Yes. An advance directive may be used to manage your health care while you are still living.
An advance directive is a document in which a person appoints a "Health Care Representative" to make medical decisions such as living arrangements and treatment options when they become incapacitated and unable to make their own decisions. An advance directive can be used to indicate whether you wish to have life support, tube feeding or other measures when you are close to death.
An advance directive can be an excellent end-of-life planning tool. It expires at death, or can be revoked at any time.