Feedback on first week of SleepyHead/new S9?

Hello,

I have now used SleepyHead and all of my new equipment (posted below, I hope) for one week. Until now, I have never had software to give me all of these statistics--previously, I'd go to my doctor, his PA or he would tell me everything looked fine, and I barely knew what the data meant on the summary they'd hand me.

I was diagnosed with mild sleep apnea (OSA, 12 events per hour; all positional, during the time I sleep on my back) two years ago. At that time, I had no central apnea. The doctor predicted from examining me that it was very unlikely that I would have sleep apnea, as my airway on examination was "wide open" and my BMI is just over 18. Obviously, to his surprise, I do have it.

(I went to the doctor because I was snoring and preventing my husband from sleeping the night before he ran the NYC Marathon. The doctor loved that story.)

During the past two years until recently, I was using completely different equipment (Respironics System One with integrated humidifier) which was giving me a cold nose and a lot of water in the hose and nasal pillows. I was also using Swift LT for her, which I liked, and the new Swift FX is even more comfortable (if I have to do this!). I had several months of noncompliance because of the cold nose and wet tubing (turned out the Respironics integrated humidifier wasn't heating at all).

The new machine with the heated tubing is great, a big improvement in comfort. Here is the chart of my first week with this equipment and SleepyHead (my thanks again to Pugsy, who told me where to download it, and to Nate, who told me how to switch the SD card to "locked" to download data).

Ok, here goes:

CPAP Statistics as of February 23, 2012

7 days of CPAP Data, between 2/17/12 and 2/23/12

AHI - 3.13, 2.45 (most recent and last 7 days)
Hours per Night - 07:02, 07:10 (most recent and last 7 days)
Pressure - 6.00, 6.00 (most recent and last 7 days)
Average Leaks - 4.18, 2.88 (most recent and last 7 days)
95% Leaks - 19.20, 18.00 (most recent and last 7 days)

How does this look?

One concern: Since beginning therapy, I have not so much Obstructive Apnea (as a component of these numbers)--the majority is Central Apnea, which strangely I had absolutely none of in my initial sleep study. This puzzles me and makes me uneasy. My doctor thinks that the therapy itself is causing the Central Apnea by artificially changing the carbon dioxide levels that my body is sensing--or something like that--and isn't worried. Does anyone else have this problem?

Also, I completely do not understand how leakage is being measured. The Respironics summary just said "Average Time in Large Leak Per Day = 5 minutes, 56 seconds" which was easy to understand. The above categories confuse me--is "Average Leaks" expressed in the number of minutes per night? Or per hour? Or is it a percentage? And what does the "95% Leaks" measurement mean? That number looks very high to me! I'm hoping that my leakage is not higher than it was with the old nasal pillows system.

Thank you for any insight you can give me,

Jane

Glad you like you new machine & software setup.

Looks like you've got some leaks to take care of.
How long is it since you have replaced your pillows on the Swift LT?
Do you know if you mouth breath at all during the night?
Have you tried APAP before?

Regarding the centrals, there is a small chance they might be pressure induced. If you were titrated at 6cm I think it would be fun for you to run your S9 in APAP mode with a pressure setting of something like 5cm to 7cm and see what the machine can do.

~UB

Hi Bob,

The pillows are brand new--I've only been using them a week. What has changed is that I'm using a Swift FX instead of a Swift LT (both are "for her"). With the Swift LT, I was in "leak" status only six minutes out of an entire night, which would seem pretty good.

Here's what I wrote about why I'm confused:

"Also, I completely do not understand how leakage is being measured. The Respironics summary just said "Average Time in Large Leak Per Day = 5 minutes, 56 seconds" which was easy to understand. The above categories confuse me--is "Average Leaks" expressed in the number of minutes per night? Or per hour? Or is it a percentage? And what does the "95% Leaks" measurement mean? That number looks very high to me! I'm hoping that my leakage is not higher than it was with the old nasal pillows system."

So, you see, first I'd like to figure out how my new leakage numbers with the new mask compare to my old ones, of six minutes during the whole night.

Sorry, I'm a real novice at this. What do you mean by changing my machine to between 5 and 7 cm (APAP?)? Does that affect leakage, or do you think this might give me fewer Central Apnea events? The doctor seems completely unconcerned, but I'm still uneasy!

Thanks for your reply--any education you can give me is appreciated; this is why I want to see my own numbers, so I can understand better.

Jane

Hello,

I just found this in the Help section of SleepyHead:

Average Time in Large Leak Per Day: Displays the average amount of time the patient spent with excessive air leakage that will compromise therapy. This could be the result of poor mask fitting.

So, the table they give me shows categories of leaks: one is the "Average Leak," which I might construe as meaning minutes per night that my mask is leaking, right? My seven-day average is 2.88--that is just under three minutes per night. Is that a bad number?

The other category is "95 Percent Leaks," which is NOT defined in SleepyHead's Help glossary, so I'm pretty much stumped at what that might mean.

ResMed machines generally display leak as the 95th centile value. These, technically, are the HIGHEST leak values which the machine encountered during the BEST 95% of the night, “best” meaning the portion of the night with the LOWEST leaks. Put another way, ResMed divides the time during which the machine is blowing into 60-second segments, computes the median leak during each 60-seconds, ranks them from lowest to highest, and reports the highest value encountered for 95% of the night.

The use of APAP is unrelated to leaks.
My suggestion was that if you have not tried APAP before that you try it now you have this wonderful machine for a week.
You may respond well to APAP. The S9 is capable of detecting centrals in APAP mode.

~UB

Hello!

Wow, are you a research scientist or mathematician? I will drink a cup of coffee and read the explanation again!!! I'm certainly impressed with your understanding, and only wish I could grasp it more quickly.

Do I have to have my doctor agree to change my setting? I really like the idea of getting my machine to help solve the central apnea problem. It scares the daylights out of me to have even one instance of my brain not telling my body to breathe.

Thanks so much for helping me with this. Now I'm going to get that coffee...

ResMed machines report excess leak meaning they subtract the masks vent/intentional leak rate before you see the leak number. ResMed says that leaks up to 24 L/min can be handled fairly well by the machine. Obviously you want to keep leak down as low as possible.
Short lived excursions to 24 L/min or above aren't the end of the world but you want to limit them as much as you can.

I pushed 20 L/min several times last night and my 95% leak shows it but I didn't hit 24 L/min and while not the prettiest of leak lines...I am okay with it. Some nights my leak line is like this and some nights it doesn't show much movement at all. It happens.
It won't take you long before you can just glance at the leak line and the numbers and quickly evaluate overall impact and move on.


Respironics machine report Total leak..meaning that report the excess leak and the intentional vent rate so they don't use the 24 L/min line in the sand. Instead Respironics gives us a "large leak number" which seems to be somewhere around 85 or 90 L/Min before they say the leak can impact therapy.
Repironics just says "Large Leak" and never really gives us a set number but my past experience with Respironics machines and large leaks...seems to get flagged around 90 L/Min.