The second graph shows, in liters per minute, maximum leak (I postulate that 120 L/m is the maximum the machine can record, that's basically off the face), the average leak, and the 90% leak.

Is the 90% figure the mysterious one to you?  That one represents the 90th percentile, or put another way, it is the rate at which 90% of the data is at or below it and 10% of the data is above it.

So while you experienced leaks at or in excess of 120 L/m, 90% of the leaks were hovering at or below 40-60 L/m points as shown in the graph (more or less on specific days).

Hope that helps.

IMO the Encore software gives a better picture than Encore Analyzer does.  The Encore Analyzer software is very nice especially for its price   and gives broad graphs over large periods of time, certainly useful.  For specifics you need the hour-by-hour charting provided in Encore Viewer or Encore Pro.

Blessings,
--pseudonym

Thanks for your interpretations of this, Pseudonym. Is 40-60 L/m somthng to be concerned about?

I sure would like to learn more about interpreting Encore Pro - any good books or websites you know of?


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Respironics Remstar M Series CPAP
Respironics ComfortGel Nasal Mask

Probably so.  It depends greatly on your mask.  Since you are using a Respironics machine finding out if your leak rate is excessive is much simpler than with a Resmed machine.  (Resmed tries to be 'helpful' by assuming a portion of the leak is normal, and displaying the remainder.  This is great if you are using certain Resmed masks that the machine knows the details about.  Otherwise it is quite 'unhelpful' and makes the job of calculating leak rate a little more complex.)

So for you, you need to arm yourself with two pieces of information.  One you have from the machine, and the other you need to get from Respironics spec sheet for your mask.

1.  Look at your 90th percentile figures from your Encore software (don't use Encore Analyzer) and see which figure seems to be the most consistent.  This figure should be L/m (liters per minute).

2.  Get the spec sheet from Respironics for your mask, it will have a chart or table of expected ('normal') port exhaust leak rate for your pressure.  The leak is different at different pressures so you need to look up the figure.

You mentioned in this post a Comfortgel Nasal mask.  I looked that up on the Respironics web site, if this is your mask the page is here:
http://comfortgel.respironics.com/

However they make it harder to find the expected leak rate.  It is not on the spec sheet listed on that page, it is in their resource library in the User Guide for the ComfortGel:
http://global.respironics.com/UserGuides/1033258b00ComfortGel.pdf

{<rant> sigh.  Why do they make us hunt for information? </rant>}

If that is NOT your mask you must look up the correct mask in the Respironics library and find the right leak rate for your pressure.  Each mask has a different expected leak rate, and can be significantly different from other masks.  Don't use one that seems "close".

1.  Near the bottom left of the first page is a little graph.  What is your pressure?  Look at the intersection on the chart and that is your expected leak in liters per minute.  

2.  Take that expected leak figure from step 1, and multiply it by .15 (e.g. 15%).  Also multiply it by .1 (e.g. 10%).  As a general rule of thumb, 10% of expected is allowable.  Some docs think 15% of expected is OK, hence calculating both figures.

3.  Take the expected leak figure from step 1 and subtract it from the 90th percentile leak you chose from your Encore pro software, as typical for you.  This is the excess leak you experience regularly.

How does that excess leak figure compare to the allowed amounts you determined in step 2?  

If it is not at or below the 15% figure, you are definitely experiencing too much leak (probably you are mouth breathing).  If it is between the 10% and 15% figures you are still experiencing too much leak according to many docs.  

Blessings,
--pseudonym

Thankyou for all of the above. I can't for the life of me though find where in Encore Pro there is info about leakage rate - do I need to look in one of the three reports which are produced by the clicking the link 'Reports' on the left hand side of the Encore Pro home page?


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Respironics Remstar M Series CPAP
Respironics ComfortGel Nasal Mask

If you consult the Encore Pro help, while it is not overly detailed, you should be able to find and use all the features of the program.  In particular the detailed reports are available by choosing an upload date range.

Blessings,
--pseudonym

Hi, Richard.
I'm going to be a dissenter on this one. When I used a full mask, I had dry mouth. Now that I have a nasal mask, I still have a dry mouth. If it happens after I fall asleep, it doesn't bother me. But if it gets dry enough beforehand, I'll get a tickle in my throat, take a sip of water, and try to settle down again This is only mildly helped by the humidifier. I don't open my mouth in my sleep; I wouldn't automatically assume that you are. And you might want to try some of the oral products (sprays or gels) made for dry mouth, as they're also helpful.


