CPAP or APAP on a battery

AZdreamer wrote: ↑

Thu Sep 08, 2022 9:19 pm

I’ll toss in a data point which may or may not be useful. I used my Z2 this past weekend for one night using the HDM/Breas battery (which is rated 99Wh). My settings were APAP, min 12cm, Z-breath 3. I slept for 8+hrs with a 95% pressure of 13. Two bars remained on the battery in the morning meaning, according to the manual, that 35-63% of the charge remained. That suggests to me that a 65Whr battery might just cover one night….

Thanks.

Even though I don't have time to experiment with the battery I decided that I could experiment with the machine since I've never used APAP. I downloaded the NiteLog software set it up and then changed the settings on my Breas Z2 to APAP with a minimum of 8 and a maximum of 14 cm. My normal settings are CPAP at 14 cm. I learned that 8 is probably too low for the minimum in my case becaused it raised my AHI to above 5 for most of the night. However 8 to 14 cm did result in being in the mild sleep apnea range for all but one hour. The other result was that the machine stayed in the 8 cm or slightly higher range all night except for one spike of 22cm.

That 22 cm spike doesn't make any sense to me. 1) The machine can't go above 20 cm and 2) I set the maximum pressure to 14 cm. What's up with that? I don't get it. Can/will anyone explain that?

While I really like the Z2 machine I've got to say I'm unimpressed with the nitelog software. It seems amatuerish and crude to the point of being almost useless. Ditto for the user manual. I downloaded OSCAR before I realized that it didnt support the Z2 and that's a nice and useful program.

litetrek wrote: ↑

Sat Sep 10, 2022 8:20 am

That 22 cm spike doesn't make any sense to me. 1) The machine can't go above 20 cm and 2) I set the maximum pressure to 14 cm. What's up with that? I don't get it. Can/will anyone explain that?

I'm surprised you ask. It's just a random error in the data.

litetrek wrote: ↑

Sat Sep 10, 2022 8:20 am

That 22 cm spike doesn't make any sense to me. 1) The machine can't go above 20 cm and 2) I set the maximum pressure to 14 cm. What's up with that? I don't get it. Can/will anyone explain that?

I don't know how the Z2 reports pressure or what exact terminology the reports use, but there are two pressures, intended pressure and actual. Many machines/OSCAR report them as, Pressure and Mask Pressure.

Using the language used in OSCAR:

• Pressure is the pressure the device is current set to push.
• Mask Pressure is the actual pressure being measured.

And Mask Pressure can go above the intended pressure, because the machine is not the only thing influencing pressure. We are also influencing pressure.

Exhale vigorously or sneeze and you will see a pressure spike well above the the machine's pressure.

litetrek wrote: ↑

Thu Sep 08, 2022 11:10 am

Dog Slobber wrote: ↑

Thu Sep 08, 2022 8:57 am

Asking what mode CPAP or APAP uses more energy, doesn't really make sense.

What ever mode spins the blower more will use more power. And that is dependent on what the specific APAP settings are and where the device is all night.

Given the Z2 isn't supported by OSCAR there is no way to tell.

On systems supported by OSCAR, one could take a look at their Med EPAP and IPAP, then average them for CPAP mode and APAP mode. The lower value will consume less energy.

I agree withn everything you've said. But there are people on this board who use the Z2 prescribed to be set at 14 cm who have compiled data in APAP mode. I know that because it was stated in some threads. Having that data compared to no data at all even if it doesn't apply to my medical situation is better than nothing. I'm hoping someone with a similar set-up will provide some information. Its better to interpolate than extrapolate but sometimes extrapolation is all you've got.

Seeing such a post on CPAPTalk is very unfamiliar, especially given the low market share of the z2, the specific nature of the data and pressure. I would not give the compiled data, as you remember it, much credibility.

Yes Nitelog is terrible. However you can glean some basic info from it, enough to accomplish your goal. If the pressure is staying down near 8cm then you will certainly get more run time from your power banks. How did you feel with an ahi over 5? As you realized, you probably don't want to set the minimum pressure to low and stress your body to much. I'm sure the doctor would advise against it, but that's your choice. Oxygen can get low, your heart can be stressed, etc. Pay attention to what your body is telling you. If your getting bad wake ups then you probably want more pressure. I'm sure your familiar with all the symptoms before you got a pap machine or when you went without it.

Rob K wrote: ↑

Sat Sep 10, 2022 9:31 am

Yes Nitelog is terrible. However you can glean some basic info from it, enough to accomplish your goal. If the pressure is staying down near 8cm then you will certainly get more run time from your power banks. How did you feel with an ahi over 5? As you realized, you probably don't want to set the minimum pressure to low and stress your body to much. I'm sure the doctor would advise against it, but that's your choice. Oxygen can get low, your heart can be stressed, etc. Pay attention to what your body is telling you. If your getting bad wake ups then you probably want more pressure. I'm sure your familiar with all the symptoms before you got a pap machine or when you went without it.

My normal AHI is 1 at 14 cm in CPAP mode. 8 cm is too low for me in my opinion and now I know. However, at 8 cm I go from AHI of one to around 10. My goal is to get it under 5 at whatever setting. Regarding how I slept, that is not a good measure for me. I have back pain and have never slept well even before I had sleep apnea. Also, I have been chronically tired since I was a teenager. The cpap improved but didn't fix that.

I also monitored my o2 level all night but I haven't looked at those results

ChicagoGranny wrote: ↑

Sat Sep 10, 2022 8:30 am

litetrek wrote: ↑

Sat Sep 10, 2022 8:20 am

That 22 cm spike doesn't make any sense to me. 1) The machine can't go above 20 cm and 2) I set the maximum pressure to 14 cm. What's up with that? I don't get it. Can/will anyone explain that?

I'm surprised you ask. It's just a random error in the data.

I agree its an error - thats why I asked about it. Knowing the source would be helpful. I think another poster has answered that.

Dog Slobber wrote: ↑

Sat Sep 10, 2022 8:35 am

litetrek wrote: ↑

Sat Sep 10, 2022 8:20 am

That 22 cm spike doesn't make any sense to me. 1) The machine can't go above 20 cm and 2) I set the maximum pressure to 14 cm. What's up with that? I don't get it. Can/will anyone explain that?

I don't know how the Z2 reports pressure or what exact terminology the reports use, but there are two pressures, intended pressure and actual. Many machines/OSCAR report them as, Pressure and Mask Pressure.

Using the language used in OSCAR:

• Pressure is the pressure the device is current set to push.
• Mask Pressure is the actual pressure being measured.

And Mask Pressure can go above the intended pressure, because the machine is not the only thing influencing pressure. We are also influencing pressure.

Exhale vigorously or sneeze and you will see a pressure spike well above the the machine's pressure.

Thanks. I appreciate the response. What you explained is probably what happened. I sneeze into my mask several times each night and its a full face mask sp that would explain a spike.

Thanks for all the comments folks.