If you ended up unconscious and on life support, how long would you want your family to wait and see whether you recovered? If you want to make sure your wishes are respected, consider an advance medical directive.
An advance medical directive lets you indicate who you wish to make decisions for you if you cannot make them for yourself. It also usually includes information to guide that person. For example, you’ll have to wrestle with some questions like: at what point you would consider your life not worth living? Some of the types of paperwork you may want to fill out — which may be separate documents — include:
A living will, to indicate what care you would and would not like at the end of your life
A substitute decision-maker, designating a certain person to make decisions for you
A do-not-resuscitate order, if you do not wish to be resuscitated. This typically needs to be on your medical chart and/or signed by your doctor. Each state and territory has its own form that must be filled out. For example, NSW Health offers a Resuscitation Plan which is a medically authorised order to use or withhold resuscitation measures.
To find the appropriate paperwork, google “advance medical directive” and your state or territory. While it’s not always necessary to use a particular form, each state has requirements about what makes a directive valid. (Your hospital may also be able to help you file the appropriate paperwork.)
Even though you can fill out the forms ahead of time, the documents are not totally legally binding. Sometimes doctors are allowed to ignore your wishes (if you are pregnant, for example.) Even when things go according to plan, your doctors and family are the ones who get the final say in the end, so the most important thing is having some honest conversations with them so they understand your wishes.
This FAQ page from Advance Care Planning Australia does a good job of explaining the basics, including the laws and regulations you need to be aware of in each state and territory.