Anyone familiar with Servo-Ventilator from Respironics?

Hi,

I'm asking this for my best friend's dad, not me... he was put on a Respironics SV because of his central sleep apneas, and his doctor seems to think he is doing great. That said, I have my doubts because although his AHI is low at 4.4, his report indicates the following leak statistics:

Average Max Leak -- 148.0
Average 90% Leak -- 91.9
Average Leak -- 78.8
Average Large Leak -- 4 hrs. 46 mins. 44 secs.

Those leak figures seem off the charts for me, but perhaps Servo ventilation is different, which is why his doctor said everything is fine?

His mask is a Respironics ComfortGel Full Face Mask.

Can anyone shed light on this for us?

It all depends on his pressure, but that leak is way out of whack, any AHI seen would have to be skewed from it.

You are correct, that leak rate is out of the ballpark and needs to be addressed. He's either mouth breathing or the tank coupler is missing/leaking on the humidifier.

If his pressure is 20 or less, it should be down below 75 L/m at all times, better around 50L/m with a full face mask, even lower for a nasal in the 28 to 40 range depending on pressure.

Snoredog,

His Avg Peak IPAP is 11.0; his EPAP is around 7.0. How does that change things?

Mike

Mike,

Here is an example of a night on Bipap SV where the leak was high but didn't cause any detrimental effects.
http://www.internetage.ws/cpapdata/dsm- ... d_leak.pdf

But I have another chart with a far higher leak rate where for some reason the machine kept leaking each night despite me replacing various parts (hose, H/H seal etc: ) and after 3+ nights of heavy leaks I was starting to fall asleep at work in the middle of the day.

But the AHI numbers looked fine. So I learned from that episode that although a user can think things are ok, they can be deteriorating rapidly.

My advice is 'he must get that leak sorted out'

Good luck

DSM

Doug:

Did you ever figure out the cause of that large leak?

Large Leak
4 hrs. 34 mins.
67.6% of Night

Looks like the SV also uses the 75L/m limit like their other machines for determining Large Leak (indicated by that solid black bar above the leak graph).

His Avg Peak IPAP is 11.0; his EPAP is around 7.0. How does that change things?

Mike

That makes the leak rate you indicated above even worse. He should be under 35 at those pressures, if a FF mask, up to 50 L/m maximum.

Is he taking off his mask BEFORE shutting the machine off?
The machines have an option called "Auto Off", which is supposed to shut the machine down after taking off the mask, but it's a REALLY DUMB feature. And, for those who use it, it will really screw up the statistics.

The user should shut the machine off BEFORE taking the mask off.

Den

Wulfman wrote:Is he taking off his mask BEFORE shutting the machine off?
The machines have an option called "Auto Off", which is supposed to shut the machine down after taking off the mask, but it's a REALLY DUMB feature. And, for those who use it, it will really screw up the statistics.

The user should shut the machine off BEFORE taking the mask off.

Den

The Adapt SV doesn't have that feature.

Snoredog wrote:

Wulfman wrote:Is he taking off his mask BEFORE shutting the machine off?
The machines have an option called "Auto Off", which is supposed to shut the machine down after taking off the mask, but it's a REALLY DUMB feature. And, for those who use it, it will really screw up the statistics.

The user should shut the machine off BEFORE taking the mask off.

Den

The Adapt SV doesn't have that feature.

OK.....thanks.

Den

Doug,

I'm confused because the report you sent looks like the leak is terrible/out of control high, but you are saying that it was not "detrimental." This is exactly what is confusing me. Here, the leak looks off the charts terrible, but he seems to feel great and the doctors are telling him everything is great. Should we still be worried?

Mike

miggity wrote:His mask is a Respironics ComfortGel Full Face Mask.

Snoredog wrote:He's either mouth breathing or the tank coupler is missing/leaking on the humidifier.

miggity, it wouldn't matter if he's mouth breathing since he's wearing a Full Face mask, as you mentioned in your original post. Also, there are other possibilities for the high leak than a problem with the "tank coupler", although every connection should be checked, all the way from mask to machine. Be sure the little O2 ports on the mask are plugged.

More likely it's the mask leaking badly around the cushion, or the mask getting dislodged. Also, I'd wonder if the man is sometimes taking his mask off during the night, either deliberately or in his sleep.

miggity wrote:Here, the leak looks off the charts terrible, but he seems to feel great and the doctors are telling him everything is great. Should we still be worried?

I'd be worried about that high leak rate. The doctors are likely going by what the man says, so if he's telling them he feels "great".....

It's possible to think you're feeling "great" simply because you're feeling "better." I'd go to work on figuring out where the leaks are coming from, even if it meant enlisting the aid of a night owl to sit up all night with the man, listening for massive whooshing leak sounds escaping around the mask cushion. Of course, maybe he really is doing great and feeling great despite the leaks. Me... I'd still try to lower that leak rate.

Mike,
I have a set of worse charts than that (still trying to find them). But the machine seems to be able to cope with some leak but then
if the leak gets really bad therapy goes downhill over a few days.

There was a time I proudly claimed the Bipap SV was leak tolerant as I have many occasions where the black bars showed but I always felt fine. Then I hade a period of a week where every night the leak was massive & that knocked me for six (I even went to see my doc & did a blood test - all ok).

So what I believe now is that even the Bipap SV can't work around big leaks even though the data looks like it is.

SnoreDog
I never did actually find with any certainty what cause the week of leaks. I think though it was having the mask straps set too loose.

RestedGal
I agree (as per above) that there are times when we can think we are ok but the therapy is on a downward slide. My recent experience with constant leaks that I just could not nail down, has convinced me now that leaks are bad no mater what & need to be sorted out.

DSM

All,

Thanks for your thoughful guidance. I thought that there might be something about SV that set it apart from what I know about more standard devices like CPAP, but it seems that's not the case. I will disregard the doctor's conclusion that everything is ok, and his feeling that he is doing fine, and investigate the leak further. Could very well be his beard, which can't help the full face mask fit...

Mike

Average Large Leak -- 4 hrs. 46 mins. 44 secs.. That's crazy.

O.