Pre - hydration

Our MDs are becoming increasingly cautious of ordering IV contrast on pts with marginally elevated creatinine levels. We are guided more often by the GFR. This is presenting problems with the consequence of infusing 500 to 1000cc of IV NS in an outpatient setting. Some, who do not give good histories have become overloaded. This adds another responsibility to an area that is supposed to be free flowwing and with rapid turn over. It is wrecking havock with our schedule. We are all being so very cautious of the patient response.
Is anyone else being faced with this?