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RemStar Plus w/C-Flex. New Breeze nasal pillow mask. Pressure: 9.

@jed You're absolutely correct, he should not *assume* he is mouth-breathing.  Dry mouth can be caused by many things as you said.

That's why I have asked him to figure out the leak.  If he is using a nasal mask and it is leaking excessively, the *most likely* cause is mouth breathing unless he knows the mask itself is really leaking (probably would know that for certain only if a partner told him, or it woke him up).

Excessive leaks with a full face mask can also cause dry mouth, so looking for leak problems is still a good idea.

If leaking has been fully resolved, and the reported leak is well within specifications for the mask + some 10% or so, then other causes must be sought.

Blessings,
--pseudonym

Distilled water can range in ph from about 5.6 to 7 when purchased.  However, it readily turns acid when exposed to air.  The humidification system of most CPAP machines pass air through the water chamber.  This can turn the distilled water to a mildly strong acid of about 3.5 ph.  Using distilled water, I experienced a burning dry sensation in my nose and throat.  Also a strange taste in my mouth.

I've been experiencing dry mouth since I started using CPAP nearly three months ago and some nights are worse than others. I am a mouth breather and use a ResMed S8 Autoset Vantage with a Quattro full face mask. After the first week, I turned the heat and humidity setting to max and and some nights are fine while others (like last night) I wake up feeling like my mouth slept in the desert! I was instructed to use distilled water and the few nights I used tap water I could taste the difference. I experienced dry mouth either way though. Should I try other water out there (spring, purified, etc...)?

The type of water you use in the humidifier is not going to do anything for your dry mouth problem.  You are probably experiencing leaks at night that you are not aware of. This can happen when the ff mask does not fit well.  I was on a lot of meds when I first started cpap, and my dry mouth problem was so bad I almost lost a couple of teeth because of it.  The mask would slip on me in the middle of the night, and I would sleep right through it. I use a resmed elite , and found out how to access the data on my machine, and I was leaking big time.  I have reduced my meds quite a bit now, so I notice when the mask slips on me. I solved that problem by using silicone ear plugs on the bottom of the mask. I still have problems with leaks, but not nearly as much as before, and my dry mouth problems are minimal if at all.  Virginia


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Resmed elite , 17, mirage quattro ff . 25 + years of untreated OSA

offevets wrote:

Distilled water can range in ph from about 5.6 to 7 when purchased.  However, it readily turns acid when exposed to air.  The humidification system of most CPAP machines pass air through the water chamber.  This can turn the distilled water to a mildly strong acid of about 3.5 ph.

Offevets, can you point me to URLs on the 'net, from sources you would consider trusted, that illustrate how the water can go to 3.5 ph?  I've not run across any information like this and would really appreciate some links.  Thanks in advance!

Blessings,
--pseudonym

To go back to an earlier point in the thread, I still simply cannot see anywhere in Encore Pro where leak rate refers to. This may be because my PC is no longer recognisng my card reader for some reason and is using previously downloaded data. As far as I can make out from Encore Pro Analyser, the average 90th percentile leak rate is about 50 l/m but is often above 60 and sometimes 70 or even 80.

Luckily I am off to the clinic on Thursday. I will ask them then about leakage, and whether the pressure is set high enough.


_________________
Respironics Remstar M Series CPAP
Respironics ComfortGel Nasal Mask

And judging by the Respironics graph for pressure v leak rate, for my mask,  which I have downloaded, it should be about 25 L/m.

So to use Pseudonym's procedure:

Step 1: Expected leak rate about 25 L/m

Step 2: 15% of this figure is 3.75 L/m, 10% is 2.5 L/m

Step 3: (Very) approximate 90th percentile leak is 50 L/m, thus excess leak is 25 L/m

Clearly the excess leak is way over  and EP Analyser shows some large leaks as well. So combine that with compliance averaging three hours per night and I think we see why I am not making huge strides.


_________________
Respironics Remstar M Series CPAP
Respironics ComfortGel Nasal Mask

offevets wrote:

Distilled water can range in ph from about 5.6 to 7 when purchased. However, it readily turns acid when exposed to air. The humidification system of most CPAP machines pass air through the water chamber. This can turn the distilled water to a mildly strong acid of about 3.5 ph.

This smells of urban legend.  Unless you can point to a scientific study proving this to be true, I call BS.