Newbie: first night pressure + leak rate question

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
User avatar
Pugsy
Posts: 63942
Joined: Thu May 14, 2009 9:31 am
Location: Missouri, USA

Re: Newbie: first night pressure + leak rate question

Post by Pugsy » Sun Mar 11, 2018 8:02 am

RaveledSleave wrote:
Sun Mar 11, 2018 2:09 am
why are there two lines and why is one of them higher than the other? Should I be concerned about it? It doesn't feel like the mask is leaking.
Because you are using the Flex exhale relief option and creating 2 pressures being used. One for inhale (the top line) and one for exhale (the bottom line in the graph). So it's normal to see the 2 pressure lines when using the exhale relief option.

I think that you would do better with a little increase in that minimum pressure. When are you supposed to go back to see the doctor to have these settings evaluated?
The OAs and hyponeas (obstructive stuff) aren't horrible but could stand a reduction in numbers especially since there are so many snores, Flow limitations and RERAs flagged which aren't part of the AHI.
The AHI is just the CAs, OAs and hyponeas. The other stuff points to sub optimal pressure being used and the airway trying to collapse.

Your leak rate graph is actually quite decent. The times where you see the leak go up a little is because the pressure also increased.
The top leak line on the graph is total leak and total leaks is excess leak plus the mask's expected vent/intentional leak rate so the vent rate increases as the pressure increases.
You didn't even come close to large leak territory which is probably up around 80 L/min total leak numbers. Large leak territory red line moves as the pressure moves so as the pressure changes we expect the top line to change.
The bottom leak line is supposed to be excess leak only but it was never really perfected by SleepyHead's creator. The variations in the threshold for large leaks made it difficult for excess only leak calculations. It's close but not perfect.

For large leaks flagging concerns...look at the Events graph....see the LL at the near top of the Events graph? That's large leak and if you don't see any flags in the LL events graph you didn't have any large leaks.

That statistic for percent of "time over red line threshold" is actually not quite correct until you tell SleepyHead you are using a Respironics machine because the default install is for the ResMed machine red line threshold.
Go to Preferences/CPAP tab and change the 24 L/min default threshold to something more suitable for a Respironics machine.
Since the threshold varies as the pressure varies it's hard to come up with a perfect number to use but 70 L/min would be a good conservative number for you to use. The actual red line is probably higher but it won't hurt to use a more conservative number.

_________________
Machine: AirCurve™ 10 VAuto BiLevel Machine with HumidAir™ Heated Humidifier
Additional Comments: Mask Bleep Eclipse https://bleepsleep.com/the-eclipse/
I may have to RISE but I refuse to SHINE.

If you want to try the Eclipse mask and want a special promo code to get a little off the price...send me a private message.

User avatar
Jas_williams
Posts: 1120
Joined: Tue Dec 19, 2017 2:12 pm
Location: Somerset UK

Re: Newbie: first night pressure + leak rate question

Post by Jas_williams » Sun Mar 11, 2018 10:45 am

There are two lines on the leak rate (the top one is total leaks) the bottom line is unexpected leaks, as long as the second line is either not there or up to a value of about 24 the leaks are nothing to worry about. If the leaks become an issue the machine will raise a LL large leak flag


Jason

_________________
Mask: Bleep DreamPort CPAP Mask Solution
Additional Comments: Using sleepyhead and a pressure of 6 - 21 Resmed S9 Adapt SV with a Bleep Sleep Mask