EM residencies are three to four years long, depending on the program (but most are three). I suppose that trauma surgery might be included as a "rotation" in EM, but EM doctors don't do surgery routinely.
To be in trauma surgery, I think you go through a few years of general surgery and then do a fellowship in trauma surgery. You wouldn't start out in EM.
EM is a great field. You don't have to worry with your own practice, the hospital generally covers your malpractice insurance, you have other great benefits, there's no call, hours are somewhat flexible, and you're well compensated.
However, many of the patients are drug-seekers, self destructive, etc. You see a lot of the same thing from day to day, I would expect. It's not nearly as fast-paced as "ER" or "Trauma: Life in the ER" portrays. I shadowed the other day in the ER and one of the med students said that she had been there for two or three weeks on her rotation and she had only seen two major resucitations (sp?) the entire time.
But I would say that would be different in a residency. Most residency programs I would assume would be in large trauma centers (as opposed to the semi-rural ER I shadowed in) and therefore would have a larger patient load and more acute cases. For example, I was looking at UofL's EM residency and their website's movie said they had one major resucitation every day.
Hope this helps...