Well, in theory, you can hook some button press, for example IN_USE. Then check if there are incapped persons near you, and then revive them like AtomicStriker does in his pills reviving plugin.
The problem with it, you will get revived instantly even if you taking damage from the horde, making it very hard to takeout several survivors at once, if they are close enough. Would be very imba. Though i think that can be solved with adding few timers. But again it would be imbalanced anyway.