An assessment of repeat computed tomography
utilization in the emergency department in the setting of blunt trauma
Michael J. Burla
Jeffrey S. Ditkoff
David A. Berger
Received: 24 January 2018 /Accepted: 23 May 2018
American Society of Emergency Radiology 2018
Purpose Computed tomography (CT) is a standard imaging modality utilized during the evaluation of trauma patients in the
emergency department (ED). However, while it is common to utilize intravenous (IV) contrast as an adjunct, the use of multiple
CT scans and how it impacts patient flow can lead to changes in patient management. Our objectives are to assess length of stay
(LOS) and rates of acute kidney injury (AKI), when two CTscans of the abdomen/pelvis are performed compared to one CTscan.
Methods Data of trauma hospital encounters were retrospectively collected during a 5-year period at a large, level 1 trauma
center. Encounters were categorized into patients who received one or two CT scans of the abdomen/pelvis, as well as if they had
received IV contrast or not. CT scan reads were extracted from chart records, and groups were compared.
Results Of 5787 patient encounters, 5335 (93.4%) received IV contrast and 75 (1.3%) received two CT scans. Lower rates of AKI
were associated with IV contrast (2.5 vs 12.5%). Receiving two CT scans was associated with increased rates of AKI (20.0 vs
3.0%; p < 0.0001), ICU admissions (88.0 vs 25.1%; p < 0.0001), and hospital LOS (21.9 vs 1.4 days; p < 0.0001). Of the repeat
CT scans, 59.4% demonstrated no significant difference and did not require blood products or the operating room.
Conclusion Two CT scans performed during blunt trauma encounters demonstrated mixed benefit and were associated with an
increased hospital LOS. Additionally, IV contrast was associated with lower rates of AKI.
Keywords Blunt trauma
Length of stay
Injury severity score
Computed tomography (CT) is a standard imaging modality
utilized during the evaluation of blunt trauma in the emergen-
cy department (ED) [1, 2]. While the use of CT scans has
improved diagnosis and decreased hospital admissions in
these settings [2–5], CT utilization varies between institutions,
including the role of intravenous (IV) contrast as an adjunct
. While IV contrast can increase sensitivity of evaluating
trauma injury in blunt trauma patients, it may play a role in
acute kidney injury (AKI) [7–9] and may not be of benefit in
patients receiving multiple CT scans. Patients receiving IV
contrast with multiple CT scans in any given visit may have
an increase in morbidity and increase their hospital length of
stay (LOS). For these reasons, it may be beneficial to stratify
this patient population to determine which patient populations
are at higher risk for requiring intervention.
There are multiple validated scoring systems which clini-
cians can utilize to risk stratify trauma patients [10–14]. One
tool that is routinely utilized and collected by the National
Trauma Data Bank (NTDB) is the injury severity score (ISS)
. Studies have shown that increased ISS values have been
shown to be a predictor of outcomes in trauma patients .
Furthermore, higher ISS values tend to be associated with
intensive care unit (ICU) admissions  and is an indepen-
dent predictor of contrast induced nephropathy (CIN) .
Previous clinical practice has also implied concerns of IV
contrast alone leading to AKI , especially in patients with
lower estimated glomerular filtration rate (eGFR) .
However, recent literature has demonstrated that IV contrast
alone is not associated with increased rates of AKI [8, 9, 19],
although these patient populations were not specific to trauma
encounters. Given that all of these studies were retrospective,
* Michael J. Burla
Department of Emergency Medicine, William Beaumont Hospital,
Royal Oak, MI, USA
Oakland University William Beaumont School of Medicine,
Rochester, MI, USA