Hemodialysis should be withheld in this patient who has refused treatment. Patients have the right to refuse any treatment, including those that are life prolonging. A patient's decision to refuse life-prolonging treatments is not necessarily irrational; rather, it is often based on the patient's health care values, goals, and preferences in the context of the perceived benefits and burdens of the proposed treatment. In these cases, the physician's duty is to understand the rationale for the decision and ensure that it is informed. This patient has provided informed refusal for hemodialysis, and her decision should be respected.

A psychiatric evaluation is not necessary in this case because the patient has demonstrated all three elements of decision-making capacity: understanding of her current situation, understanding of the risks and benefits of her decision, and the ability to communicate her decision. In addition, her decision appears well aligned with her underlying beliefs. Psychiatrists may be helpful in determining decision-making capacity in situations in which there is a question about the patient's ability to make decisions or apparent misalignment between the decision and underlying beliefs. Additionally, a psychiatrist cannot determine if a patient is competent, as this is a legal decision made by the courts.

If a physician begins or continues a treatment that a patient has refused, the physician, regardless of his or her intent, is committing battery. Overriding this patient's refusal of hemodialysis is unethical and illegal.

There is no evidence that this patient lacks decision-making capacity; therefore, there is no need to refer to the patient's advance directive and ask the son to make a decision regarding his mother's hemodialysis.