CO2 Washout ???

[Velbor]

Snoredog, many thanks for that link to the ResMed vpapadaptsv video. Excellent.

I understand that CO2 level is one of the primary respiratory drivers for most people. And I understand that lower xPAP pressures (with correspondingly lower flow rates) can theoretically reduce CO2 clearance from the mask system, and that some masks do a better job of CO2 clearance than others.

So I can understand that under certain (generally undesirable) conditions, xPAP use can result in some degree of CO2 increase. But I must admit to still failing to understand how xPAP use can LOWER CO2 levels BELOW what they would ordinarily be with "normal" breathing.

Therefore I would greatly appreciate clarifications of such statements as:

It may also be true that use of some mask interfaces can exhaust too much CO2 out of your system essentially vacuuming CO2 out of your system including that contained in the lungs.

What mechanism would cause this?

because of the higher than normal outside air pressure that is used in cpap .... there is more quantity of effective air circulated thru your lungs and this increases more removal of CO2 from your lungs than when you are not using xPAP

Is there evidence that tidal volume is increased by xPAP at usual (under 20cm) pressures?

These are examples of what I thought I was hearing in a number of previous posts, which led to my starting this topic. I still fail to understand how xPAP might cause a "below normal" lowering of CO2.

I shudder to think of people modifying the venting systems of their masks (either + or -) without a GREAT deal of understanding of the potential consequences.

Thanks. Velbor

[Snoredog]

Snoredog: I find it interesting that you seem to have a pretty complex sleep issue, including centrals, yet find that one of the least expensive machines , Goodnight 420 E, seems to work best for you. I have been looking at getting a second machine for travel for my BIPAP ST, but have hesitated because of the $5,000 cost of the auto bipaps with ST. Do you find that with your machine that your CO2 is regulated to where you don't need the ST? Just curious - I find your theory extremely interesting and am exploring how it might apply to others with centrals - the ST is working OK but I don't think it is giving me the best results and my centrals continue to be high, forcing the machine initiated breaths to be high. It is all inter-related somehow and that all seems too complicated for my sleep doctor (or his nurse who is the "gate-keeper"). Right now I am leaning towards trying the Bipap Auto SV or Bipap AVAPS, but don't want to pay $5K out of pocket unless pretty sure it is the right thing for somebody with limited obstructive events, but higher hyponia and centrals.

If I go by the results of my 4 PSG's, I have to conclude I have a form of CSDB, I have an intolerance to CPAP with CA's and Mixed apnea, but I conclude a very mild form of it. I am post stroke one of the characteristics found with CDSB, but I don't really believe the stroke played any part of my SDB, I think it is quite the opposite, SDB contributing to the year of TIA's and finally 2 strokes. My O2 levels during my first PSG were in the 65% range. My AHI wasn't all that bad at 72 per hour, in addition to that I had spontaneous noted at 29 per hour.

I've tried CPAP, never could find a set pressure that would work for any amount of time. Problem with that was I was awakening 3 or more times per night, many times in a full sweat and panic. That was a Remstar Pro, then a 420S, I then tried autopaps starting with a 420e probably the first one cpap.com ever shipped, it died on me and started operating erratically after 3 days use. I sent it back where I exchanged it for a Remstar Auto tank (non-Cflex) at my request. Next, I bought a Resmed Spirit S7, that was also pretty much a disaster for me. All it would do was run up in pressure as soon as I turned it on. I sold that one to kteague (sorry Kathy ). Later I updated the Remstar Autos to newer versions as new firmware came out. Went from non-Cflex to Cflex to Aflex. My BIL also has OSA and we'd swap machines around to try different machines. Think I owned 3 or 4 versions of the tank version of the Remstar Auto including a M series (actually 2 M series, one Cflex Auto and finally Aflex). Cflex wasn't so bad but Aflex simply doesn't agree with my SDB condition, similar result as seen in the lab with bilevel sleep became a train wreck (shameless plug: have the Aflex For Sale complete setup, w/humidifier extra tanks, including EncorePro 1.8.49 and reader, PM me if interested).

I have also been titrated on Bipap during my last PSG, didn't do so well with it, don't know if it was lack of experience by the tech or what but they tried bilevel and went back to cpap as sleep came apart. But I don't think they even knew about CSDB during that last PSG as I haven't been back to see my sleep specialist in over 6 years and don't intend to return any time soon.

