Caring for terminally ill patients can take an emotional toll. The term compassion fatigue was coined more than 20 years ago to describe the effect. But only in recent years have experts begun to create ways to treat and prevent it. A program that began with 14 oncology nurses at Siteman Cancer Center in 2010 is doing just that. This year it will become available to all staff members at Barnes-Jewish Hospital, even housekeepers and security personnel.