D&D 5E D&D Next Blog - A Close Call with Negative Hit Points

[UngainlyTitan]

When I've used the Vitality/Wounds option, I've found it to be a bit of a pain in the tuchus, especially when dealing with creatures without a CON score to key off of.

This has been my experience also. In my opinion 4e's healing surge system is a pretty good wounds vitality system and could be used as a basis for something more lethal with a little tweaking. Use surge loss as basis for debilitating effects.
Something along the lines, more than half original surges no major long term effects but reduced surge recouvery. Loose more than half original surge value a penalty to combat effectivness and slower surge recouvery.
No surges, seriously wounded needs immediate hospital care for the next 6 months or so.