CMS is far from authoritative on what it takes to keep a particular individual under. The practitioner is ultimately the one with authoritative knowledge. CMS is not in the operating theater.

Now if what we need is to deal with a rash of insurance fraud, insurers are more than welcome to hire people to sit in on the theater to gain more representative data. But let's be real here. Insurance is more interested in improving their take home spreadwise rather than improving patient outcomes.

And I beg to differ it doesn't happen. I remember quite vividly my wisdom teeth being extracted. I was just under threshold for being able to do anything about it, but awake and aware for the entire thing. Anaesthesia is not something to screw around with.