Here is what I said in an earlier discussion of this topic:
I considered going into both anesthesia and emergency medicine but chose to do an emergency medicine residency. During my residency I identified a number of issues with the specialty which I could not resolve. Thus, late in my residency as my fellow residents sought employment I searched for residency positions in anesthesia. What amazed me is that none of my established attendings tried to change my mind. When I discussed with them why I was choosing this path they agreed that this was a wise decision for me.
I have friends who continue to practice Emergency Medicine and seem to enjoy it. If you have the right personality, EM could be your field. In many ways Anesthesia and EM are similar. Both specialties require that you be able to quickly interact with a patient and identify pertinant historical and clinical features that apply to your management plan.
Things I dislike about emergency medicine:
The shift-work mentality does not build professional respect
Most of your working hours are during afternoons, evenings, weekends
holidays, etc. (I used to be away from home 16-18 nights/month)
Spent alot of time talking to people on the phone
Spent alot of time waiting for other people to do things (consults,
returns pages, admit pt, etc.)
Most of time is spent seeing stuff that could/should be seen in clinic
Rarely see a critically ill patient (the type of case that draws people to
the specialty)
Production pressure ("move the meat")
As an EP you are not a "specialist" in any discipline of medicine,
despite what you may think
The nature of the work is stressfull. The multi-tasking is comparable
to being an air-traffic controller or bonds trader
I rarely did procedures, despite being at one of the busiest ER's in the
country (>110,000 visits a year)
Things I like about Anesthesis:
You get to be an expert in a specialty
You get to see an effect from your actions (pharmacology,
physiology, critical care in action)
Better hours (Quality not Quantity)
More procedures
Better interactions with patients and physicians
I do not regret my training in Emergency Medicine. I achieved board certification but chose not to practice. My training was excellent preparation for anesthesia (much better than 1 year of transitional/medicine rotations). I can not recommend that those considering both fields follow my path. That would require 6-7 years of residency training.
The best thing you can do to assist your decision is to talk to as many practicing physicians in both fields as possible. This means trying to talk to those in the community as well. (Don't limit your discussions to the academic practioners alone.) Go shadow a community hospital EP or Anesthesiologist for a few days if you can. Do an elective in either specialty in a non-academic environement. Think deeply about what type of personality you have, what brings you professional fulfillment, and how you want to spend your professional time. Hope this helps.