Obviously, your assessment skills are paramount. As are critical thinking skills as realted to fluids and electrolytes. Certainly cannulating skills, the occasional subQ injections, Tuberculine PPD, some outpatient clinincs still hang blood. CHF knowlege is a biggie since your dealing with great potential for fluid overload, then of course the drops in bloodpressures.
Skills pertaining to central lines, dressing changes, blood draws.... those are just some for starters. I'm sure others will add to the list.