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Sierra

Sierra
Joined Jul 2018
Bio

CPAP: AirSense 10 AutoSet

Set to CPAP Fixed Mode

Pressure 11 cm

Ramp: Auto

Ramp Start: 9 cm

EPR: 2, Full Time

Mask: ResMed AirFit P10 Nasal Pillow

Canada

Sierra
Joined Jul 2018
Bio

CPAP: AirSense 10 AutoSet

Set to CPAP Fixed Mode

Pressure 11 cm

Ramp: Auto

Ramp Start: 9 cm

EPR: 2, Full Time

Mask: ResMed AirFit P10 Nasal Pillow

Canada

To be clear while I am a retired professional with a technical background, but I am not a physician or a sleep technician. These initial settings are for comfort only and each user tends to set up their preferences a little differently, but here is basically what works for me, to be as comfortable as possible to go to sleep each night. They are listed in the order they appear in the setup menu.

Minimum Pressure: 7 cm

Ramp Time: Auto

Start Pressure: 7 cm

EPR: On

EPR Type: Ramp Only

EPR Level: 3

What this will do is start you out with an Inhale pressure of 7 cm, and with the EPR (Expiratory Pressure Relief) setting of 3 cm, it will reduce the pressure to 4 cm which is the minimum for the machine on each exhale. 7 cm to most people feels very comfortable. It should feel like you are getting air in very freely without any restriction from the mask. Exhaling against 4 cm is easier, and the machine can't go any lower. This will continue at these pressures until the machine decides you are asleep. Then it ramps up to the minimum pressure of 7 (and it is there already). But the EPR will stop, and you will be exhaling against 7 cm, which should be comfortable as you are asleep. The purpose of using the auto ramp is to enable the EPR to only be used during the ramp period. Since apnea is as likely to occur on exhale as on inhale, the higher exhale pressure will be more effective in treating the apnea. The machine will not have to ramp up as soon to stop apnea occurring. In my case shutting the EPR off during sleep reduces the maximum mask pressure by about 2 cm. But that is kind of an individual thing.

This said I would consult with your sleep clinic and get some advice on pressures they used during your CPAP trial which looked pretty good. You should tell them about the high central apnea too, and get their opinion on that. They may want you to come back in for a titration study to find out at what pressure you may be more susceptible to central apnea. With SleepyHead you will also be able to observe that for yourself. It flags when events occur, and you will see what the pressure is. The other thing that SleepyHead will flag is the time one is in Cheyne Stokes Respiration (if at all), which is a specific type of central apnea. CSR can run up the central apnea count quite quickly.

For now it shouldn't hurt to leave your max pressure at 20. Down the road when you see what is going on with SleepyHead and get some advice from your clinic you may want to reduce that. If pressure is inducing your central apnea it may be necessary to limit the pressure and allow a little more obstructive apnea, but get less central apnea. That 8.3 cm pressure you saw reported is the 95% number, so 95% of the time your pressure was under 8.3 cm -- which is quite low. When you get more data and advice from your clinic, it may be possible to lower your maximum pressure to 9 cm or perhaps even less.

In my case I have made pressure changes over 20 times trying to find an optimum. What I found is that I was setting the minimum and maximum closer and closer together. In my current mode I have the maximum set at 12.2 cm and the minimum at 12.0 cm, or in other words essentially in fixed CPAP mode. Only 4 days into that mode, but so far my AHI is down noticeably. It seems possible that a fixed pressure during the night may do just as well or better than the machine's fancy algorithm constantly changing pressure all night!

Hope that helps some. Any questions just ask. Pages 2-11 in that technical manual is a good read. I believe Cheyne Stokes is explained as well.

I take it you are getting these values from the sleep report on the AirSense machine? If so have a look at page 19 of this AirSense technical manual for an explanation of what they are. The leak rate you have is very low, and I would suggest you are not losing air out of your mouth based on that low number. It is the 95% leak rate which means during the night your leak rate was below that rate for 95% of the time. To get a happy face for leak rate you only need to have a leak rate less than 24 L/min for 70% of the night. It is a very lax target, and the number value is more accurate. I try to be under about 16 L/min.

Yes, you should ask for a written copy of the sleep report for your records. It should give a lot more information and include your oxygen values as well.

You should ask the clinic for details on how the test machine was set up, compared to where you are with your own machine. There seems to be a very big discrepancy in the effectiveness.

If you have a PC or a Mac with a SD card reader I would suggest you download SleepyHead. It is free software that lets you look at how your machine performed. It gives the time of each apnea event on a graph along with many other variables. I find it essential in monitoring my machine performance. Here is a link to a basic instruction manual. If you need any help just ask.

Who is setting up your machine for you? Yourself, or a sleep technician? Your current settings of 4-20 cm are the default out of the box values, and probably could be optimized at least for more comfort, and possibly better performance. The red flag however in what you have reported is the frequency of central apnea events. A CPAP using pressure does not address central apnea very well, and in fact the AirSense is programmed to ignore it and not increase pressure. In some individuals starting CPAP treatment can increase the frequency of central apnea. I am one of those individuals. However, my increase was not as high as the 15 range you report.

Yes, you can get a much more detailed report out of SleepyHead. You need a PC or Mac, and a SD card reader. After you install the software you can take the SD card out of the ResMed and transfer the data to SleepyHead. It should help you identify opportunities to see if the pressure can be adjusted. I will post a screen shot below as an example of what you will see. You can download SleepyHead at this link. It is freeware. And here is a link to a basic manual. Depending on your model of SPO2 monitor you may be able to display that data too. Click on the Oximeter link on the main SleepyHead page for more info.

Are you using the EPR feature? If so you may be able to gain a maximum mask pressure reduction by simply turning it off. Both myself and my wife use EPR at 3 but only during the ramp period.

Here is a screen shot from my wife's ResMed S9. She runs a pressure a little higher than mine, and close to what you have. She objects to the higher pressure so it is limited by the maximum pressure setting. Her values are min 12.8 and max of 14.4. This is not quite enough to totally control the flow limitations, but she dislikes having it higher, and over the longer term averages an AHI of about 1. She is currently using a F&P Brevida nasal pillow mask. It generally works well, but she does get some significant leaks during the night for short periods of time. I suspect from what I can hear that she dislodges it out of place to cause the leak.