Hi LabCat - I am surprised no one has answered you yet. I begin my new level in my nursing career as a case manager on Monday. I think your question can best be answered by the Case Management Practice page on the Clinical Case Management Certification website:
http://www.ccmcertification.org/pages/13frame_set.html
It gives the theory and description and lays it out pretty well. It's heavily based in the foundations of the Nursing Process, and as I stated to my interviewers, all nurses are case managers in one form or another. This is just doing it full time, away from the bedside. How much I enjoy my work and how much my hands will be tied will remain to be seen, but in theory at least, it seems to be based on what nursing
should be to start with.
Good luck!