Respironics total leaks - is there a "line in the sand" like ResMed?

Philips Respironics reports total leak - intentional and unintentional. I don't recall where I heard it, but for some reason the leak level of 50 to 60 liters/minute is stuck in my head.

I figure since I probably heard this from a sleep technician or physician at some point, that these are very conservative values. My guess is that the machine can compensate up to 70-80 l/m but that is just a guess.

I just started testing out a PR System One AVAPS the last two nights. In reviewing the data there are no abnormal drops in pressure or alterations in respiratory data like tidal volume/respiratory rate, etc,. so I assume the machine is compensating for any unintentional leaks just fine. To my surprise Sleepy Head seems to be able to read the data pretty well! Although Direct View software tends to be more helpful for this specific machine.

One interesting thing: using ResMed I always have an AHI of zero (I use bi-level as a ventilator, I don't have sleep apnea). With the PR System One, a few hypopneas have been recorded on both nights. Less on the second night, since I raised my target average tidal volume. Makes sense since hypopneas are shallow breaths.

So you don't have either Obstructive or Central Sleep Apnea.

This begs the question, "For what condition(s) are you using a ventilator?"

At least when treating Obstructive Sleep Apnea, leaks are a problem only if they annoy you (or your bed partner) or if they exceed the machine's ability to compensate.

encore basic will flag what is considered large leaks. There is no definite definition of large leak with respironics. it really depends on how long you are at a given leak pressure. up or down to 40 or 60 may not trigger it but being up there constantly would trigger it. you really need to get encore basic and see for yourself to understand it.

to compare with resmed, resmed has a 24L red line. but in resmed you enter your mask in the system and it subtracts that as an unintentional leak. lets say for instance that you exhale 40L from your mask. your total leak would have to be 64 for the machine to show up as 24. in other words resmed shows intentional out the side of the mask leaks as a number, not the unintentional normal breathing that is subtracted. respironics shows total leaks combined. a bit like apples and oranges and meant to be confusing.

raisedfist wrote: ↑

Fri Jul 06, 2018 6:58 am

Philips Respironics reports total leak - intentional and unintentional. I don't recall where I heard it, but for some reason the leak level of 50 to 60 liters/minute is stuck in my head.

Pugsy often mentions a number, just because people like to have something... but, no, there's no set number.

Respironics machines aren't smart enough to figure out what the *excess* leak is, so they just report total, since that's simple to figure out. And since the vent rate in any mask varies with pressure, the unacceptable amount of leak will *also* vary with pressure.

If you were on a fixed pressure machine, you could look at your masks expected vent rate and add 25-30 lpm to that, and maybe get a reasonable resmed like excess rate to try and stay under... however it wouldn't be accurate, because what Resmed considers excessive, and what Respironics considers excessive aren't the same.

I recommend just turning off the 'flag leaks over...' setting in sleepyhead, and just let the LL flags that respironics machines create be your guide.

raisedfist wrote: ↑

Fri Jul 06, 2018 6:58 am

I figure since I probably heard this from a sleep technician or physician at some point, that these are very conservative values. My guess is that the machine can compensate up to 70-80 l/m but that is just a guess.

Oh, at least, at 20cm pressure, since most masks vent around 50lpm at 20cm pressure. but, that would be a ridiculous leak at 4cm pressure.

raisedfist wrote: ↑

Fri Jul 06, 2018 6:58 am

One interesting thing: using ResMed I always have an AHI of zero (I use bi-level as a ventilator, I don't have sleep apnea). With the PR System One, a few hypopneas have been recorded on both nights. Less on the second night, since I raised my target average tidal volume. Makes sense since hypopneas are shallow breaths.

Perhaps because Resmeds are more responsive.

. wrote: ↑

Fri Jul 06, 2018 7:30 am

So you don't have either Obstructive or Central Sleep Apnea.

This begs the question, "For what condition(s) are you using a ventilator?"

None of your business.

And the nose pokes in again.
Also NOT RELEVANT to the topic of this thread.
And not an answer.