To make sure your wishes are carried out to the letter, you should create your own medical power of attorney. In the document you specify someone to act as your agent. You can grant them all powers you would have or you can limit and or specifically direct the decisions they can make on your behalf.
Pursuant to Probate Code Section 4673 a written advance health care directive is legally sufficient if all of the following requirements are satisfied: (1) It identifies the date of its execution. (2) The advance directive is signed either by the patient or in the patient’s name by another adult in the patient’s presence and at the patient’s direction. (3) The advance directive is either acknowledged before a notary public or signed by at least two qualified witnesses.
There are specific requirements to qualify as witnesses. First , the witnesses shall be adults. Each witness signing the advance directive shall witness either the signing of the advance directive by the patient or the patient’s acknowledgment of the signature or the advance directive.
To eliminate any conflict of interest none of the following persons may act as a witness: (1) the patient’s health care provider or an employee of the patient’s health care provider; (2) the operator or an employee of a community care facility; (3) the operator or an employee of a residential care facility for the elderly or; (4) the agent, where the advance directive is a power of attorney for health care. At least one of the witnesses shall be an individual who is neither related to the patient by blood, marriage, or adoption, nor entitled to any portion of the patient’s estate upon the patient’s death under a will existing when the advance directive is executed or by operation of law then existing.
The legislature has drafted a model power of attorney form that can be customized to meet your needs. You can also Google “Attorney General medical power of attorney California” and locate a PDF that you can customize on line.
I hope this information helps put your mind at ease, your surgery goes well, and you have an uneventful and speedy recovery.