You will get calls about an unconscious man, or one man in a fight has a knife in his belly, there was also one about a construction injury, but I don't remember the details on that one.
The unconscious man ones, you might find that he's not breathing and you can instruct the caller to do CPR, then wait for paramedics.
The knife in belly, have the caller leave the knife in, and dress it with something then wait for paramedics.
I'm sure there are more, these are just examples