I will continue to update this thread as I have new things to report. Hold the fingers tight for me

[Pugsy]

I will cross my fingers and toes for you.
It may be partly heat and partly mask. You know our sleep is already really fragile and sometimes just the least little thing can really upset things.
There is a reason why I won't go down the FFM road. which I won't go into here but long ago I decided that some compromises are critical to getting sleep....gotta get the sleep first...worry about fixing the issues once the sleep comes and the issues come. I hope the new mask works out for you.

Being female and just turned 60..and with a strong family history of breast cancer...I opted for no hormone replacement therapy when the "change" came. Even now, I simply cannot sleep well at all if I am even the least little bit too warm.
Easy in the winter to make the bedroom an icebox...a lot harder in the summer time.

I think you will find that there is a lot of detective work along with this CPAP work. So many little things can affect how we sleep in a big way.

[robysue]

I don't have apnea (not breathing for more than 10 seconds) nor do I have hypopnea (not enough oxygen) but I do have RERA.
I guess it is the inability to breath (in my case due to obstructive air paths) while trying to do so which results in a near immediate arousal.

A clarification:

A hypopnea is when you are attempting to breathe (there is some effort to breathe as measured by the belts) but the air flow is significantly lower than it should be for at least 10 seconds. The usual assumption is that the diminished air flow in a hypopnea is caused by a partial collapse of your upper airway. It's often described as like trying to breathe through a very small straw. Hypoxia, on the other hand, is the word used to describe the status of your body or a part of your body when it does not have enough oxygen. Hypopneas may or may not lead to an O2 desaturation (a temporary state of hypoxia).

Scoring of hypopneas on NPSGs is, unfortunately, not uniform. The sleep docs diagnosing us with SDB all believe hyponeas should be counted---or at least some hypopneas should be counted, but which ones should count still seems to be a bone of contention. Which is why we've got the confusing mess of the American Academy of Sleep Medicine (AASM) having two official definitions for scoring hypopneas: The AASM Recommended Standard and the AASM Alternative Standard for hypopneas. See http://www.ncbi.nlm.nih.gov/pubmed/19238801 and http://www.journalsleep.org/ViewAbstract.aspx?pid=27368 for a scholarly discussion of how and when these two standards affect a patient's diagnosis of OSA as well as the formal definitions of the two standards:

• AASM Recommended Standard: A hypopnea requires at least a 30% reduction in airflow for at least 10 seconds AND a corresponding O2 desaturation of at least 4%. Such a hypopnea does NOT require an EEG arousal.
• AASM Alternative Standard: A hypopnea requires at least a 50% reduction in airflow for at least 10 seconds AND one or both of the following conditions: A EEG arousal OR a corresponding O2 desaturation of at least 3%. Note that under the AASM Alternative Standard, if there is a 50% reduction of airflow for at least 10 seconds which ends with an EEG arousal, it will be scored as a hypopnea---even if there is no corresponding decrease in the O2 saturation levels. Some labs will list these particular hypopneas as "hypopneas with arousal".

Of course, under both standards, the hypopnea has to occur during an epoch when the patient is ASLEEP according to the EEG evidence.

It's my understanding that Medicare requires hypopneas to be scored under the AASM Recommended standard, but that the folks working in sleep medicine are increasingly leaning towards believing that the arousals triggered by large numbers of "Alternative Standard hypopneas" can be just as damaging to the body as the O2 desats triggered by the hypopneas scored under the Recommended Standard. And it's also my understanding that some sleep doctors (such as mine) are deeply concerned that Medicare insists upon a 4% desat to score an hypopnea.

[JoeP]

Wow, thanks for the great info avi123, seems to be describing me. I am somewhat shocked that my sleep doc didnt mention the UARS. She seems to be on top of things but was really baffled about how I could have little to no OSA but still be so sleepy.

After 2 sleep studies and a multiple latency test we decided to give CPAP "a shot" to see if it would help and it has somewhat.

I have been on for almost 2 months, i have seen some improvement but not as much as I think I should. The last 2 weeks have been getting better, in fact last night i only opened my eyes twice all night. Maybe my body is finally getting used to the mask.

Are there any special approaches to treating the UARS with the CPAP?

[avi123]

[quote="JoeP"]Wow, thanks for the great info avi123, seems to be describing me. I am somewhat shocked that my sleep doc didnt mention the UARS. She seems to be on top of things but was really baffled about how I could have little to no OSA but still be so sleepy.

After 2 sleep studies and a multiple latency test we decided to give CPAP "a shot" to see if it would help and it has somewhat.

I have been on for almost 2 months, i have seen some improvement but not as much as I think I should. The last 2 weeks have been getting better, in fact last night i only opened my eyes twice all night. Maybe my body is finally getting used to the mask.

Are there any special approaches to treating the UARS with the CPAP?[/quote]


Joe, the following is my opinion:

Since the Exhale pressure is responsible for clearing the upper airway, keeping a CPAP at higher pressure could do it. Same with a BiPAP. Using Provent, set at exhale pressure of 10 to 20 cm could also do it.

[JoeP]

Interesting. I have been experimenting (with my Docs approval) with minimum pressures and A-flex settings. What I have found is that when i have the A-flex on I am seeing higher AHI numbers than when it is off. Which agrees with your statement regarding exhale pressure. When looking at RDI there is a smaller difference than with AHI.

Here are the results from Sleepyhead:

18 days with no Aflex @ 5 cm = 1.06 AHI (1.96 RDI)
13 days with A-flex @ 6 cm = 1.44 AHI (2.02 RDI)
11 days with A-flex @ 7 cm = 1.40 AHI (2.13 RDI)
8 days with no Aflex @ 7 cm = 0.89 AHI (2.00 RDI)


I am not sure where to go with my settings from here.

