A 72-year-old patient with advanced dementia is admitted with pneumonia. The patient's durable power of attorney for healthcare is her son, who insists on full aggressive treatment, including intubation and mechanical ventilation, despite the medical team's assessment that such interventions are unlikely to improve her prognosis and would prolong suffering. Which ethical principle is primarily in conflict in this situation?

The correct answer to the question "A 72-year-old patient with advanced dementia is admitted with pneumonia. The patient's durable power of attorney for healthcare is her son, who insists on full aggressive treatment, including intubation and mechanical ventilation, despite the medical team's assessment that such interventions are unlikely to improve her prognosis and would prolong suffering. Which ethical principle is primarily in conflict in this situation?" is Option D: Non-maleficence..

The other options — A) Justice., B) Beneficence., C) Autonomy. — are incorrect for this USMLE Exam Prep question. As explained above: Non-maleficence, 'do no harm,' is in conflict when aggressive treatments are pursued that are unlikely to benefit and may increase suffering, even if requested by a surrogate decision-maker.