I'm totally using this idea in my next old school game.
The gist of which is a usage dice.
Instead of making a death save as per your character sheet, you roll a 20. If you get anything other than A 1, you live. However next time you are at deaths door you roll a d12. And so on. I'm going to discuss this my players! My wife though it was cool.
Go and check out the dark age of roleplaying channel