A Do Not Resuscitate (DNR) order tells medical professionals that you do not want them to utilize any aggressive measures to save your life. Medical care itself is fine, but if you pass away, you want them to stop short of attempting to bring you back. This can be an important part of your estate planning, along with documents like a health care advance directive.
If your spouse passes away, you know you may have some big financial decisions to make. This could include doing substantial estate planning to alter the plan in light of your new situation.