Risk and Benefit of Intravenous Contrast in Trauma Patients with an Elevated Serum Creatinine Lorraine N. Tremblay, MD, PhD, Homer Tien, MD, Paul Hamilton, MD, Fred D. Brenneman, MD, Sandro B. Rizoli, MD, PhD, Philip W. Sharkey, BS, Peter Chu, MD, and Grace S. Rozycki, MD Objective: Assess if the benefits out- weigh the risks of intravenous (iv) contrast in trauma patients who present with an elevated serum creatinine (Cr). Background: Radiologic investiga- tions with iv contrast are often used in trauma patients to rapidly assess for life threatening injuries. However, contrast nephropathy (CNP) is associated with in- creased morbidity and mortality. This poses a dilemma for the physician who must weigh the risks and benefits of pro- ceeding with iv contrast versus the risks of missed injuries/delayed diagnosis. Methods: A 2 year (2002–2003) ret- rospective chart review of all trauma pa- tients presenting with an elevated Cr(>1.3 mg/dL or >115 mol/L). Results are mean  sd (p < 0.05 significant). Results: Ninety-five patients (age 51  23 years; ISS 31.7  15.6; hospital stay 29  32 days; mortality 9%) presented with a Cr > 1.3 mg/dL (31 with Cr >1.7; 3 dialysis dependent). Fifty-six (59%) were given iv contrast (C), of which only 2 (3%) had a transient rise of 25% in Cr within 48 hours versus 6 (16%) patients not exposed to contrast (C). No C pa- tient developed CNP requiring longterm dialysis. Of the 56 undergoing C tests, 16 had injuries requiring urgent intervention identified; 16 had injuries that were man- aged nonoperatively, and 24 had serious injuries ruled out. Of the 39 C patients, 9 had indeterminate CT’s; 2 had missed injuries; and 2 had no intraabdominal in- juries found at celiotomy. Conclusion: This study suggests the benefits may outweight the risks for pro- ceeding prn with iv contrast in trauma patients with an elevated creatinine. A larger study is needed to confirm these findings. Key Words: trauma, intravenous contrast, renal failure, contrast nephrop- athy, outcome J Trauma. 2005;59:1162–1167. R adiologic investigations using intravenous contrast have become a mainstay in the assessment of the severely injured trauma patient. 1–3 In particular, the modern multi-slice computer tomography (CT) scanner has become the investigation of choice to rapidly assess whether major vascular or other life threatening internal injuries are present; and if so, whether nonoperative man- agement or urgent surgical or angiographic interventions are required for active contrast extravasation. All contrast studies however carry a risk of contrast nephropathy. 4 While the precise definition of contrast nephropathy is somewhat controversial, most studies define it as an sig- nificant increase (0.5 mg/dL or 25%) in serum creat- inine within 48 hours of administration of contrast dye. Contrast nephropathy is associated with increased morbid- ity and mortality during hospitalization, and can lead to end-stage renal failure. The incidence of contrast nephrop- athy varies greatly between studies (0.8 to 30%), 5,6 and appears to depend on multiple factors including pre-exist- ing renal dysfunction and hypovolemia. As such, it is routine practice to question the use of intravenous contrast in patients with high serum creatinine, especially if an alternative study is available. If no alternative is suitable and time permits, a number of measures that have been shown to reduce the risk of contrast nephropathy can be tried 7 (e.g. N-acetylcysteine  24 hours before contrast exposure). 8 However, the actual incidence of contrast nephropathy in trauma patients remains unclear, especially in the severely injured patient with a number of factors that are indepen- dently associated with the risk of developing renal insuffi- ciency (such as hypovolemia or rhabdomyolysis). 9,10 Further- more, in these patients, delays in diagnosis, adverse sequelae of missed injuries (e.g. sepsis), and nontherapeutic operations may prove to be more detrimental to the patient than the risk of contrast nephropathy. As such, the clinician is left with the dilemma, particularly when a trauma patient presents with a high serum creatinine— does the risks and benefits of pro- ceeding with iv contrast study outweigh the risks of not doing the test? To address this question the following retrospective study was undertaken. Submitted for publication October 26, 2004. Accepted for publication March 7, 2005. Copyright © 2005 by Lippincott Williams & Wilkins, Inc. From the Sunnybrook and Women’s College Health Sciences Centre (L.N.T., H.T., P.H., F.D.B., S.B.R., P.W.S., P.C.) Department of Surgery and Interdepartmental Division of Critical Care Medicine (G.S.R.), University of Toronto; Grady Memorial Hospital, Department of Surgery, Emory Univer- sity, Atlanta, Georgia. Presented at the 63rd Annual Meeting of the American Association for the Surgery of Trauma, September 29 –October 2, 2004, Maui, Hawaii. Address for reprints: L.N. Tremblay, Sunnybrook & Women’s College Health Sciences Centre, 2075 Bayview Ave., Suite H171, Toronto, Ontario, Canada M4N 3M5; email: lorraine.tremblay@sw.ca DOI: 10.1097/01.ta.0000194694.71607.0c The Journal of TRAUMA  Injury, Infection, and Critical Care 1162 November 2005