Potential harmful effect of iodinated intravenous contrast medium on the clinical course of mild acute pancreatitis

Hypothesis: A worse clinical outcome might be expected in patients with acute pancreatitis (AP) who receive intravenous contrast medium for a nondynamic contrast-enhanced computed tomographic (CECT) study early during hospital admission. Design: Cohort analytic study. Setting: Tertiary care center. Patients: Of 126 patients with mild AP, 52 patients underwent CECT to establish AP diagnosis (group 1), and the remaining 74 did not (group 2). Main Outcome Measures: Survival and development of local or systemic complications during the hospital stay. Potential confounders were demographic, clinical, and biochemical data, as well as therapeutic measures. The Atlanta classification was used to define local and systemic complications. Results: Mean age, etiology of AP, prognostic score on admission, and pharmacologic treatment were similar between groups. Local and systemic complications were more frequently observed in patients who underwent CECT (odds ratio, 11.4; 95% confidence interval, 2.0-64.8; P=.008). Six patients, all in group 1, developed a pancreatic abscess (odds ratio, 20.8; P=.004). In 5 of them, a second CECT showed more severe Ar changes. The association between CECT and abscess development was more apparent in patients with a body mass index of 25 or more and/or nasogastric suction. Six patients in group 1 and 1 in group 2 had systemic complications (odds ratio, 9.5; P=.01). There were no deaths. Conclusions: The observed increased incidence of local and systemic complications in patients with mild AP who undergo CECT, particularly in those with a body mass index of 25 or more, suggests a potentially harmful effect of intravenous contrast medium. Until this issue is clarified, it stems reasonable to restrict the use of dynamic CECT to patients with severe AP, protracted clinical course, or suspected local septic complication.