In three single-center, randomized trials, oral contrast — given in addition to intravenous (IV) contrast — did not improve the diagnostic accuracy of computed tomographic (CT) scanning for suspected appendicitis. To determine whether this conclusion is generally valid, researchers analyzed a surgical database that represents 56 hospitals in Washington State. During a 2-year period, 8089 adults underwent nonelective appendectomy preceded by CT scanning; 54% received IV contrast only, 29% received both IV and enteral contrast, 13% received no contrast, and 4% received only enteral contrast.
Concordance between CT scan interpretations and pathology reports was 90% in both the IV-only and IV-plus-enteral contrast groups; concordance was slightly lower (86%) among patients who received no IV or enteral contrast. Accuracy of the two CT protocols remained similar after adjustment for potentially confounding variables and in a propensity-matched analysis. Accuracy was similar in all types of hospitals (urban or rural; teaching or nonteaching).
Drake FT et al., Ann Surg 2014 Jul 260:311. Link.