I need Help Understanding how a ResMed VPAP Auto 25 Works

[fredn]

Hi ... my wife has been using a ResMed VPAP Auto 25 since the beginning of November, 2010. When I say using I guess I should really be saying "Using as long as she can stand it" .....

She just about always has problems getiing much past 4-5 hours a night .... on a real good night she might make 6 hours ... the problem is that her left nostril gets sore ... a burning feeling when she uses if for more than say 4 hours.

I'm trying to figure out what may be wrong ....

I'm thinking that ideally if the machine could adjust the pressure, providing a bare minimum when there are no obstructions, but increase pressure when it's needed to get past obstructions, that that would be good. Less pressure on her nose until it's needed. I don't know ... is that the way that her VPAP Auto 25 should work? Maybe it's setup wrong?

So I went into Clinical Mode to see what the settings are:

Here's what I found .....

Basic Settings:
Mode: VAUTO
Max IPAD: 16.0
Min IPAD: 11.0
Pressure Sup: 4.0
Ti Max: 2.0s
Ti Min: 0.3s
Exhalation: Slow
SmartStart: Off
Mask: Swift

Advanced Settings:
Leak Alert: Off
Trigger: Med
Cycle: Med
Tube Length: 2M
Max Settle: 45 minutes.

I have a reader and software so I went back over what it has been recording ....

On the days where I have "Detailed Information: The pressure is ALWAYS FLATLINE at 15 ..... is this right? She doesn't have very many hypopnea's and rarely an apnea .... should the machine be dropping to a lower pressure when it's not needed .... hopefully giving her some relief ...

Any help would be greatly appreciated ..... I'm ok with anything you lay on me .... if I don't understand right away I'll ask,

I really need to see if I can get this Machine more comfortable for her .... we need to get it to the point that she can wear it anytime that she is sleeping.

She had AFIB and just got it reverted and she's feeling a 1000% better .... I hate to have her sleep apnea trigger it back cause she can't shtand wearing the machine.

Fred

[robysue]

Hi ... my wife has been using a ResMed VPAP Auto 25 since the beginning of November, 2010. When I say using I guess I should really be saying "Using as long as she can stand it" .....

She just about always has problems getiing much past 4-5 hours a night .... on a real good night she might make 6 hours ... the problem is that her left nostril gets sore ... a burning feeling when she uses if for more than say 4 hours.

This sounds more like a NASAL PILLOWS problem to me than a PRESSURE problem. Does she sleep on her side most of the night? If so, it could be that she's sleeping in such a way that the nasal pillows are ever so slightly misaligned because the mask is being shoved slightly by her bed pillow. And by the end of four hours, the tippy-tip of the nasal pillow cone that goes into the nostril has irritated the nostril enough to wake her up.

If she's sleeping on her left side, then so-called rainout might also be aggravating the issue. Sometimes the tiny bit of water from rainout that gets into my nostrils leads to a slightly burning feeling. Not at all comfortable.

Have her try using Lanisoh or KY Jelly on the spot that she knows is going to get sore by the end of four hours. That may make a difference. Also make sure she's NOT inserting too much of the nasal pillows into her nostrils. And keep the straps comfortably loose.

[fredn]

Hi robysue ....

She sleeps on both sides as well as her back. And she does use Lanisoh or some other lanolin based product designed for breast feeding women. Part of the problem may well have to do with the pillows. She is claustrophobic and we have been having a hard time getting a mask that she ok with also.

BUT what I am trying to understand here is if the Machine is SET and WORKING properly. It would seem that if there are no obstructions the pressure ought to drop down much lower and MAYBE, just matbe, less pressure will be more comfortable for the long haul.

Thanks ..... Fred

[robysue]

I'm thinking that ideally if the machine could adjust the pressure, providing a bare minimum when there are no obstructions, but increase pressure when it's needed to get past obstructions, that that would be good. Less pressure on her nose until it's needed. I don't know ... is that the way that her VPAP Auto 25 should work? Maybe it's setup wrong?

