ASV: Diff algorithms appear to offer complimentray benefits.

[dsm]

This is of general interest in how different brands of machine can give different results at different times.

For well over 8 months (early April 2008 to end 2008) I was using a Bipap Auto SV - started a thread here about the experience & in general waxed lyrical about what a great night's sleep I was getting from the machine (called it my 'Dream Machine'). I also had a Vpap Adapt SV that I found very hard to use & initially in about 5 attempts to use it, lasted max 3 nights before reverting to the Bipap Auto SV. Then I swapped from using an Ultra MIrage F/F to a Quattro F/F (better bridge adjustment & seal) & found I could persevere with the Vpap Adapt SV if I really tried but always loved the deep restful nights the Bipap Auto SV offered.

At end of 2008 & after 8+ months excellent results from the Bipap I hit a spell where daytime sleepiness was returing, on a hunch I switched to the Vpap Adapt SV & all came right. It is a harder machine to sleep with, the nights with it seem to result in lighter sleep, but the days were always ok. That period paved the way for lots of serious exercise & a significant weight loss (Sept 08 weighed 97 KG & today 84 KG) - then winter hit us here in Sydney & after approx 5 months the sleep with the Vpap Adapt SV seemed to be unsatisfying & just couldn't quite figure out why, but on a hunch swapped back to the Bipap Auto SV. Back to great very nice nights sleeps & good days. Then it dawned on me that the probable difference between the 2 machines was related to sinus congestion. The Bipap Auto SV is *very* tolerant of slow breathing (very).

As winter hit, the sinuses became a real problem (went to ENT who now has me lined up for a good nasal reaming & tonsillectomy etc: ). Then I remembered that I had switched to the Vpap SV just as winter ended & sinuses have been very good for the past 5 months.

At different times different folk have raised this matter of changed therapy as the seasons change & it has always seemed a fair line of thinking. Based on this last episode for me, am thinking it is more than probable that winter / summer can change therapy markedly for some of us who have nasal respiration issues.

Just to emphasize how good a nights sleep the Bipap Auto SV is providing, I have attached the past 2 nights data - the point is that the pressure support is operating all through the night & approaching 20 CMs often. But the AHI scores are negligible. What I see is a machine doing a wonderful job of 'normalizing' respiration & archiving excellent results.

http://www.internetage.ws/cpapdata/dsm- ... 0may09.pdf Fri 29th May
http://www.internetage.ws/cpapdata/dsm- ... 1may09.pdf Sat 30th May
(am willing to bet that the tiny number of AIs scored were *all* centrals - NO OSA events scored at all - just look at the pressure being applied to clear them (pressure + cycling) re cycling, note that every apnea scored has a matching event indicating the machine took control of breathing rate & initiated cycling, that is forced breathing cycles & added significant pressure support to reinforce them). Also, am pretty certain most of those scored AIs were at times I had turned over in the night. If so, why do we move in the night (what triggered it), well for 1, are you the only person in your bed & if not does your partner *ever* disturb you mildly of otherwise due to their own sleep irregularities & patterns - just think how many of us here chase the elusive 0 AIs & 0 HIs when all along they are caused by someone else ).

The summary for me, is how each brand's algorithms does work differently but how for me the two complement each other based on changes in the seasons. With that in mind am looking to buying a Weinmann SOMNOvent CR (ASV) machine to compare it as well. On paper it appears to have the most sophisticated mix of algorithms of any ASV or AUTO or Bilevel, on the market. It uses Auto algorithms to monitor & adjust epap, it uses OPP to detect obstructive apneas from central apneas, it uses a very novel form of Servo Ventilation pressure support to 'normalize' any irregular breathing patterns (CompSA, Mixed SA, CSA etc: ).

As said, on paper it seems they have bundled the most advanced forms of Auto, Bilevel & Servo Ventilation into one machine. Theoretically it does the lot !. So, will look into evaluating one. Am wondering if this is an early example of a machine that can deliver all effective modes of therapy in the one unit. This is where I believe the industry may be heading.

DSM

[billbolton]

At different times different folk have raised this matter of changed therapy as the seasons change & it has always seemed a fair line of thinking. Based on this last episode for me, am thinking it is more than probable that winter / summer can change therapy markedly for some of us who have nasal respiration issues.

I don't have any particular nasal respiration issues, but I do notice some difference in my AHI numbers between winter and summer in Sydney (or should I say, almost-wet-season and almost-dry-season).

It used to be more noticeable but since I started using a heated hose in winter it has dropped down to a point where in summer my weekly average AHI is usually just under 3.0 with often nights of 0 AI, while in winter my weekly average AHI usually just over 3.0 and fewer nights with 0 AI. However for me this is not concerning and I don't notice any difference in my daytime alertness/well being.

