I do 14, 12-hour in house ICU shifts/month (Our ICU model has moved to 24/7 coverage). For the time being I do NO EM, but can pick up PRN. I'm at an academic hospital with 800ish beds and a little over 100 ICU beds, I currently work only in the MICCU (36 beds, with 12 being a pulmonary step-down).
You can do both, but most people gravitate towards one or the other. I have no interest in low risk abdominal pain, low risk chest pain, vaginal discharge as a chief complaint, back pain etc.. so Id need to only work on the resus side to maintain interest which the director told me we could work out.