It's important to realize that the increase in pressure does NOT let your wife "get past obstructions". Rather, the increase in pressure prevents future obstructions from happening. When the machine starts to increase pressure in response to an ongoing event, that event won't magically end. But by increasing the pressure, the machine is making it less likely that more events will follow in quick succession to that first one. The machine continues to increase pressure as long as "events" are happening----in other words as long as the machine is detecting disordered breathing of some sort, it will appropriately increase either the IPAP, the EPAP or both. Once nice regular, ordered breathing is being detected for a sufficient amount of time (several minutes I believe) the machine slowly decreases pressure until one of two conditions are met: The min settings are reached OR disordered breathing is again detected.

So I went into Clinical Mode to see what the settings are:

Here's what I found .....

Basic Settings:
Mode: VAUTO
Max IPAD: 16.0
Min IPAD: 11.0
Pressure Sup: 4.0
Ti Max: 2.0s
Ti Min: 0.3s
Exhalation: Slow
SmartStart: Off
Mask: Swift

I use a PR S1 BiPAP instead of the Resmed VPAP, but I'm somewhat familiar with the meaning of these settings. Mode=VAUTO means the machine should be in AUTO mode where it automatically adjusts the pressure. Looks like IPAP is allowed to range from a low of 11cm to a high of 16cm. Pressure Support = 4 means that IPAP - EPAP will never be larger than 4. (So I'm guessing that her EPAP range is between 9cm and 12 cm.) Ti Min and Max have to do with how fast the change from EPAP to IPAP occurs when your wife starts to inhale. And Exhalation = Slow probably has something to do with how fast the drop to EPAP is done, but I really don't know about that one. SmartStart=Off means the machine won't turn itself on when it detects breathing through the mask and the mask type is set to Swift---which indicates (I think) that your wife is using a nasal pillows mask---most likely a Swift FX or a Swift LT.

Advanced Settings:
Leak Alert: Off
Trigger: Med
Cycle: Med
Tube Length: 2M
Max Settle: 45 minutes.

If the machine detects a large leak, the Alert buzzer won't go off. Trigger has something to do with how the machine detects the end of the exhale and the beginning of the inhale of each breath. It's set to medium, which I believe is the default. Cycle probably has something to do with cycling from EPAP to IPAP and back to EPAP, but the PR BiPAP doesn't have this sophisticated of a level of control over how the EPAP/IPAP/EPAP transitions are made. Max Settle = 45 minutes may be the maximum ramp time allowed to be set by the user through the user menu.

On the days where I have "Detailed Information: The pressure is ALWAYS FLATLINE at 15 ..... is this right? She doesn't have very many hypopnea's and rarely an apnea .... should the machine be dropping to a lower pressure when it's not needed .... hopefully giving her some relief ...

This does sound fishy to me. Almost like the machine is running in straight CPAP set at 15cm. But---with out actually seeing the graph and its LABELS I'm just speculating. In order to get detailed data information for every day, I think you need to download the data at least once a week and be sure to select "download all data" when ask which data to download.

Could you post an image of the graph?

Also as a quick test of whether the machine is at least cycling through EPAP/IPAP/EPAP correctly, you can have your wife do this: Put the mask on and turn the machine on. The LCD then should start showing a readout of the current pressure being delivered. If it is switching back and forth as your wife is breathing in and out and one number is labeled with an I and the other with an E. You could even have your wife try to "fool" the machine into increasing the pressure by having her hold her breath for as long as she can (10 seconds or more) since the machine may interpret this as an event. Or she could try to make snoring noises with the mask on for a minute or two. And what what the pressure numbers when the machine is delivering pressure actually do.

Best of luck

[fredn]

FYI .... I try to download everyday .... those are the only days that I will get detailed for.

Here's the chart



Fred

[robysue]

Hi robysue ....

She sleeps on both sides as well as her back. And she does use Lanisoh or some other lanolin based product designed for breast feeding women. Part of the problem may well have to do with the pillows. She is claustrophobic and we have been having a hard time getting a mask that she ok with also.

