Why not ASV?
An occasional perhaps common critique of our approach to PAP therapy is to achieve the greatest level of comfort for the individual as fast as possible. Anyone who finds PAP comfortable in the first few days of use is not only off to a good start, but also the chances are far greater than 50% (for many close to 90%) that they will become a regular use of PAP. The only caveat is they need to also achieve benefits from use.
CPAP has a terrible track record on both accounts, and sleep doctors clearly point out the process takes a lot of effort. To this day, most sleep professionals witness about only one-third of CPAP users doing great, one-third tolerating something with only partial benefits, and one-third giving up.
So, why would ASV yield different results? Simply, it’s a 1000x more comfortable than CPAP and also delivers benefits more reliably. Sure, you still must find and adapt to the right mask, and learning to wear something all night long to sleep sounds crazy. But it turns out the biggest obstacle to PAP is the intolerance from the sensations delivered by pressurized air.
CPAP delivers fixed air, so when you try to breath out you are still breathing against what for many feels like a tidal wave of air. Breathing in is a relatively easy adaptation but breathing out is where so much of the difficulty lies in using CPAP. This problem is defined as expiratory pressure intolerance (EPI).
When we first published on how ASV eliminates this discomfort we clearly explained that our patients were suffering expiratory pressure intolerance, and the switch to ASV eliminated most of the problem for most of the 56 patients in the study, who by the way were all failing other forms of PAP.
For the next decade, we saw thousands of CPAP failure cases, and the overwhelming majority reported the problem of EPI as the deal breaker. Many of these patients succeeded on bilevel, but at least a third or more needed to move on to ASV.
So if ASV is so much more comfortable and usually delivers benefits faster than CPAP, I continue to ask, “Why not ASV?”