Cheers,

Bill

[dsm]

At different times different folk have raised this matter of changed therapy as the seasons change & it has always seemed a fair line of thinking. Based on this last episode for me, am thinking it is more than probable that winter / summer can change therapy markedly for some of us who have nasal respiration issues.

I don't have any particular nasal respiration issues, but I do notice some difference in my AHI numbers between winter and summer in Sydney (or should I say, almost-wet-season and almost-dry-season).

It used to be more noticeable but since I started using a heated hose in winter it has dropped down to a point where in summer my weekly average AHI is usually just under 3.0 with often nights of 0 AI, while in winter my weekly average AHI usually just over 3.0 and fewer nights with 0 AI. However for me this is not concerning and I don't notice any difference in my daytime alertness/well being.

Cheers,

Bill

Bill,

I am sure getting a lot of rainout at the moment - that was happening on both machines & even when heat turned way down. But humidity is super high at the moment.

I do find with the Bipap Auto SV, that I have a stronger desire to stay snugly in bed ? - I noticed this last year when on it.

DSM

[dsm]

Just got the price in $AUS for the Weinmann SOMNOvent CR ASV machine.
At $AUD 7,000 it goes onto my fantasy list.

Will stick with the existing units

DSM

[KevinDL]

For comparison, how much are the Bipap AutoSV and Vpap Adapt SV in $AUS?

Thanks,

Kevin

Just got the price in $AUS for the Weinmann SOMNOvent CR ASV machine.
At $AUD 7,000 it goes onto my fantasy list.

Will stick with the existing units

DSM

[dsm]

Well, that is where we can get lucky - I bought my Bipap Auto SV as new from cpapauctions (2 hrs use on it) for $US2,300 (IIRC) - but here in Aust they sell for $AUD 4,500. The Vpap Adapt SV can be bought here today for $AUD 3,600 but list is $AUD 3,900 - I got mine (version 1 model) from cpapauctions for $US 750 (have also seen others sell this cheaply there).

So now I have to wait 2 years for some used SOMNOvent CRs to show up on scheepapauchtungs.com.de

What I do find quite odd here in Aust is the current pricing of Resmed vpaps. This is from a local website & makes little sense to me ...


https://www.cpap.com.au/resmed.htm#8

Vpap III STA -- $AUD $8,500 (this is a hospital use version)
Vpap Adapt -- $AUD 3,999 (but typically avail for $3,600)
Vpap IV S -- $AUD 3,500 (S8 case)
Vpap IV S/T -- $AUD 6,900 (S8 case) -- This makes no sense compared to the Vpap Adapt price

Am left believing the Vpap Adapt SV will be replaced shortly, possibly with an S8 case based unit (purely me speculating without any tangible evidence (just a hunch)). I might even suggest it gets dropped from the line & replaced by a different S8 based Vpap with extended features. I am sure the ASV won't get dropped altogether but think the current Vpap Adapt SV will be remembered as an experimental machine that paved way way for newer self setting systems that require the minimum of doctor/lab set up & offer the maximum self adjustment & therapy output (actually, this is me doing some wishful thinking ).

I know that if I were a manufacturer looking to establish a bigger market, I'd be out to design a self setting machine that self adjusts to the broadest base of cpap needs (OSA, SA, Periodic Breathing (CompSA, MixedSA, CSR)). The SOMONOvent CR may be on that path. My bet though, is Resmed will make the next major move in this area. They have all the bits needed plus several years real world experience gathered from Vpap Adapt SV deployments. Respironics lack a new blower like Resmed pioneered in the Vpap Adapt SV - a blower of that caliber is needed to make such a jump. Respironics still use the magic but very expensive 'air valve' to control air flow in their Bipap Auto SV & top of the range special Bipaps. They are phasing them out (just too expensive to manufacture).

DSM

[dsm]

Some further thinking out loud re ASV machines.

From what I gather the SOMNOvent CR *doesn't* use proximal sensing & neither does the Bipap Auto SV but both machines have FDA certification (Weinmann is currently conducting a 6 month trial of the SOMNOvent CR).

So the Vpap Adapt SV approach of using proximal sensing line (that is a small external air line that attaches outside the main air hose & ends just at the mask & reports back to the internal sensors, the real time pressure at the mask), is apparently not absolutely essential to delivering Servo Ventilation. But it appears to be what makes the Vpap Adapt SV so precise in its control (e.g. compared to the Bipap Auto SV).

