A 63-year-old man with a history of hypertension and diabetes is brought into the emergency department (ED) by his family. The family has convinced the patient to have his leg evaluated because they have witnessed the condition of his leg worsen over the past week and are concerned about his health. After a thorough history and physical examination, the emergency physician determines that this patient has a cellulitis of his left foot and the inferior portion of his lower extremity. Additionally, he has evidence of a gangrenous left great toe, low-grade temperature, elevation of his white blood cell count, and elevated blood glucose levels. The physician recommends hospitalization for intravenous antibiotics and surgical evaluation for probable amputation of his left great toe. The patient refuses all further care and wants to be discharged from the ED to return home. What should be done?

Every day, with every patient encounter, the emergency physician needs to assess and determine whether patients seen in the ED has the capacity to make decisions regarding their personal medical care. If the patient is alert, communicative, interactive, and comprehends the situation, there is not usually a doubt that he or she has the ability to direct his or her health care. The law presumes that these patients are competent to make decisions about their personal medical care. Patients participate in an informed consent process, whereupon medical evaluation and treatment are agreed on by both physician and patient. At times, a situation occurs that triggers an inquiry into a patient's decision-making capacity. For these situations, determination of the patient's capacity to decide about his or her medical care is extremely important and has significant ethical, moral, and legal implications.