Contrast Reactions:
Everyone feels a sense of warmth or flushing during contrast administration - this is not an allergy.
For known contrast sensitivity (e.g., hives, rash), consider prednisone, 60 mg PO q6h x 4, prior to exam. Benadryl, 50 mg PO can also be added.
Alternatively consider using prednisone, 60 mg PO q12hrs prior to procedure, then take diphenhydramine, 50 mg + Cimetidine, 300 mg + prednisone, 60 mg when on call to the procedure.
Ensure that the contrast is non-ionic contrast, especially if the Pt has had a major event with previous contrast administration.
Contrast used in MRI is gadolinium prep. It is highly unusual for a patient to have an allergy to gadolinium.
IV hydration and Mucomyst, 600 mg PO bid prior to procedure may also be added in renal insufficiency
Contrast should not be given to anyone with a Cr >2
Contrast Nephropathy Tx :
Isotonic NaHCO3, 3 mL/kg bolus x 1 h, followed by 1 mL/kg/h x 6 h.
Mucomyst (N-acetylcysteine), 600 mg PO bid the day before and the day of contrast.
Stop metformin an NSAIDs before procedure.
Evidence for these prophylaxis is not strong.
Fluid hydration is key.