I will be interested to hear the response as well, although I think Laurie may mean that most people with ALS will, at some point, experience respiratory insufficiency. I am not an RT, so I cannot adequately discuss this (again, maybe Diane as an RN will comment), but for instance, my husband definitely has respiratory compromise (limitations), is easily taxed, and I believe is experiencing mild to moderate respiratory insufficiency at times when eating. I believe he is at times experiencing "oxygen debt", eventhough his O2 levels are often adequate (above 90%) when measured by our home pulse oximeter. He is, however, "stable" in that his condition has not exhibitted a sudden change in respiratory rate, dramatic use of accessory muscle breathing (seen in the neck and upper chest muscles) or blueish color of his lips. The question for me is, how long do I watch this before I / we decide that his fairly "stable" respiratory compromise turns into something much worse. As Diane pointed out in her very helpful and detailed response, someone who already has significant respiratory compromise is much more likely to die of aspiration pneumonia, the flu, or even a bad "chest cold".
Brad, my understanding of one of the biggest challenges of having a tracheostomy is that your body will fight the stoma. How much is largely unknown, and it is probably different from one person to another, but an unnatural orifice has been created in your larynx. Your body's natural reaction will be to try to heal it/close it, and of course this is being prevented. Also, almost every patient that I have ever known who still had the plugged trach and Passy-Muir Valve has struggled with a copius amount of secretions/mucus. If you already have that, then maybe it won't be much of a change for you. In my husband's case, he has very minimal bulbar issues at present, so I think that the adjustment to the healing process/copius mucus production would be very stressful for him.