California Probate Code
Sec. § 4733


Except as provided in Sections 4734 and 4735, a health care provider or health care institution providing care to a patient shall do the following:

(a)

Comply with an individual health care instruction of the patient and with a reasonable interpretation of that instruction made by a person then authorized to make health care decisions for the patient.

(b)

Comply with a health care decision for the patient made by a person then authorized to make health care decisions for the patient to the same extent as if the decision had been made by the patient while having capacity.
Source
Last accessed
Jun. 6, 2016