Except, it seems, in Brazil. You learn something new every day

Yes, many. In most cases a trained doctor has a moral, and maybe contractual, responsibility to help some one, not a legal one. There is no law that says ‘you are trained doctor, you have to help fix this broken leg’. Now if you egregiously refuse the various medical licensing authorities might take a dim view and you might loose your license to practice, but that’s not the same as breaking the law