Not long after complaining of shortness of breath at her Quinlan home, Patricia Cannon was in a Hunt County ambulance heading north toward Greenville with a drug dripping into her veins capable of paralyzing every muscle in her body.The drug, succinylcholine, was administered by a paramedic. The intent was for Cannon, thought to be suffering from a blood clot in the lung, to be immobilized while a breathing tube was placed in her windpipe.But something happened along the way that prevented the tube from being inserted correctly. The job wasn't done until the ambulance delivered Cannon, 41, to the emergency...