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+--- Thread: Q: Autoset pressure range (/Thread-Q-Autoset-pressure-range)
Q: Autoset pressure range - FredH - 01-14-2021
My new Resmed Airsense 10 Autoset was preset from 10 to 20 for my diagnosed 11 pressure. (I had 11 on my S9 Elite for almost a decade.)
I want to understand. Please direct me to a good explanation of how minimum and maximum settings are determined for autoset machines.
Thank you.
RE: Q: Autoset pressure range - Sleeprider - 01-14-2021
Since the Autoset machine is capable of identifying obstructed and flow-limited breathing it is capable of increasing and decreasing pressure as, and when needed to prevent obstructive apnea and hypopnea. Using a minimum pressure slightly below your titrated therapy pressure offers the best chance of experiencing the most comfortable and effective pressure range, while minimizing disruptive pressure variation. You could cap the maximum, but the machine does a pretty good job of limiting pressure as long as there is not significant flow limitation present. You asked for a reference, and the best I know of is the clinical manual for the Airsense 10 Autoset that you can get from the forum at the link on the top of this page (CPAP Setup Manuals). The Resmed Clinical Titration Protocol is another good source https://www.resmed.com/us/dam/documents/products/titration/s9-vpap-tx/user-guide/1013904_Sleep_Lab_Titration_Guide_amer_eng.pdf
RE: Q: Autoset pressure range - Crimson Nape - 01-14-2021
It is a very sophisticated algorithm called, guessing. Your pressure settings are derived on your previous static setting and is based on the predicate that the pressure used was enough to address most of your apnea events. Again, based on the assumption that not all your apnea events need 11 cm of pressure to abate an event, a lower pressure is used. In fact, you may even be able to decrease this starting pressure further as you accumulate more data from the Autoset. Your upper pressure setting is this model's maximum pressure. Although it is set to 20 cm, it won't use this pressure unless it needs it. Resmed devices respond to flow limitations and airway obstructions with a higher pressure and will only increase the pressure high enough to overcome the sensed event. One of the few times that this scenario can cause a problem is when the patient has UARS. In that case flow limitations will persist regardless of the pressure the CPAP is using. UARS can and will cause the CPAP to increase its pressure to the highest set. With that said, that "inconvenience" can be addressed if and when it occurs. As you gain data, you may be able to reduce the upper pressure value. Reducing the upper limit will come into play when you have a bad night's sleep and will prevent the CPAP from turning into a personal leaf blower.
I hope I answered, at least part of, your question.
RE: Q: Autoset pressure range - Gideon - 01-14-2021
You did not post any charts. Post OSCAR charts and we can tell if you need/should change your settings. While I suspect your settings are at least close, and as such, acceptable, it never hurts to check. There is a misunderstanding out there that auto machines do not need to be adjusted. We have seen that the settings provided by sleep doctors are dialed in on occasion (rarely) most need to be optimized. Yours? don't know, haven't seen it. So post your nightly screenshot from OSCAR and we can evaluate it.
RE: Q: Autoset pressure range - sptrout - 01-14-2021
I have the same machine as you have and have to disagree somewhat with my AB friends. My original sleep study recommended a CPAP setting of "8" which I used as my target number for years, a little less than 8 for the minimum, setting the upper setting much higher, as much as 20 sometimes. Over the past year I have noticed that my only apnea events are now centrals and very, very rarely either obstructive or hypopenas. I also have noticed that my ResMed APAPs (I have 4 identical machines..long story) and they all want to climb up the pressure stairway for no obvious reason. IMO, this was causing the CAs and not fixing the non-existent O or H's. (BTW - - My AHI is fine always way less than 1.0)
The only way to test this theory of my was to reduce the upper limit setting down, then down, then down some more. The results was as I expected. I am now down to about 14 (lower setting around 7) and the CAs have been reduced with no change to the other apneas. Now, my AHI is usually less than .5 to near 0 most nights. The machines still want to climb that ladder, but never make it to 14, so I will probably reduce it more. If the AHI increases, I will just change the settings. Since I am self pay I can do anything I want, if you are limited by a doctor or insurance you make not have as much freedom.