I'm going to read into your word choice a bit, and guess that you're equating "adventure" with "combat." I hope your DM includes more in his adventures than just combat; that would be horribly boring.
Sure, you can go shopping for new clothes the whole game if that is more interesting.
Some people in this thread have noticed that players become more cautious when they don't know what their hit points are, exactly. I'd expect the same result from "death spiral mechanics." Your preference is obviously your own, but I would actually like to see both rules in a game - it sounds like it would be incredibly gritty and intense.
It maybe gritty and intense but it is not very DnD. Sounds more Rolemastery to me, maybe CoC if you just want players to be more cautious going up against creatures that can insta-kill you given half a chance.