In the case of the 80-year-old lady with COPD, if clinical examination suggested that the lady was alert and capable of deciding about whether she would consent to use of mechanical ventilation, I would go by her decision, and discuss this with the daughter and son-in-law. However, a less traumatic mode of therapy called "non-invasive ventilation" is now available, which does not entail inserting a tube into the patient's trachea.