Do you think you might have pets? Would a mention of them be necessary? How would you want them handled? I see you covered Locked-In Syndrome, which is one of my own fears (I read the book and saw the movie ... and aren't there better technical ways than that today?). You should, of course, amend it if, say, you are in some sort of catastrophic accident of some sort and really hover on the edge of life and death. Would you want a chance to heal and come out of coma? Maybe that's covered in a section with some of the medical jargon I can't fully comprehend.
Edit: Also, I don't know what country you're in, despite the American framing. What about medical expense? How extreme a cost would you expect others -- or yourself -- to bear? Do you have items you would want sold -- say, rare collectibles -- to cover medical costs beyond that you can imagine?