Why I selected the 420e. Note: Current 420e is my 2nd 420e and 3rd if you want to count my 420s I owned in the past. It was only after trying everything else and understanding how they functioned did I return back to the 420e. My theory is with CSDB you want to treat the obstructive events seen and avoid any response to CA seen. More difficult thing to do with mixed apnea, but doable in my case.

I found the 420e has the settings and technology I need to treat me the best. You can control and limit how it responds to Flow Limitation, you can control how it responds to Apnea and control how it responds to obstructive apnea over 10 cm and/or if CA's are a problem limit apnea response below that threshold. No other machine on the market other than the new Sandman Auto can you tweak those parameters which is what allowed that machine to work for me.

CA is not my primary disorder, I don't have any waxing or waning commonly found with CSR nor do I think it would remotely work in that case. If your disorder is primarily CA or CSDB you need a machine that can manipulate and stablize your breathing in order to eliminate the CA. With the 420e and how I have it set up, it effectively treats my OSA while leaving the CA's alone. I keep my Minimum pressure low, limit how it can respond to apnea and flow limitations and use a mask I know retains more CO2. I know from years of use and observing reports, my apnea threshold is 9, if I go over that at the wrong time I'll have all kinds of CA's. With the Silverlining reports I can see my results. I lowered Command on Apnea from 10 cm to 9.0 cm, disabled IFL1 which is command on Flow Limitation and it pretty much keeps CA's to non-existent or only 1 or 2 per night, I can live with that.

So will it work for you as backup? I cannot say without looking at your daily reports and knowing your SDB condition. You have to know what your current machine is doing, with a ST it will switch from Spontaneous mode to Timed backup mode in the presence of CA. 420e doesn't do anything of the sort it simply does a better job at differentiating the difference between obstructive and central events. For the latter it doesn't do anything where your ST might switch to Timed backup mode if it senses you have stopped breathing. If your machine is switching several times per night it may not work for you, it may if you spend majority of time in Spontaneous mode and don't have a loss to spontaneous respiratory drive. If you have any AHI info from your current machine that would be helpful, just understand there is no mode switching should you stop breathing as with your current machine, but I don't know how you have that set up as it can be in CPAP, BIPAP, S or S/T mode. If it is being run in S mode then you don't have any timed backup to revert to even if it is set up.

But if I was to choose any other non-ST machine for emergency use it would be the 420e or the new Sandman Auto, in fact I'd lean towards the Sandman, they surely have made improvements to it over the 420e. From seeing the reports I'd have to say they have only improved upon it while I still prefer the 420e's form factor.

My pressure is low usually under 10 cm, my titrated pressure was 9 cm 8 years ago still is today. But there are times the 420e reports going up as high as 14 cm to take care of hypopnea or chase a snore but not often.

[Snoredog]

Snoredog, many thanks for that link to the ResMed vpapadaptsv video. Excellent.

I understand that CO2 level is one of the primary respiratory drivers for most people. And I understand that lower xPAP pressures (with correspondingly lower flow rates) can theoretically reduce CO2 clearance from the mask system, and that some masks do a better job of CO2 clearance than others.

So I can understand that under certain (generally undesirable) conditions, xPAP use can result in some degree of CO2 increase. But I must admit to still failing to understand how xPAP use can LOWER CO2 levels BELOW what they would ordinarily be with "normal" breathing.

Therefore I would greatly appreciate clarifications of such statements as:

It may also be true that use of some mask interfaces can exhaust too much CO2 out of your system essentially vacuuming CO2 out of your system including that contained in the lungs.

What mechanism would cause this?

because of the higher than normal outside air pressure that is used in cpap .... there is more quantity of effective air circulated thru your lungs and this increases more removal of CO2 from your lungs than when you are not using xPAP

Is there evidence that tidal volume is increased by xPAP at usual (under 20cm) pressures?

These are examples of what I thought I was hearing in a number of previous posts, which led to my starting this topic. I still fail to understand how xPAP might cause a "below normal" lowering of CO2.

I shudder to think of people modifying the venting systems of their masks (either + or -) without a GREAT deal of understanding of the potential consequences.

Thanks. Velbor

I agree with the caution, reason my first response to this thread was:

this discussion can become dangerous for some patients so no experimentation should be attempted with your equipment.

