Even though I was taught in medical school more than 40 years ago that nothing could be done for emphysema and advanced chronic obstructive pulmonary disease, I never accepted that dogma. My beliefs were confirmed when we began to observe the tremendous clinical and physiologic benefits of long-term oxygen therapy delivered by a newly available liquid portable system. Soon, oxygen therapy became integrated into a program of pulmonary rehabilitation. Pulmonary rehabilitation was slow to take hold and was usually carried out in a program supervised by pulmonologists. As controlled clinical trials proved the value of long-term oxygen therapy in increasing ...