Yes, the requirements are the same as making an Oral Health Care Declaration. A diagnosis of a terminal condition must be made prior to making the oral statement and the statement must be made in the presence of the attending physician and two witnesses. Since the choice of your agent is your most important decision you should chose someone you can trust to make important medical decisions for you. Your doctor can only talk to your agent when you are unable to make your own informed health care decisions. Legally you are unable to make your own decisions when you have a physical or mental disorder which prevents you from communicating or impairs your judgement.
People often confuse the two documents but they really do have different purposes.
The Health Care Declaration is your own personal statement of the life prolonging procedures you would or would not want should you have a terminal condition and are unable to express your treatment preferences. The Health Care Declaration deals solely with life prolonging procedures and applies only if you have a terminal condition. The Medical Power of Attorney covers any situation where you can't make treatment decisions for yourself. It is not limited to life prolonging procedures and you need not have a terminal condition. That doesn't mean you should substitute the Medical Power of Attorney for a Health Care Declaration.