ResMed S8 Elite w/software & reader

[arizonaartie]

I have a new S8 Elite with softward and card reader. I have 13cm pressure setting. I can't seem to eliminate all leaks with each of 3 masks tried. I usually have average 12.2 cm during night.
Question: Should I raise my setting to 13.8 and with leakage I'll attain the 13cm that I should have?

Also, what is AHI, AI and HI. My readout shows I have several of these events during the night. How many of these events is acceptable?

arizonaartie
ResMed S8 Elite w/humid.
Ultra Mirage FF Mask
F & P 431 FF Mask
Hybrid Mask
Aura Nasal Mask

[rested gal]

Acceptable is an AHI of less than 5.0. Doesn't really matter how the events are divided (apneas - AI, hypopneas - HI) as long as the total AHI is below 5.

Leak rate with a ResMed machine should be no more than .4

The Hybrid mask has a much higher airflow out the exhaust vent than most masks, so I don't know what the Hybrid's normally very high leak rate does to the ResMed leak data. Bear in mind that ResMed calculates leak in liters per second, while most other brands calculate leaks in liters per minute. You can check out the Hybrid's built in leak rate at dsm's handy chart:

http://www.internetage.com/cpapinfo/leak-rates-1.html

Something a leak rate can't tell you is where the leaks are coming from. A high leak rate could be from mouth air leaks or mouth breathing if a person is not wearing a full face mask. Or could be from mask leaks, a leaky hose, leaky connection...anywhere.

[Arizona-Willie]

[quote="arizonaartie"]I have a new S8 Elite with softward and card reader. I have 13cm pressure setting. I can't seem to eliminate all leaks with each of 3 masks tried. I usually have average 12.2 cm during night.
Question: Should I raise my setting to 13.8 and with leakage I'll attain the 13cm that I should have?

Also, what is AHI, AI and HI. My readout shows I have several of these events during the night. How many of these events is acceptable?

arizonaartie
ResMed S8 Elite w/humid.
Ultra Mirage FF Mask
F & P 431 FF Mask
Hybrid Mask
Aura Nasal Mask
======================
I have the S8 Elite setup also. I am supposed to have a pressure of 9cm although the doc said it was ok to go to 10.

My S8 gives me a reading for max pressure during the night much lower than the setting on the machine. In order for the machine to tell me the max pressure was 9cm, I have to set it at 9.8!!!

I asked Resmed and some girl in dire need of an education told me that the max pressure was and AVERAGE!!

By definition, max cannot be an average. There is a 90 percentile that it gives you which is a kind of average.

I don't know if the pressure guages on the machines are inaccurate or what.

I haven't bought a manometer in order to test it. But I pretty much keep my AHI under 5.

AHI is apnea / hypopnea index and AI is apnea index and HI is hypopnea index.

Two different way your air gets choked off.

We all shoot for zeros but it ain't gonna happen

If your AHI is under 5 .. good show.

[Bob...]

My S8 gives me a reading for max pressure during the night much lower than the setting on the machine. In order for the machine to tell me the max pressure was 9cm, I have to set it at 9.8!!!

Here is my spin on that. The S8 Elite and Vantage are the same machine hardware wise, with the difference being in the firmware. This is logical because the S7 series Elite and Auto Spirit were the same. In fact there is a upgrade that will make the S7 Elite an auto. I have never seen such an upgrade available for the S8, but I bet it could be done. The S8 Vantage displays the 95% pressure and the Elite, in my opinion, is trying to display the 95% pressure also, and is getting confused because the firmware was not changed to show the max pressure. I just ignore that reading as I know what I set the pressure at even if it doesn’t.

Bob

[hoyle]

Bob

I have the Resmed S7 Elite and have recently been changed to an auto cpap, so I purchased the Puritan Bennet 420E autopap.
You mentioned in your post that there is an upgrade for the Resmed S7 Elite to make it an Auto CPAP. Do you know if it is still available and from whom it can be ordered? If the upgrade is available, I can have a second machine as backup.

[Arizona-Willie]

My S8 gives me a reading for max pressure during the night much lower than the setting on the machine. In order for the machine to tell me the max pressure was 9cm, I have to set it at 9.8!!!

