If IV contrast is to be used the patient should remain NPO (not given anything by mouth) for at least four hours. Occasionally to view possible esophageal pathology, patients will ingest oral contrast to help delineate possible mediastinal lymph nodes or gastric tumors. Patients should also remove any metal jewelry or clothing accessories to prevent artifacts from decreasing the diagnostic quality of the images. Certain lab values may be necessary before the scan is undertaken. These would include the BUN (blood uria nitrogen) and creatinine levels to asses the patients renal status. A high creatinine could contraindicate the use of IV contrast as the kidneys are the main organs which excrete the contrast. If a patient is on renal dialysis, then the values are usually higher, and the scan is prior to that day's dialysis treatment.
If the patient received IV contrast, a small bandage will be placed over the injection site, and it should be treated with the same care one would receive after donating blood. Patients should also drink plenty of clear fluids to help flush the iodinated contrast out of their kidneys to prevent any kidney damage.
If the patient is in renal failure then it will be necessary to dialyze the patient soon after the procedure. These arrangements should be made before hand with the knowledge and consent of the consulting nephrologist.
If the patient received any oral contrast it will pass through the GI tract with the next day or two. As the contrast used for CT is much thinner than the standard barium used for GI flouroscopy studies there should be no problems with constipation.
J. Paul Dow Jr., The Gale Group Inc., Gale, Detroit,