Death's door for NPCs and monsters

I posted a poll here on this topic after we discussed it following the last session, if anyone's interested in reading the responses.

For context, here's the official text of the [optional] 2e rule for “hovering on death's door” (DMG p. 75):

You may find that your campaign has become particularly deadly. Too many player characters are dying. If this happens, you may want to allow characters to survive for short periods of time even after their hit points reach or drop below 0.

When this rule is in use, a character can remain alive until his hit points reach -10. However, as soon as the character reaches 0 hit points, he falls to the ground unconscious.

Thereafter, he automatically loses one hit point each round. His survival from this point on depends on the quick thinking of his companions. If they reach the character before his hit points reach -10 and spend at least one round tending to his wounds (stanching the flow of blood, etc.), the character does not die immediately.

If the only action is to bind his wounds, the injured character no longer loses one hit point each round, but neither does he gain any. He remains unconscious and vulnerable to damage from further attacks.

If a cure spell of some type is cast upon him, the character is immediately restored to 1 hit point--no more. Further cures do the character no good until he has had at least one day of rest. Until such time, he is weak and feeble, unable to fight and barely able to move. He must stop and rest often, can't cast spells (the shock of near death has wiped them from his mind), and is generally confused and feverish. He is able to move and can hold somewhat disjointed conversations, and that's it.

If a heal spell is cast on the character, his hit points are restored as per the spell, and he has full vitality and wits. Any spells he may have known are still wiped from his memory, however. (Even this powerful spell does not negate the shock of the experience.)