An elderly friend of mine was on oxygen to keep him going and was told by a doctor, on one of his last hospital visits, that he would have an unpleasant death, by slow suffocation. He must have asked. Because he was a Christian he felt the need to suffer without strong intervention but I managed to persuade him to have morphine and because he had given me the authority to act for him when he wasn't capable it got stronger so he was peaceful instead of terrified[I hope].
When your lungs fill with fluid and you literally drown, slowly, it's not up there with ways you might hope to die.