Here is my spin on that. The S8 Elite and Vantage are the same machine hardware wise, with the difference being in the firmware. This is logical because the S7 series Elite and Auto Spirit were the same. In fact there is a upgrade that will make the S7 Elite an auto. I have never seen such an upgrade available for the S8, but I bet it could be done. The S8 Vantage displays the 95% pressure and the Elite, in my opinion, is trying to display the 95% pressure also, and is getting confused because the firmware was not changed to show the max pressure. I just ignore that reading as I know what I set the pressure at even if it doesn’t.

Bob

===============
My autoscan software reports the 95th percentile and a median and the max pressure for the period.

Currently it is set for 9.8cm of pressure and the software reports

95th percentile 9.0
median 8.8
max pressure 9.2


all three figures it reports are different and none match the pressure setting of the machine.

Last week I had it set for 9.6cm and the max hit 9.0 right on the nose.

I am experimenting by slowing increasing pressure until I find the " sweet spot " where the AHI is the lowest. When it starts going up I will back the pressure down.

I suppose the only way to be absolutely sure which is right is to buy a manometer so I can check the pressure myself and see what is actually coming out of the hose.

It's a darn good thing pressure isn't extremely critical. Being off a little one way or the other won't kill me.

But, considering what they charge for these machines, you would think they would at least have accurate sensors.

My software / sensors are at least consistent. From the day I started taking screenshots with the software and posting them into Microsoft One Note ( end of July ) the max pressure reported has always been .6 cm below the pressure setting on the machine.

Perhaps there is a reason for this. If the girl at Resmed tech funnies was right and it is an average, then they shouldn't call it max.

I suppose it could be an average. 95th percentile and median are not the average. Technically speaking. Understanding the differences always gave me a headache

But if it is, they shouldn't call it max. Hmm what would an average of the maximum pressures be called?

This gets confusing ... grrr

[Bob...]

Do you know if it is still available and from whom it can be ordered? If

the upgrade is available, I can have a second machine as backup.

This was the only site that I knew of that advertised it, but looks as if no longer available:

Item #30932

http://www.cpapwholesale.com/resmed-s7-elite-cpap.htm

This gets confusing ... grrr

Ain't that the truth!!!

I don't believe it is the sensors that are at fault, my money is on software and/or firmware.

Bob

[Bookbear]

When I saw my sleep doc for the first time (a month after I had the machine, had been seeing the doc's PA before), they told me to bring the machine (ResMed Vantage S-8) in with me, and the first thing the nurse did was check the pressure. It was set at 10, and according to their gage was actually providing 10.1. I was told not to worry, that some variance was normal. I thought these were precision machines? The phrase 'close enough for government work' springs to mind...

[Bob...]

It was set at 10, and according to their gage was actually providing 10.1. I was told not to worry, that some variance was normal. I thought these were precision machines? The phrase 'close enough for government work' springs to mind...

I haven't been able to find anything on the ResMeds, but the "REMstar Auto with C-Flex & REMstar Pro 2" Service Manual states that the static pressure accuracy is "+/- 1.0 cm H20".

Yours was off by only "0.1".

Bob

[billbolton]

It was set at 10, and according to their gage was actually providing 10.1. I was told not to worry, that some variance was normal. I thought these were precision machines?

That's a 1% variation.

Normal engineering tolerances are 10%.

Cheers,

Bill

[Knightfall]

Does anybody know if using EPR affects this reported pressure? For example, my intial therapy pressure was 9 cm/h2o; EPR was set at 3, or a drop to 6cm/h2o. My daily average during this time period was 7.8 cm/h2o. My leakage varied during this time period from 0.02 to 0.12 L/s; daily pressure was consistently 7.8. Just curious what other Resmed machine users are seeing, and if having EPR disabled brings this reported pressure closer to therapy pressure. Ken

[Bob...]

Does anybody know if using EPR affects this reported pressure?

Mine doesn't seem to, at least in the same way yours may. With EPR at 3 my pressure (6) runs from 6 to 6.6.

Bob