Using a mask that retains more CO2 is only one aspect of it, Bilevel is also required to manipulate tidal volumes from the machine side, but it also has to better adapt to the CA seen.

You might want to read this thread, it was one of the first out on the topic:
http://www.talkaboutsleep.com/message-b ... hp?t=13557

There have been many more writings and claims since many explain what it is but they don't get into the nuts and bolts on how it is controlled through CO2 retention as the original paper.

Shortly after this all the CPAP manufacturers came out with their AdaptSV machines to finally address it and CSR which was a major breakthrough in my opinion, before that it was hit or miss with therapy. For a lot of people their heart failed before they could get things stabilized.

[feeling_better]

Snoredog, many thanks for that link to the ResMed vpapadaptsv video. Excellent.

because of the higher than normal outside air pressure that is used in cpap .... there is more quantity of effective air circulated thru your lungs and this increases more removal of CO2 from your lungs than when you are not using xPAP

Is there evidence that tidal volume is increased by xPAP at usual (under 20cm) pressures?

I do not know if the tidal volume is defined at some standard pressrue. Otherwise, even if the tidal volume is not increased, at the higher pressure there is more air. Consider this: when you go high altitude, you get oxygen deprived... Higher pressure is like to exactly like going lower than sea level. About 2.5 cm of pressure is like at 1000' lower.

I shudder to think of people modifying the venting systems of their masks (either + or -) without a GREAT deal of understanding of the potential consequences.Thanks. Velbor

It is quite understandable your concern, and that is valid. However most people do not mind at all to switch from one mask to another without even giving any thoughts to the actual 'effective CO2 removal ratio'. I belive a mask like the headrest, where there is a large dead space may have a lot more CO2 rention than a pillow system like Optilife!! It is a shame there has been no standard established for this CO2 washout per pressure setting table. Currently it depends on the leak rate, the dead space, and the distance/geometry/position of the vent port with respect to the nasal openings.

It would be very complex to model this mathematically. But it is very easy to objectively measure this by a company with an instrument. Put a dummy breathing machine (simulating a patent) which adds a fixed % of CO2, replacing the same O2, and measure after some time when steady state conditions are reached, the CO2 concentration of the air entering the dummy.

[epo]

Snoredog: I find it interesting that you seem to have a pretty complex sleep issue, including centrals, yet find that one of the least expensive machines , Goodnight 420 E, seems to work best for you. I have been looking at getting a second machine for travel for my BIPAP ST, but have hesitated because of the $5,000 cost of the auto bipaps with ST. Do you find that with your machine that your CO2 is regulated to where you don't need the ST? Just curious - I find your theory extremely interesting and am exploring how it might apply to others with centrals - the ST is working OK but I don't think it is giving me the best results and my centrals continue to be high, forcing the machine initiated breaths to be high. It is all inter-related somehow and that all seems too complicated for my sleep doctor (or his nurse who is the "gate-keeper"). Right now I am leaning towards trying the Bipap Auto SV or Bipap AVAPS, but don't want to pay $5K out of pocket unless pretty sure it is the right thing for somebody with limited obstructive events, but higher hyponia and centrals.

If I go by the results of my 4 PSG's, I have to conclude I have a form of CSDB, I have an intolerance to CPAP with CA's and Mixed apnea, but I conclude a very mild form of it. I am post stroke one of the characteristics found with CDSB, but I don't really believe the stroke played any part of my SDB, I think it is quite the opposite, SDB contributing to the year of TIA's and finally 2 strokes. My O2 levels during my first PSG were in the 65% range. My AHI wasn't all that bad at 72 per hour, in addition to that I had spontaneous noted at 29 per hour.

I've tried CPAP, never could find a set pressure that would work for any amount of time. Problem with that was I was awakening 3 or more times per night, many times in a full sweat and panic. That was a Remstar Pro, then a 420S, I then tried autopaps starting with a 420e probably the first one cpap.com ever shipped, it died on me and started operating erratically after 3 days use. I sent it back where I exchanged it for a Remstar Auto tank (non-Cflex) at my request. Next, I bought a Resmed Spirit S7, that was also pretty much a disaster for me. All it would do was run up in pressure as soon as I turned it on. I sold that one to kteague (sorry Kathy ). Later I updated the Remstar Autos to newer versions as new firmware came out. Went from non-Cflex to Cflex to Aflex. My BIL also has OSA and we'd swap machines around to try different machines. Think I owned 3 or 4 versions of the tank version of the Remstar Auto including a M series (actually 2 M series, one Cflex Auto and finally Aflex). Cflex wasn't so bad but Aflex simply doesn't agree with my SDB condition, similar result as seen in the lab with bilevel sleep became a train wreck (shameless plug: have the Aflex For Sale complete setup, w/humidifier extra tanks, including EncorePro 1.8.49 and reader, PM me if interested).

