What exactly does a case management nurse do?

It depends upon where you are working... CM's work in a variety of locations. Insurance companies, Work Comp, hospitals (acute care), etc. My hospital requires a Master's for us to be CM's. I do dismissal planning, which requires an assessment on the front end of support systems, current equipment owned, where pt lives, if they live alone, etc. I also do concurrent review with 3rd party payors. We chart using computer, with a program purchased by our hospital for CM's only. It has beena blessing and a bane. We also are required to see our patients daily, and document the ongoing dc plan of care. I also provide info to Work Comp providers, and set up OP follow-up such as home health, hospice, or therapies.