Character A (a doctor) gets injured in an earthquake. Character B--under character A's instruction--needs to perform emergency first aid. I need character A's injury to be serious enough that he can't wait for rescue to get treatment. They're trapped in rubble, and it could be a while before they're dug out. I know anything life-threatening isn't going to have some Magical Cure; I just need something that character B can plausibly do something about, however risky, because he has to in order to keep character A alive.
I've been googling all kind of first aid related terms, trying to find something that fits: "chest trauma," "punctured lung," "first aid," "emergency surgery," etc. The terms are just too broad, and I'm not finding much by way of first aid instructions beyond "cover with a blanket and seek professional medical attention as soon as possible." Ugh.
ETA: Thanks so much for all the ideas, everyone! This place is endless source of information. :)