Contrast CT Scans in the Emergency Department Do Not Increase Risk of Adverse Renal Outcomes

Michael Heller, MD; Paul Krieger, MD; Douglas Finefrock, DO; Thomas Nguyen, MD; Saadia Akhtar, MD


Western J Emerg Med. 2016;17(4):404-408. 

In This Article



It has long been accepted that intravenous contrast used in both computed tomography (CT) and plain imaging carries a risk of nephropathy and renal failure, particularly in subpopulations thought to be at highest risk.[1–3] Although early studies used high osmolality contrast media that is not typical of emergency department (ED) use today, the issue of contrast-induced nephropathy (CIN) is still an area of active interest with many studies appearing each year from many different specialties, on its pathogenesis, incidence, prevention and treatment.[4–7] The plethora of data has usually focused on the incidence of CIN, usually defined as a small (such as 25% or an absolute increase of 0.5mg/dL) increase in creatinine after receiving intravenous (IV) contrast for either a particular indication (such as cardiac catheterization) or in a particular patient group (diabetics); the meaning of a creatinine rise in this setting is not at all clear, however.[8–10] Many regimens have been proposed to ameliorate this creatinine rise, but there is a scarcity of data on what actual adverse clinical events occur and whether these can truly be ascribed to the IV contrast itself rather than the events that might well occur in a (usually) hospitalized population that required imaging. A few authors have even expressed doubt as to whether modern iodinated contrast (which is iso-osmolal) is a nephrotoxin.[11–13]

The primary objective of this retrospective, computerized chart review was to investigate an ED population of patients receiving IV contrast for CT scanning for the occurrence of two patient-oriented outcomes, death and dialysis, and compare this incidence to a contemporaneous control group of ED patients receiving similar CTs but without IV contrast. We also sought to determine if the incidence of CIN, as traditionally defined, was actually higher in the contrast group. Note that we use the traditional term "CIN" for those exhibiting a creatinine rise after CT scanning even though no patient in the control group actually received contrast.