I have a question. How long could someone function with a collapsed lung? My character is a soldier who's been separated from the rest of his brigade on a swampy planet and he has three broken ribs, which have punctured his left lung. Since this is set in the future, I can play with technology a bit, and I've given him three doses of a local anesthetic that he can use to dull the pain if it becomes too much to bear. So, I need to know how long he can go with only one functioning lung.