My state (WI) defines “terminal condition” as an incurable condition caused by injury or illness that reasonable medical judgment finds would cause death imminently, so that the application of life-sustaining procedures serves only to postpone the moment of death.
From Chapter 154, Declarations to Physicians and do-not-resuscitate orders Wis. Stats. Database
The state seems to leave it up to my reasonable medical judgment as to what time frame imminently falls into. Thanks, state! I’ve lost some sleep over that one on a few occasions. But not on most of them, I will admit.