I understand the claustrophobia. Nasal pillows are the only mask type that I can tolerate too. If your wife's pillow is a very firm pillow and also somewhat thickish, that's probably slightly jarring the mask when she turns over and that in turn probably slightly misaligns the nasal pillow in her left nostril.

So while I think that the nasal pillows may be triggering your wife's problem of waking up with the sore nostril, I also think this is a problem best addressed by looking at what can be done concerning the BED pillows and BED covers and how the hose is running from the machine to her face instead of just swapping for a less desirable mask.

I too sleep mainly on my sides and use the Swift FX. I find that I need a very soft, very squishy pillow that I can mold to both my head and the hose works best for me. I use a very worn out 25+ year old down pillow that's literally held together by being inside two feather proof zipper pillowcases and then the main pillowcase. Others here swear by the buckwheat pillows that are commonly available. If your wife likes a very firm or thick pillow, she may need a special CPAP pillow with cutouts where the hose can dangle without jarring the mask too much. For me, the soft, squishy pillow is all I really need to keep my nose from getting too sore on most nights. (Chapped lips, however, are a different ball of wax altogether for me.) So I just run the hose directly under the cover and hug it like a large stuffed toy snake. (It's in a hose cozy so it doesn't feel plasticky.) But if your wife is also finding dealing with the hose is an issue, then a hose management system may also help by taking off some of the pressure on the small, heavy hose directly attached to the Swift FX mask that I think your wife is using.

BUT what I am trying to understand here is if the Machine is SET and WORKING properly. It would seem that if there are no obstructions the pressure ought to drop down much lower and MAYBE, just matbe, less pressure will be more comfortable for the long haul.

See my second post. Also---if you cannot determine whether the machine is adjusting the pressure at all, you should take it back to the DME and have it checked out. That graph you describe sure sounds like it's running in straight CPAP mode.
[/quote]

[robysue]

FYI .... I try to download everyday .... those are the only days that I will get detailed for.

Here's the chart



Fred

That graph really does look like the machine is running in CPAP at 14cm or 15cm. Either that OR the STARTING IPAP is somehow set to 14cm and on this particular night, the pressure never increased because there were no events serious enough or close enough together to trigger a pressure increase.

In VAUTO mode, I would expect the pressure graph to have at least TWO lines: One for the EPAP pressure and one for the IPAP pressure. I'd also actually expect a line drawn at the Max IPAP and the Min EPAP.

By the way in that clinical menu, are you sure the pressure settings read:

MAX IPAP: 14.0
MIN IPAP: 11.0

instead of that second one being MIN EPAP: 11.0?

I ask because if her in EPAP is 11cm and the default IPAP-EPAP = 3 on the Resmed (I don't know this for sure), then that would make her starting IPAP = 14 and that so that line could be just the IPAP line being drawn flat at it's minimum value for the whole night because nothing happened.

To be on the safe side, however, I'd take the machine back to the DME with the ResScan report and ask them why there's only one pressure line and whether they could check to make sure the machine is working properly or if it is somehow "stuck" in CPAP mode.

[jnk]

If there are comfort issues with the pressure, ask the doc if you can lower the minimum EPAP a few cmH2O, maybe to 9 or so.

Although you are running in VAUTO mode, which is autobilevel mode, there isn't much room for pressure variation at those settings. With 4 cm of PS and only 5 cm difference between minimum EPAP and maximum IPAP, there is only 1 cm of play for the auto to work with, because of the way that machine works, which is very different from the other brand. If the minimum EPAP is lowered and the Settling feature is used, she may be much more comfortable. Then it will behave in the way you expect an autobilevel to behave.

Getting the humidification just right should help, too. A hosecover may allow for more humidity with less rainout if she is getting too dried out.

[fredn]

By the way in that clinical menu, are you sure the pressure settings read:

MAX IPAP: 14.0
MIN IPAP: 11.0

instead of that second one being MIN EPAP: 11.0?

OK .... I double checked the settings .... the second on IS MIN EPAP: 11.0 like you suggested. If I "mouse over" the line it is flat-lined at 15.0 ....