I have also been titrated on Bipap during my last PSG, didn't do so well with it, don't know if it was lack of experience by the tech or what but they tried bilevel and went back to cpap as sleep came apart. But I don't think they even knew about CSDB during that last PSG as I haven't been back to see my sleep specialist in over 6 years and don't intend to return any time soon.

Why I selected the 420e. Note: Current 420e is my 2nd 420e and 3rd if you want to count my 420s I owned in the past. It was only after trying everything else and understanding how they functioned did I return back to the 420e. My theory is with CSDB you want to treat the obstructive events seen and avoid any response to CA seen. More difficult thing to do with mixed apnea, but doable in my case.

I found the 420e has the settings and technology I need to treat me the best. You can control and limit how it responds to Flow Limitation, you can control how it responds to Apnea and control how it responds to obstructive apnea over 10 cm and/or if CA's are a problem limit apnea response below that threshold. No other machine on the market other than the new Sandman Auto can you tweak those parameters which is what allowed that machine to work for me.

CA is not my primary disorder, I don't have any waxing or waning commonly found with CSR nor do I think it would remotely work in that case. If your disorder is primarily CA or CSDB you need a machine that can manipulate and stablize your breathing in order to eliminate the CA. With the 420e and how I have it set up, it effectively treats my OSA while leaving the CA's alone. I keep my Minimum pressure low, limit how it can respond to apnea and flow limitations and use a mask I know retains more CO2. I know from years of use and observing reports, my apnea threshold is 9, if I go over that at the wrong time I'll have all kinds of CA's. With the Silverlining reports I can see my results. I lowered Command on Apnea from 10 cm to 9.0 cm, disabled IFL1 which is command on Flow Limitation and it pretty much keeps CA's to non-existent or only 1 or 2 per night, I can live with that.

So will it work for you as backup? I cannot say without looking at your daily reports and knowing your SDB condition. You have to know what your current machine is doing, with a ST it will switch from Spontaneous mode to Timed backup mode in the presence of CA. 420e doesn't do anything of the sort it simply does a better job at differentiating the difference between obstructive and central events. For the latter it doesn't do anything where your ST might switch to Timed backup mode if it senses you have stopped breathing. If your machine is switching several times per night it may not work for you, it may if you spend majority of time in Spontaneous mode and don't have a loss to spontaneous respiratory drive. If you have any AHI info from your current machine that would be helpful, just understand there is no mode switching should you stop breathing as with your current machine, but I don't know how you have that set up as it can be in CPAP, BIPAP, S or S/T mode. If it is being run in S mode then you don't have any timed backup to revert to even if it is set up.

But if I was to choose any other non-ST machine for emergency use it would be the 420e or the new Sandman Auto, in fact I'd lean towards the Sandman, they surely have made improvements to it over the 420e. From seeing the reports I'd have to say they have only improved upon it while I still prefer the 420e's form factor.

My pressure is low usually under 10 cm, my titrated pressure was 9 cm 8 years ago still is today. But there are times the 420e reports going up as high as 14 cm to take care of hypopnea or chase a snore but not often.

Snoredog,

I am pretty new to this OSA stuff and have been having many troubles with the CPAP and with the sleep center being unable to figure out what is going on. Their solution has been turn up the machine and turn it down. The last time they wanted to set-up a machine for a couple of weeks that would record what my sleep paterns are. How ever reading through what you have wrote and the video from ResMed let me know that something else may be going on here.

I have had this machine for 3 months and at first it work great once everything has been set up correctly. Then I started to get more and more tired not know what was going on. I talked to the sleep center and they told me to turn it up which through me into severe restless legs. I was getting hardly no sleep at all so I stopped using the machine all together which helped for a while. However lately I am getting so tired I decide to use it again and I am now getting worse sleep then ever with the CPAP.

