CT scans are cited as a frequent source of delay to disposition of our patients in the emergency department. A contributing factor to this delay is the time it takes one to drink their oral contrast and to allow this contrast to travel throughout the intestines. The truth is, very few people actually need oral contrast for their CT.
The American College of Radiology publishes guidelines on the use of contrast agents. Unfortunately, there are no clear recommendations on the specific indications for oral contrast in the most recent published guidelines. The strongest statement in the current guidelines states, “Orally administered contrast media are used for gastrointestinal opacification during routine abdominopelvic CT.”
The emergent CT scan, however, is hardly routine. Several studies have investigated the effect on eliminating oral contrast use in the emergency department. Most studies concluded that eliminating oral contrast use in the ED decreases length of stay no significant effect on diagnostic accuracy. Decreasing ED length of stay has significant implications including an increase in patient satisfaction, reduction in cost, and improvement in the ED environment.
For example, in one of the larger trials, 2,668 patients were underwent CT with IV contrast and without oral contrast after a no oral contrast protocol was instituted in an emergency department over a 12 month period. Thirty seven of those patients returned for repeat imaging during which time they were given oral contrast as well as IV contrast. A changed impression was present in only one of these patients. The one patient with a changed impression had an initial read of possible early appendicitis, however after PO contrast administration the diagnosis changed to ascending colitis as there was good luminal opacification of the appendix by the oral contrast.
The ACR also has a lengthy list of “Appropriateness Criteria” which attempts to address which study would be most helpful for a particular patient presentation. It specifically states that “CT evaluation of the abdomen and pelvis for blunt trauma does not require the use of oral contrast.” In fact, for every indication for CT in the emergency department it gives no official recommendation for or against the use of oral contrast. The only exception is in IBD to assess for fistulating disease as well as possibly for low grade small bowel obstruction.
For now, oral contrast is here to stay and its administration is highly institution and practitioner dependent. If current trends are an indication of things to come, however, we should continue to see less utilization of oral contrast which will further decrease or disposition times.
ACR Committee on Drugs and Contrast Media. Gastrointestinal (GI) Contrast Media in Adults: Indications And Guidelines. In: ACR Manual on Contrast and Media. Version 10.1. New York, NY: American College of Radiology; 2015:57-78.
Levenson RB, Camacho MA, Horn E, Saghir A, McGillicuddy D, Sanchez LD. Eliminating routine oral contrast use for CT in the emergency department: impact on patient throughput and diagnosis. Emerg Radiol 2012; 19:513–517
Lee SY, Coughlin B, Wolfe JM, Polino J, Blank FS, Smithline HA. Prospective comparison of helical CT of the abdomen and pelvis without and with oral contrast in assessing acute abdominal pain in adult emergency department patients. Emerg Radiol 2006; 12:150-157
Razavi SA, Johnson JO, Kassin MT, Applegate KE. The impact of introducing a no oral contrast abdominopelvic CT examination (NOCAPE) pathway on radiology turn around times, emergency department length of stay, and patient safety. Emerg Radiol 2014; 21 (6): 605-13.
Broder JS, Hamedani AG, Liu SW, Emerman CL. Emergency department contrast practices for abdominal/pelvic computed tomography-a national survey and comparison with the American College of Radiology Appropriateness Criteria(®). J Emerg Med 2013;44(2):423–433.