Clinical question: Does the use of contrast media in CT scans cause acute kidney injury (AKI)?

The bottom line:

• The use of contrast enhanced CTs is imperative in making timely diagnosis in critical illness.

• For years, it has been thought that contrast media leads to AKI.

• Previous studies are limited with many based on the use of hyper-osmolar and large volumes of contrast.

• Moreover, older studies drew conclusions without comparing to a control group.

• Newer, controlled, observational studies have shown no associated between contrast media and the development of AKI.

Study 1: Hinson 2017

• Single-center retrospective cohort analysis of 17,934 patients who underwent contrast enhanced (CECT), non-contrast enhanced, or no CT. 
• Objective: evaluate the incidence of AKI attributable to IV contrast

Propensity Score Matching:

Limitations: retrospective, observational, single center study design. Most patients were admitted so potentially were at higher risk for developing AKI, thus over-reporting the incidence of AKI. No randomization to account for all factors that may influence the clinical decision to administer contrast. 

Study 2: Hinson 2019

• Single-center retrospective propensity matched cohort analysis of 4171 patients who underwent CECT, non-contrast enhanced, or no CT in the ED. 
• Objective: Determine the risk for AKI attributable to IV contrast in patients with sepsis.

Limitations:  single center, retrospective study design. May have potentially missed cases of AKI who were discharged earlier than the majority of participants who were hospitalized for 2+ days. Providers may have avoided CECT in those with lower baseline sCr and GFR.  Baseline characteristics between groups were not equal, specifically initial sCr as well as history of CHF and diabetes. Significant number of patients (35%) were eliminated secondary to delay in obtaining initial sCr level.

References:

Hinson JS et al. Risk of Acute Kidney Injury After Intravenous contrast Media Administration. Ann Emerg Med 2017; S0196 – 0644(16): 31388 -9. PMID: 28131489

Hinson JS et al. Acute Kidney Injury Following contrast Media Administration in the Septic Patient: A Retrospective Propensity-Matched Analysis. J Crit Care 2019. PMID: 30798098