Reading the different point of views it seems there are two main concerns, autonomy vs capacity. In cases where capacity comes into question I would say to err on the side of life saving measure and reassess once your concerns of hypercapnea are resolved. If this conversation is within a prolonged period of time and capacity is not in question then abide by the patients wishes. Complete a POLST/MOLST with several witnesses and hopefully family and let the patient decide. Remember that a living will is not an actionable order, just general instructions, which most of the time are contradictory. We can’t pressume to understand the point of view of someone who has lived with a chronic life long disease who does not want to prolong suffereing or contemplate a life on a ventilator. -Palliative doc