For the longest time I thought that maybe my chin was dropping during my sleep causing me to stop breathing. I tried many different things to stop that from happening using a couple of different chin straps at the same time which then I started to experience mouth venting through the lips. So switch to a full face with the chin strap and no luck. I have purchase and am waiting for it to arrive is the chin strap from Pur Sleep and hoping that will work or help.

But after reading your posting with this CO2 washout and the ResMed video I thought maybe I am suffering from something else. What you have described and the video it really seems to explain a lot of why maybe the sleep center was no to little help. However I never did do the sleep study with the machine that would record what was going on. I appreciate your input and suggestions and any other links that would educate me on this stuff. Thanks

[ozij]

I talked to the sleep center and they told me to turn it up which through me into severe restless legs.

OSA can keep a person from proper sleep. Once OSA is properly treated, you may find out you have other sleep disorders - e.g. restless legs. That does not mean the higher pressure caused your restless legs.

It is not clear who diagnose your restless legs, and if the diagnosis is correct - but its something you should have confirmed, and treated, by the professionals. Lowering your pressure to where you're having apneas, and no longer having restless legs is not such a good idea.

O.

[Snoredog]

Snoredog,

I am pretty new to this OSA stuff and have been having many troubles with the CPAP and with the sleep center being unable to figure out what is going on. Their solution has been turn up the machine and turn it down. The last time they wanted to set-up a machine for a couple of weeks that would record what my sleep paterns are. How ever reading through what you have wrote and the video from ResMed let me know that something else may be going on here.

I have had this machine for 3 months and at first it work great once everything has been set up correctly. Then I started to get more and more tired not know what was going on. I talked to the sleep center and they told me to turn it up which through me into severe restless legs. I was getting hardly no sleep at all so I stopped using the machine all together which helped for a while. However lately I am getting so tired I decide to use it again and I am now getting worse sleep then ever with the CPAP.

For the longest time I thought that maybe my chin was dropping during my sleep causing me to stop breathing. I tried many different things to stop that from happening using a couple of different chin straps at the same time which then I started to experience mouth venting through the lips. So switch to a full face with the chin strap and no luck. I have purchase and am waiting for it to arrive is the chin strap from Pur Sleep and hoping that will work or help.

But after reading your posting with this CO2 washout and the ResMed video I thought maybe I am suffering from something else. What you have described and the video it really seems to explain a lot of why maybe the sleep center was no to little help. However I never did do the sleep study with the machine that would record what was going on. I appreciate your input and suggestions and any other links that would educate me on this stuff. Thanks

Best thing to do is obtain a copy of your PSG that came from the Sleep Lab, since your doctor has already given you the findings, it should be easy to obtain that.

Read your PSG carefully including the summary findings. You have OSA which has arousals associated, you can have other disorders in addition to OSA such as PLMD, RLS and other parasomnias. Doctors many times overlook the latter and only address the Obstructive Apnea portion. This reduces the amount of arousals seen but may not do anything for those other events. Your PSG results should indicate "if" you have those other disorder/syndromes.

As for your pressure? I don't like to blindly increase pressure, I'd like to know what your current AHI is and determine from that if you need a pressure change. Your goal should be to get that value under <AHI=5. Once you get there you are effectively treated for OSA. If you remain tired then you look for those other items listed above contained on your PSG for contributing to the fatigue. Your machine may be reporting the AHI, just depends on what machine you have, we cannot answer that until we know exactly what machine you have and how it is setup to function.

You currently show a S8 compact CPAP machine. Unfortunately it does not supply sleep data such as AI, HI and AHI like the Elite version machine. So without that info available on your machine, you need to rely on your PSG titration and how they found your prescribed pressure.

What is the pressure you were originally set at from the PSG?
and what are you at now?
do you wake during the night for no reason?
is your only complaint the fatigue?
any difficulties falling asleep?

[epo]

Snoredog & O


What is the pressure you were originally set at from the PSG?....10
and what are you at now?....10 right now I figured out how to turn it back down.
do you wake during the night for no reason?....only when I don't use the CPAP
is your only complaint the fatigue?.....Very tired as if I was up all night.
any difficulties falling asleep?

....I do take benadryl and melatonin to help me fall asleep. If I don't I can be up for hours trying to fall asleep.