At a guess, I would say Resmed will drop it in favour of remote sensing (that is the machine takes an educated guess at what is happening at the mask 6 foot away, which is what Weinmann & Respironics do & manage to get by). The proximal sensing line always allowed the Vpap Adapt SV to know exactly what was happening at the mask, but the point is, is it really that important. It seems the machines can get it wrong without that causing any apparent problems to the patient. But It also seems to me that if the machine is sold as addressing CSR (Cheynes-Stokes Respiration) in patients with CHF (Congestive Heart Failure), the machine can't afford to get it wrong as there is always the potential for the manufacturer to be blamed for a CHF patients death & get hit with individual or class-action lawsuits. No manufacturer needs that.

DSM

[Velbor]

At different times different folk have raised this matter of changed therapy as the seasons change & it has always seemed a fair line of thinking. Based on this last episode for me, am thinking it is more than probable that winter / summer can change therapy markedly for some of us who have nasal respiration issues.

In the process of responding to another thread, I just found the following article which made me think of your comment:

Nasopharyngeal symptoms in patients with obstructive sleep apnea syndrome : Effect of nasal CPAP treatment

While not relevant to your observations about different machine algorithms, they did find nasal problems worse in winter (in Finland) than in summer, perhaps suggesting that dryness may be more of a contributing factor than seasonal allergies.

[dsm]

Vebor,

Thanks for the link - will work my way through it.

But here is another oddity - I haven't mentioned this before as I just couldn't be sure the observation was
good enough to state publicly, but, ...

Over the past few years, I have experienced leg cramps mostly in the lower legs calf area. I at first
attributed these to two things - one being jogging & exercise (so made sure I did relaxing exercises
with legs) & the other as possibly a side effect of red wine (I know what gout is like & it isn't that).

I also began taking regular magnesium tablets & more recently magnesium & calcium. These didn't really
seem to make any big difference. I also went to my dcotor who basically said, there was no certainty what
caused nocturnal cramping. He gave me a prescription for quinine & although I have had them ready to take
for a week & am exercising daily (30 km each day on my bike). Since swapping back to the Bipap Auto SV
the tendency to cramp seems to have gone away & the quinine is sitting there unused.

What I had observed last year but was not willing to publish, was that when I was on the Bipap Auto SV, I
hardly had any issues with cramping. But when I went onto the Vpap Adapt SV the issues returned. Now
having just gone back to the Bipap Auto SV, the cramps seem to have diminished (had none at all this week).

I was reluctant to bring up the experience because it seemed far to unlikely that changing the type of
ventilation, could be connected to leg cramps. So I sat on this suspicion until this week & when I swapped
machines I said to my wife, "I wonder if the cramps will go away" & thus far they have.

My next line of thinking was what on earth difference in ventilation could affect cramping, the best guess
I can come up with is the level of CO2 in the blood. But this is a wild shot & doesn't seem related but am
wondering if there is some link.

If anyone has any thoughts or theories am all ears !. (am still thinking that changing machines should not
be the cause).

DSM

Just wanted to add, that am known to be sensitive to cold & heat in that in summer I will usually keep a
woolen pullover on my back whereas in winter am not so bothered. I am sure I read somewhere that a side
effect of CO2 imbalance including being a mouth-breather & having essentially a UARS condition caused
by restricted airflow through the nasal passages, is all tied together - thus am wondering if the cramps
are another part of it all ?

#3 Just thinking further, the Vpap Adapt SV may wash out less CO2 than the Bipap Auto SV ??? - will think
on this some more. As mentioned, I find I don't want to get up quite as enthusiastically when using the
Bipap Auto SV as the sleep is deeper & much cosier. But, with the Vpap Adapt SV, sleep is much lighter
and getting up is easy.

[Velbor]

Compliments of ozij, here is the full text version of the article I cited:

http://content.karger.com/ProdukteDB/pr ... =29354.pdf

[jnk]

Compliments of ozij, here is the full text version of the article I cited:

http://content.karger.com/ProdukteDB/pr ... =29354.pdf

Many thanks for that link Velbor and ozij!That was very helpful to me.

The weird thing I'm experiencing right now is that as grass pollen has started flying around here in Brooklyn, my nose has been too stopped up to feel comfortable starting out the night at 8 cm EPAP, so I've had to raise my minimum EPAP to 10 cm to feel comfortable breathing out as I start out the night. My numbers are fine starting lower; I just feel like I can't breath out against the pressure with anything less that 9.5 or 10 cm. Odd.

jeff

[dsm]

Velbor, (& Ozij) yes very interesting & provides a pretty clear answer to the summer/winter effect.

Re the cramps - again last night none happened but what I was aware of, is it seems to happen in the 2am - 4am period
of the night. Rarely at the start of the night & usually gone in the hour before wake up.

The pattern I am aware of is,

wake
do a big stretch (straighten legs right out)
cramp strikes (last night there was a hint of cramping but it went away before a cramp happened)

What ever causes it, I am usually aware of when it is going to happen. It is probable that these coincide with
central apneas as shown in the charts listed earlier.

DSM