For all of you who don't know the difference between A-Flex and C-Flex on Respironics CPAP machines, you're in good company. Each is a comfort option on the most popular Respironics CPAP machines that makes it easier to tolerate CPAP treatment. A-Flex is a little more comfortable than C-Flex, in that it provides pressure relief on both inhalation and exhalation. C-Flex only provides pressure relief on exhalation.
However, there is often a trade-off between comfort and the most optimal treatment, and that certainly is the case with the distinction between A-Flex and C-Flex. When a CPAP machine's algorithm allows for pressure relief, that of course means the pressure is being reduced. But the very reason we use Positive Airway Pressure in the first place is to have that pressure. So when the pressure is reduced, we are at greater risk for having apneas and hypopneas. On the other hand, if we can't tolerate the pressure without the comfort settings switched on, we will not use the treatment at all, and our machines will become doorstops. A-Flex, one prominent sleep physician told me, is considered the "training wheels" of CPAP therapy because it is the ultimate in comfort settings, and can get people used to CPAP therapy until they are ready to go to the next step, which would be C-Flex. Ideally, though, we'd wean ourselves off both comfort settings, and optimize our treatment in the process.
Most doctors won't tell you about the purposes of these settings, and how to view them in the context of your overall treatment. We at SleepGuide hope you take this information into the total mix of information as you make your CPAP treatment decisions.