They told me I quit breathing 23 time per hour. They set me at 10 in the beginning and I slept good once I was used to the machine and mask. Then shortly after that I started to get very tired. I went back to the doctors and didn't get a copy of my PSG but this is what they told me. "you are going to be tricky to figure out". Anything under ten I started to experience OSA and low oxygen. Anything above 10 they said my legs where kick quite a bit. I did experience that quite a bit when they switched me up to 11 plus I was experienceing a very irritating feeling in my legs. So I turned it back down to ten where I can't get sleep.

I have not gone back to the doctors only bacause I was getting fustrated with them in what seemed like they where geussing at their tries. I will go back and try it again. I think the biggest thing with the doctors are they have the PA's and they talk to you then convey what I said to the doctor and then the PA comes back to tell me what the doctors said. That is fustrating. I would rather just deal with the doctor. I will also fill that prescription the doctor wanted for the machine that records what is going on in the sleep. The doctor wanted that test done with the machine set at 11 which drove me crazy.

Thanks for all your input and I hope we can talk more later as we go along. Please feel free to offer any more advice or info. Also I am new to this and still learning all the accronyms.

epo

[stcrim]

I know this is an old thread but couldn't you avoid a reduction in Co2 by restricting your exhale. For example there is a commercial product called TheraVent that restricts the exhale for snoring. They also have a prescription item called Provent.. You could also use waterproof tape and punch 3.5 or 4 mm holes in them to cover each nostril.

Since carbon dioxide promotes nitric oxide which opens air passages and dilates arteries and veins it would seem that having the correct amount would be important.

Seems like there is more to Co2 than meets the eye.

I gave up using just a TheraVent for apnea and am now on a RemStar Pro with C-Flex+ with an AirFit P10 but also have several nasal masks that I switch around. Nothing is more comfortable that the Airfit P10 but I do have to tape my mouth shut and even then can get blowouts. The machine finally settled my pressure at 11.5 but I have as many as 20 to 25 CA's per night.

Since I am new to the APAP I have not tried restricting the exhale as yet to reduce CA's

[Kayak]

Hello everyone,
Sorry for using this old thread, but I believe the issue I have is related.
I've been treating my OSA very successfully (from AHI of +120 to the current average of 1.5), using an Autoset (Resmed), and a vented F&P Eson nasal mask. Credit for all this is due to... someone on another forum. I think he's here too

My pressure settings seem adequate (13/20) and leaks are well within tolerance. I use EPR set to 3.

As my AHI was dropping and as my sleep was improving, I noticed that an old friend... RLS... came back to visit. Nothing dramatic, just a 20 minute pause almost every night, and interestingly enough, ALWAYS an hour and a half after going to sleep... I've read elsewhere that RLS can be associated with hyper/hypocapnia. As this topic clearly suggests... CPAP usage combined with some settings and some masks clearly influences the level of CO2 present in our bloodstream.

The influence of hyper/hypocapnia over RLS is very disputed, so I prefer not to debate that... My question is: How does Resmed's EPR setting influence CO2 washout? Does a high EPR setting increase the washout, or is it the contrary? Thanks

[palerider]

The influence of hyper/hypocapnia over RLS is very disputed, so I prefer not to debate that... My question is: How does Resmed's EPR setting influence CO2 washout? Does a high EPR setting increase the washout, or is it the contrary? Thanks

yes, EPR, like all bilevel treatment, increases ventilation, which means you have a higher tidal volume, which means there's more co2 blowoff. (I say blowoff to mean 'removal of co2 from blood, vs washout which at least to me, implies clearance of co2 from the mask.)

a fairly small percentage of people are sensitive to even a small reduction in co2 and EPR can cause more central apneas.

whether that hypocapnia can exacerbate RLS is something for someone else to comment on, since that's outside my experience.

[Kayak]

Thank you for your answers, Palerider. I find the coincidence very odd... I'm deeeeep in severe OSA for a long period, but RLS disappears (there's no way you can sleep through this, unless you're in a coma). I get treated by CPAP, and it comes back. There has to be a connection, somehow.

[palerider]

Thank you for your answers, Palerider. I find the coincidence very odd... I'm deeeeep in severe OSA for a long period, but RLS disappears (there's no way you can sleep through this, unless you're in a coma). I get treated by CPAP, and it comes back. There has to be a connection, somehow.

perhaps kayak, hopefully someone else with more experience in RLS and PLMD will chime in.