[Pugsy]

I am not sure where to go with my settings from here.

This is part of why the UARS thing is a bit tough. The data that the machines give you can't really help all that much with any UARS side of things as far as evaluation because it is so hard to spot. If you looked at the flow graphs long enough and zoomed in to see the very minor differences in flow...with time you might spot the flow reductions that might go along with UARS. It isn't easy to see anyway and the flow graphs have minor variations anyway when we sleep which are normal.

On paper your data looks good so no obvious need to change anything based on the data that we do see.
Feelings...they are a lot tougher to qualify. Even people with primarily an obvious OSA diagnosis don't feel the good numbers immediately...we can't expect UARS people to do any better. We can hope but the reality is that even with the best "numbers" we don't always feel them UARS being a factor or not. Sometimes it does just take time and that is so hard to accept. Seems like we humans need to have "proof" that all this work is working and our biggest proof is how we feel since that is the ultimate goal.

From what I have read it seems like UARS often needs more pressure to alleviate the minor flow reductions associated with it and these aren't flagged on the machine reports. Either not enough flow restriction or not long enough or whatever.
It's a relatively new diagnosis and not a lot of study has been available for evaluation. Not a lot of experience to draw upon.

There is of course Dr Krakow (I think is the name, out in New Mexico) who has developed some ideas on how to help resolve these issues. Some of which have been discussed here on the forum. You might check him out.
He advocates using a different machine and a really pricey machine at that which insurance is likely to squawk about.

Your pressure needs for resolving your OSA part of the diagnosis are relatively low. If you did want to experiment with a little more pressure it is doubtful that you would see a large change in the AHI...because it is really already quite excellent and minor changes from night to night are normal occurrences. If I were going to go down that road with experimenting with a little more pressure I wouldn't look to the AHI for much idea as to effectiveness but instead I would look at how I felt and that is so much harder to measure because so many other factors affect the quality of our sleep and thus how we feel. We can't put all our blame on feeling crappy in the OSA or UARS basket.

We have to look at all the other stuff too...like simply hours of sleep. I feel like crap today. Only got 5 hours of sleep. Woke up and couldn't go back to sleep. Rare thing for me. If I get 7 hours of sleep I feel okay but if I get close to 8 hours of sleep...I feel much better than "okay". Fragmented sleep also messes with how we feel...wake up often but go back to sleep? Well that still messes with sleep architecture and the sleep stages and thus the restorative powers of sleep.
Meds?....lots of meds have side effects that are the very same symptoms we have with OSA. There is a long list of stuff that can and will mess with our sleep and thus impact how we feel the next day.

You will need to take a long hard look at a bunch of stuff to see if anything outside OSA or UARS (if you have it) could also be impacting how you feel. If you have other issues like with hours of sleep or fragmented sleep or meds that mess with sleep...the cpap machine isn't going to fix those issues no matter what settings you use. Sure would be nice if it would but it simply doesn't.

[JoeP]

My OSA numbers were never high, I barely made the threshold for the sleep apnea diagnosis to start CPAP. For me it has always been an issue of Excessive Daytime Sleepiness and fragment sleep/non-restful sleep. I had hoped for some great results when first starting the CPAP. But now that I look back that was unrealistic, I didnt have severe OSA so the change to the CPAP wasnt going to make a dramatic difference. I have had to reset my expectations and started looking for the little things - not taking an afternoon nap, sleeping through the night with minimal wake-ups, staying awake for the whole drive home. I am just about sleeping through the night so I might just hold status quo for the next couple weeks until I feel that i am fully acclimated to the mask, then I may start fiddling with pressures again. My average pressure is about 8.6, the sleep doc said i could go up that for a min pressure but recommended not going over it.

i will definitely be doing some more reading on the UARS and will be discussing it with the doc at my 3 month follow-up

[Pugsy]

My OSA numbers were never high, I barely made the threshold for the sleep apnea diagnosis to start CPAP. For me it has always been an issue of Excessive Daytime Sleepiness and fragment sleep/non-restful sleep. I had hoped for some great results when first starting the CPAP. But now that I look back that was unrealistic, I didnt have severe OSA so the change to the CPAP wasnt going to make a dramatic difference. I have had to reset my expectations and started looking for the little things - not taking an afternoon nap, sleeping through the night with minimal wake-ups, staying awake for the whole drive home. I am just about sleeping through the night so I might just hold status quo for the next couple weeks

Smart thinking and smart move. Eliminate the known culprits first. They need to be eliminated anyway.

Fragmented sleep...I understand it all too well and it takes a lot of work even when you know the cause.

Yes, we often expect the machine to fix everything and tend to forget that it really only fixes one thing.
CPAP doesn't do such a great job of fixing bad sleep unless the sole cause of the bad sleep is sleep apnea. Most of the time we aren't lucky enough to have one culprit messing with our sleep.

You have time... you know your issues...you know that you have seen some improvement...you know you have to use the machine anyway...so give it some time and slowly work on the other issues as best you can.

I actually got the "severe" category for my OSA and it took me a long time and lots of work before I saw marked improvement like I had read about. Those people you read about that wake up the first morning and feel like a totally new person and want to go run a marathon...well those people are very, very lucky. Most people it takes some time.
I used to laugh and tell people that after using the cpap machine I still didn't feel like running a marathon but at least when I wake up now I don't feel like I just ran a marathon.