A few newbie questions

[ca_hosehead]

I'm just getting started with CPAP, I was diagnosed with severe (AHI a little over 50) OSA. I got the RemStar M Series Auto machine and it's giving me back a lot of stats that I don't really understand. Perhaps you can help?

After 4 nights here's what it's showing.

Usage per night: 3:30 - I wear the thing about 7 hours per night continuously. Why the low number?

90% pressure: 11.8 - This looks about right. The sleep study came back with a prescription of 11.

Leak - 40.8 L/min. I this good? Bad? Do I care? There seems to be a leak in the mask, not around edges where it contacts the skin, but in the hose where it connects to the elbow joint, where the quick release is.

AHI 2.6 - Looks like a good number. Can you get it lower? Should you try?

I assume that the software will give me more insight into all of this? I'm bit of a tweaker so I assume I'll wind up getting into reading the smart card. What do I get?

I'm sleeping one HELL of a lot better.

[Snoredog]

your usage number will go up the longer you use the machine or greater than 7 days. The machine reports a 7-day and 30-day average, so what you are looking at are partial weekly averages or partial 30-day averages depending on where you got the data. If you stop/start the machine several times per night for bathroom breaks that can also cornfuse the machine, but if a report is pulled off the machine it will show actual useage per night.

there may be some "bench" time on the machine if it is new for factory testing so the first week's use would include that session data in the results.

Leak Rate: Your mask came with a flow chart sheet, you look up your 90% pressure and find the flow rate at that corresponds with that pressure. Then you can compare the LCD leak data to the intended leak rate. If the LCD is higher than the mask is leaking where the cushion meets the face (or hole in hose etc.).

With continued use your 30-day stats will update, those are a better indicator of how you are doing on the machine than the 7-day average. Your numbers look good, I wouldn't do anything but use it.

[Knightfall]

Leak - 40.8 L/min. I this good? Bad? Do I care? There seems to be a leak in the mask, not around edges where it contacts the skin, but in the hose where it connects to the elbow joint, where the quick release is.

Welcome,

I would say this leakage is very good. Assuming a 90% pressure of 11.8 cm, the vent flow rate for your mask is roughly 38 L/min. Your actual leakage number would be the difference between these two, or 2.8 L/min (.047 L/s). I use a different manufacturer machine (Resmed) that would categorize that leakage as "excellent".

As far as where the "leakage" is coming from, your mask is designed to port off its exhaust through the vent. This is located on the 90 degree quick disconnect under the vent cover.

Sound like a good start; best of luck! Ken

[ColoradoDreamer]

Welcome and congrats on what appears to be that you are adjusting well.

I agree with the other posts that your numbers look good.

I would not be concerned with the low machine hours. It is only a 7/30 day average that you are looking at. I calculate that you used the machine roughly an average of a little over 6 hours for each of the 4 nights. I am waiting for my card reader for the software but until then have been tracking myself with the 7 and 30 day averages. By day eight your numbers should be looking better and in two weeks it should be as good as it is going to get for the 7 day average. Wait 30 days for the 30 day ave to look realistic.

Masks are designed to leak from holes somewhere on the mask or the elbow joint to expel the CO2 we generate.

Hope you continue to have nothing but success with your treatment.