The emergency call came in at 10:47 on a Saturday night: "Woman in Overland Park with difficulty breathing. Code one closest."

Angela Fera, a paramedic in Johnson County, Kan., and her partner raced to the house, sirens blaring. When they arrived, six minutes after the first dispatch, a man told them that his 62-year-old wife had terminal cancer and was unconscious. The paramedics found her sitting upright in bed, ghostly pale with a weak pulse and shallow breathing. Death seemed imminent.

The woman was under hospice care and had signed a "do not resuscitate" (DNR) order. She had made her wishes clear: She did not want to be taken to the hospital if a life-threatening medical emergency arose.

But the woman was not in cardiac arrest, the situation specified in the DNR order. Protocol required that Fera try to save her life, probably by inserting a plastic tube into her trachea to restore breathing and transporting her to a hospital, where she'd be put on a ventilator. Fera guessed that was precisely what the woman did not want.

"We were completely fighting all our instincts to jump in and save her, but on the other hand we really wanted to do what was right," Fera recalled.

A new end-of-life document, more explicit and binding than a DNR and advanced directives, is designed to clarify patients' wishes - and spare caregivers such as Fera from facing such wrenching choices.

A "physician order for life-sustaining treatment" (POLST) is a medical order, signed by a doctor or other authorized medical provider. The product of a conversation between patient and provider, a POLST specifies a patient's goals and desires as death closes in.

Without much opposition or attention, many states have adopted POLSTs. They tend to come in garish colors - neon pink, orange and green, for example - so they stand out among other documents in a home. Research suggests POLSTs are effective in matching treatments to patients' wishes.

At the scene of the emergency in Overland Park a year ago, Fera the paramedic had to act fast:

When the woman's children and the nurse arrived, they quickly confirmed that the stricken woman had repeatedly said she didn't want to be revived in such a situation. With that assurance, plus approval via radio from an emergency room doctor, Fera and her partner left the woman at home in the care of the hospice nurse and left.