Pulmonologist here. I am also the medical director of a hospice for the last 15 years. First, I am very sorry for the difficulty that you, your father, and your family are having to deal with. As a physician, and particularly in doing pulmonary/critical care as well as hospice, I have tried to help people through these tough situations for most of my career. Each case is individual and each patient is an individual with their own beliefs and values and dreams.Over the years, I've spoken to many dying patients and their families about their illness, and what I've tried to do is to give them the perspective of a physician in order that they can then use their own values and beliefs within the framework of a physician's perspective...using what we know and applying their own perspective.As a physician, my perspective on your father is that he is dying. Please don't take that as callous...it is not meant that way. Most people think of dying as a moment...and it certainly can be...car wreck, heart attack, massive stroke... those thinks can take a life in the blink of an eye. However, for many, if not most, people...dying is a process. It can be several hours or several weeks...or longer It begins when you know that nothing else can be done for the patient and all you are trying to do is maintain, and despite your best efforts, the trend is that the patient continues to decline. All patient's have good days and they have bad days, but for a dying patient, when you average it out, the trend is that they continue to worsen.It's at this point that I think it's important to find out what kind of death your father really wants. That can sound very brutal to some people...but remember, we're physicians and we experience this life and death everyday, and we see patients who die peacefully and comfortably and we see patient's who die alone and in horrible circumstances. With those experiences in mind and with our practicality, we begin to think about what we would want for ourselves. Ask any physician or nurse friend of yours...chances are they've thought about it a lot...far more than other people. They tend to know exactly how far they're willing to go before they just want comfort.From your post, you've spoken to your Dad about his care:He's expressed that no matter how small the chance is, he wants to continue fighting. We've had this talk serveral times throughout the years. Even now he expresses this. Which is why I'm trying to explore every realm of possibility.When he says "chance," what does he mean? Chance of a cure?...chance to go back home?...chance to get a little better and be off the ventilator? In other words, you need to know what his goals are. If his goal is cure, there is no chance. If his goal is going home to the way his life had been...there probably is little chance of that either, though there may be a chance to go home...I don't have enough information. But first, find out which of his goals are potentially achievable with his doctors. Once you know what goals are potentially achievable for your father, you and his doctors can talk about what would have to happen to achieve those goals.Eventually...at some point however, because of the nature of our existence, none of those goals will be achievable, and at that point it is reasonable to give your father permission to let go and to seek comfort in the final moments, days, or weeks of his life. I say that because many patients continue to fight because they think that's what they're suppose to do or because they think they'll be letting down their family if they let go. They endure unnecessary suffering because no one has offered them a path of comfort and acceptance or because they made a vow to fight on and they don't want to renege on a promise they made to someone.We all eventually die. Some of us will never know what hit us because it comes too quickly. For those of us who are struck with a terminal illness like cancer, the only benefit is that we may have enough time to get our personal affairs in order and make peace while having some control over the dying process. As a physician, I know how I'd want to die, however, I don't try to push that on any of my patients. There are definitely patients who don't want to do much at all and just want to enjoy what life they have left. There are other patients who can't die in peace without trying everything including investigational treatments. I respect them all but as a physician I have to make sure that they are making those decisions knowing all the facts and the possibilities and risks.Start by talking to your father about his goals and discussing those goals with your father and his doctors. Give your father permission to do what he wants whether it's letting go or fighting to his last breath. And make sure that in the end, his comfort and wishes guide what decisions you may have to make in his stead. I hope this helped a bit. As best as I can on a reddit post, I'd like to give you, your father, and your family a big hug and my wishes that you all will be comforted in the days ahead.
Another aspect to note is that patients who see palliative care earlier have a much better prognosis - longer survival times and higher quality of life scores.