[Relationship between oral food intake and nausea caused by intravenous injection of iodinated contrast material]

From December, 1990 to July, 1992 we investigated the relationship between the time after oral food intake and nausea and vomiting caused by the intravenous injection of iodinated contrast media in 2,414 patients who underwent contrast enhanced CT. The contrast media used were as follows: amidotrizoic acid (high-osmolality contrast medium, HOCM, iodine 292 mg/ml) in 1173 patients, iopamidol (low-osmolality contrast medium, LOCM, iodine 300m g/ml) in 641 patients, and iohexol (LOCM, iodine 300 mg/ml) in 600 patients. All the patients had an intravenous injection of 100ml in volume. The overall incidence of nausea and vomiting was 3.8% (96/2412 patients). The incidence was 6. 7% (79/1173 patients) in the HOCM group and 1.4% (17/1241 patients) in the LOCM group. The incidence of nausea and vomiting increased with the interval between the oral intake of food and the intravenous injection of contrast medium. It is concluded that fasting before contrast-enhanced CT enhances the adverse effect of nausea and vomiting.