ER personnel know this so well that they go to great lengths to ensure it doesn't happen to them
Minor quibble, just saying something like “Promise me if you find me like this that you’ll kill me.” does not constitute 'great lengths'. Depending on tone and context it may not even be meant seriously, and if it is its still not a lot of effort to put towards to goal of not ending up in intensive care.
I'm reposting this from HN's front page, because it brought up a non-cached thought on cryonics:
In short, end-of-life medical care is often pointless, painful and costly; doctors and ER personnel know this so well that they go to great lengths to ensure it doesn't happen to them.
It seems as if our systems and conventions around end of life are designed to not let people have a say in how they spend their final moments, even when letting them have their way would result in significant savings (note the dollar figures quoted above). I've already speculated on why that might be, but I keep seeing that turn up in unexpected ways.
I suspect that this is the bigger obstacle to cryonics, not so much e.g. the lack of scientific proof. "Freeze me cheaply instead of spending insane amounts of money on brutal attempts at keeping me alive" sounds like a sensible thing to tattoo on your chest, but the evidence suggests that it wouldn't be honored any more than "DNR" tattoos.