3.1 Medical Ethics & Patient Autonomy

Core Principles of Medical Ethics

Medical ethics on the USMLE Step 3 is highly clinical, testing your ability to apply core ethical tenets to complex, real-world bedside dilemmas. The four fundamental principles of biomedical ethics—autonomy, beneficence, non-maleficence, and justice—provide the primary framework.

• Autonomy represents the patient’s right to self-determination. A patient with decision-making capacity has the absolute right to accept or refuse any medical treatment, even if that refusal leads directly to death. Autonomy almost always triumphs over beneficence when a patient is capacitated.
• Beneficence requires the physician to act in the best interest of the patient. This involves actively promoting the patient's well-being and balancing the benefits of an intervention against its risks.
• Non-maleficence is the obligation to do no harm. In practice, this requires clinicians to avoid treatments that offer no benefit or whose harms outweigh any potential benefits (e.g., performing unnecessary surgery).
• Justice demands the fair and equitable distribution of healthcare resources. It dictates that similar patients receive similar care regardless of socioeconomic status, race, or ability to pay. On the exam, justice questions often involve allocating scarce resources (e.g., triage protocols or organ transplant lists) without bias.

Determining Decision-Making Capacity

Determining capacity is a clinical assessment performed by the treating physician for a specific decision at a specific time. It is distinct from competence, which is a legal term determined solely by a judge. A patient can be legally incompetent (e.g., due to severe chronic cognitive impairment) but still retain the clinical capacity to make simple decisions. Conversely, a legally competent adult can temporarily lose clinical capacity due to acute delirium, drug intoxication, or severe pain.

To establish decision-making capacity, the clinician must document that the patient meets four criteria:

1. Communicates a clear, consistent choice: The patient does not vacillate or change their mind repeatedly when presented with options.
2. Understands the clinical information: The patient can state the nature of their diagnosis, the proposed treatment, the risks, benefits, and alternatives (including no treatment).
3. Appreciates the clinical situation and its consequences: The patient understands how the information applies directly to their own life. For example, a patient refusing a life-saving blood transfusion must appreciate that this decision will result in their death.
4. Engages in rational reasoning: The patient can explain why they are choosing a specific option, demonstrating a logical connection between their values and their choice. The decision does not need to align with the physician's values, but the reasoning process itself must be intact.

If capacity is impaired (e.g., by acute delirium), the physician must first attempt to treat the underlying cause (such as infection or electrolyte imbalance) to restore capacity before making major decisions, unless the situation is an immediate emergency.

Advance Directives and Surrogate Decision-Making

When a patient lacks decision-making capacity, the physician must look to advance directives or identify a surrogate decision-maker.

• Durable Power of Attorney (DPOA) for Healthcare / Healthcare Proxy: This is a legal document in which a patient designates a specific agent to make medical decisions on their behalf if they lose capacity. The DPOA has the highest authority among non-judicial decision-makers. They can make decisions not explicitly mentioned in a living will, guided by their understanding of the patient's values.
• Living Will: This document outlines the patient's specific instructions regarding life-sustaining treatments (e.g., mechanical ventilation, artificial nutrition, cardiopulmonary resuscitation) in the event of terminal illness or persistent vegetative state. A living will is narrower than a DPOA. If a conflict arises between a DPOA's decision and a living will, the DPOA’s decision generally takes precedence, as the DPOA is expected to interpret the living will in the context of the active clinical scenario.
• Surrogate Decision-Maker Hierarchy: If no DPOA exists, the physician must identify a surrogate from a state-defined hierarchy, typically: spouse, adult children, parents, adult siblings, and then other relatives.

Surrogates are legally obligated to make decisions based on substituted judgment—meaning they must choose what the patient would have chosen for themselves, rather than what the surrogate wants or what the surrogate believes is best. If the patient's wishes are entirely unknown (e.g., a patient who was never capacitated or never discussed their wishes), the surrogate must use the best interest standard, selecting the option that a reasonable person would choose to minimize suffering and maximize benefit.

DNR/DNI Orders and End-of-Life Dilemmas

Do Not Resuscitate (DNR) and Do Not Intubate (DNI) orders are medical orders written by a physician, not the patient. While they must align with the patient’s expressed wishes, they are distinct from living wills. A DNR order applies only to cardiopulmonary arrest; a DNI order applies only to respiratory failure requiring intubation. Having a DNR/DNI does not mean "do not treat"—patients should still receive full medical therapy, pain control, and surgical interventions if appropriate, up to the point of cardiopulmonary arrest or respiratory failure.

Clinical Futility: If a treatment is physiologically futile (e.g., CPR in a patient with multi-organ failure on maximum pressor support where resuscitation cannot restore cardiopulmonary function), the physician is not ethically obligated to perform it. However, unilaterally writing a DNR order is ethically and legally sensitive. The physician should hold multidisciplinary family meetings, clarify goals of care, consult the hospital ethics committee, and, if necessary, offer to transfer the patient's care to another provider before acting unilaterally.

Refusal of Care by Adults: An adult with decision-making capacity has the right to refuse any medical treatment, including life-saving interventions. The classic example is a Jehovah’s Witness patient refusing a blood transfusion. If the patient is an adult with capacity, their refusal must be honored. In an emergency where an unconscious patient's Jehovah's Witness status is suspected but not documented (no wallet card or family verification), the physician must perform the transfusion, prioritizing the preservation of life until clear documentation or a surrogate is available.