This is the title to a recent New York Times health blog post. (You need to register to read it, but it is free.)
The author recounts her experience with her family trying to deal with her grandfather's illness and their attempts to interpret his wishes about the end of his life. She writes:
...the experience made me realize that having a living will isn’t enough — we need to be sure that we have been clear and specific, and that we have considered a variety of scenarios as we try to instruct our loved ones to make decisions for us in a medical crisis. Phrases like “terminal illness” are vague at a time when new treatments and drugs can keep patients with a terminal disease alive for months or years.
Many people prepare a "Living Will" or "Life Support Statement" as part of their estate plan. As the author indicates, these documents are sometimes filled with vague statements about death being a natural part of life, and "heroic measures", which can make it difficult for your family to interpret in their time of grief.
I explain to my clients that even if they sign a Living Will, it is very important that they also have conversations with their loved ones about the different types of situations that can arise and what they might want done in those cases. These conversations do not need to be a big, formal, one-time thing. They can occur if something is in the news about end of life care, or if a friend or relative is going through something similar. It can be easier for your family to remember this way - "Oh, I remember when Aunt Peg was in the final stages of breast cancer, mom said she wouldn't want another surgery if that happened to her."
The Mayo Clinic also has a great guide for discussing your last wishes. It outlines the different treatments that you'll want to address: resuscitation, mechanical ventilation, nutrition and hydration assistance, dialysis and treatments at the end of life. It also reminds you to revisit your wishes from time to time to see if they change - for instance during pregnancy or if you are diagnosed with a terminal illness.