Is It Difficult to Stop a Treatment Once it Has Been Started?

No, not if you have an advance directive and your instructions are clear. Particularly in conditions with a sudden onset, it may take days or even weeks before the reasonable degree of certainty. During the time before the outlook is known, it is appropriate to use any treatments which might be beneficial. When the prognosis is established, if your instructions indicate you would not want continued treatment under the circumstances, treatment can be stopped.