I also checked another graph .... one that had an twp apneas ..... the line is still flat during both of these apneas ... still at 15.0

[fredn]

If there are comfort issues with the pressure, ask the doc if you can lower the minimum EPAP a few cmH2O, maybe to 9 or so.

Although you are running in VAUTO mode, which is autobilevel mode, there isn't much room for pressure variation at those settings. With 4 cm of PS and only 5 cm difference between minimum EPAP and maximum IPAP, there is only 1 cm of play for the auto to work with, because of the way that machine works, which is very different from the other brand. If the minimum EPAP is lowered and the Settling feature is used, she may be much more comfortable. Then it will behave in the way you expect an autobilevel to behave.

Getting the humidification just right should help, too. A hosecover may allow for more humidity with less rainout if she is getting too dried out.

Hey jnk .... should I give it a try? Should I lower the Min EPAP? And what is this settling feature you talk about? Right now it is set for Settling 45 minutes ... my understanding is that it will start off at a lower setting and work its way up ... is that what you mean?

My thoughts are that lowering the MIN EPAP really can't hurt anything as long as I don't move the MAX and it's able to increase if needed

Fred

[fredn]

How exactly is the Machine supposed to work if it's in VAUTO Mode, with the MAX IPAP: 16.0, the MIN EPAP: 11.0, and the Pressure Support: 4.0.

Interesting that the MIN EPAP is 11.0 and the Pressure Support is 4.0 and it's seemingly stuck at 15.0 (11.0 + 4.0 = 15.0)

I'm gonna see if I can find an explanation for "pressure support"

Fred

[jnk]

Hey jnk .... should I give it a try? . . . My thoughts are that lowering the MIN EPAP really can't hurt anything as long as I don't move the MAX and it's able to increase if needed

Fred

Personally, I'm not comfortable suggesting what someone else should do, since I don't know why the doc prescribed that the machine be set up the way that it is. Docs know about other conditions and family histories and the like.

If it was me, and I was having no apneas to speak of and few hypopneas, and I was uncomfortable from the pressure, then I would seriously think about lowering my EPAP Min. But that's just me with my medical situation. My primary doc has given me permission to mess with settings on my machine.

It is my opinion that many times an RT will get a doc's Rx for specific pressures for bilevel and will set up an autobilevel to run as a straight bilevel. The whole idea of settling is to stay at the lowest pressures for an amount of time, and if the lowest setting is 11, that is the lowest it will go, which sort of defeats the purpose of settling.

Are you on speaking terms with the RT at the DME who set up the machine? It might be considered a courtesy to run the idea by him/her, at least. Sometimes the RT will make a quick call to the sleep doc and then everyone is happy.

If that doesn't work out, changing settings on one's own may be better than not using the machine because of of discomfort. But that is the sort of call one has to make on one's own, in my chicken-livered opinion.

[jnk]

How exactly is the Machine supposed to work if it's in VAUTO Mode, with the MAX IPAP: 16.0, the MIN EPAP: 11.0, and the Pressure Support: 4.0.

Interesting that the MIN EPAP is 11.0 and the Pressure Support is 4.0 and it's seemingly stuck at 15.0 (11.0 + 4.0 = 15.0)

I'm gonna see if I can find an explanation for "pressure support"

Fred

If the pressure it is reporting to you is the IPAP, and if there are no indications of obstruction occurring to raise the pressures, then IPAP would naturally stay at 15 all night, since the PS is 4 and the minimum EPAP is 11, and 11+4=15.

Feel free to ask more questions about my math on that.

[fredn]

I'm not super thrilled with the level of communications that has been going on since we've had the CPAP Machine .... it seems like they expect us to know what to do and come to them when we need something and tell them what the solution is ..... rather than them really knowing all of the options to try and make this thing more comfortable for her.

I do Computer Problem Determination for a living ..... these guys fail at PD

As long as they have thier $$$$ ....... ooops .... did I say that.

Fred

[fredn]

I went back over maybe 60 or so detailed reports ...... everyone is flat-lined at 15.0 ..... except for 3 instances where it did go up to 16.0. There were no apneas or hypopneas when it went up to 16.0 though .... so I don't know what's going on.