Objective: Most diagnostic imaging centers ask patients to fast for 4-6 hours before contrast-enhanced CT. Previous studies have shown that prolonged fasting can be harmful. In addition, manufacturers of contrast agents claim that there is no special preparation needed before examination. The aim of this study was to evaluate the effects of preparative fasting on contrast-enhanced CT at a cancer center.
Subjects and methods: Outpatients (n = 3206) were prospectively evaluated and randomly assigned to two groups: the 1619 patients in group 1 fasted for at least 4 hours before the examination, whereas the 1587 patients in group 2 received a light meal. Adverse symptoms observed before and after contrast agent administration were compared between groups.
Results: Adverse symptoms occurring after IV contrast agent administration were reported by 45 patients (1.5%) in group 1 and 30 patients (0.9%) in group 2. The most common symptoms were nausea (n = 32), weakness (n = 12), and vomiting (n = 5). The frequency of symptoms did not differ statistically significantly between groups (p > 0.05).
Conclusion: In this sample of patients with cancer undergoing contrast-enhanced CT, very few adverse symptoms were reported regardless of preparative fasting. These results support the idea that preparation for contrast-enhanced CT can be simplified, decreasing the discomfort and inconvenience experienced by patients.
Keywords: CT; cancer; contrast media; outpatients; preparative fasting.