Is measurement of renal function necessary for all trauma patients before iodinated contrast administration?

The purpose of this study was to identify factors at the time of presentation which could quickly exclude or identify renal dysfunction in blunt trauma patients, thus negating serum measurement of renal function prior to contrast-enhanced imaging and expediting care.

Patients, >18 years old, without renal failure, presenting after blunt trauma, with serum creatinine measured at presentation, were retrospectively studied at a single center. Variables recorded at presentation including vitals, mechanism, and past medical history were analyzed using multivariate regression analysis to identify independent predictors of abnormal renal function.

From 2009 to 2015, a total of 1099 patients met the inclusion criteria. Of those, 75 (6.8%) had renal dysfunction at presentation. Patients with renal dysfunction had a mean age of 74.3 (SD 15.5) years old, and 57.3% were male. Multivariate analysis identified independent predictors of renal dysfunction at presentation as age ≥ 61 (p < 0.001), hypotension (p = 0.02), and diabetes (p = 0.02). The presence of a single identified factor had an 85% sensitivity for renal dysfunction and a 98.5% negative predictive value.

Impaired renal function at presentation was infrequent in our trauma cohort. Trauma patients who were normotensive, under the age of 61, and without diabetes were unlikely to have impaired renal function at presentation. In the urgent setting of trauma, patients without these comorbidities are likely safe to forgo screening of renal function prior to contrast-enhanced imaging.