This is one of those questions that is really hard to answer. There are so many factors that determine a translator salary, whether the translator works freelance translation jobs or works as a translator in a hospital.
Bigger hospitals will probably have bigger budgets with which to pay translators, while this won't be the case in smaller rural hospitals.
Sorry I can't be more specific, but I think that a translator can earn a decent living from working in a hospital but there are too many factors involved.
