Determination of serum creatinine level before intravenous administration of iodinated contrast medium. A survey.

RATIONALE AND OBJECTIVES

To study the practice of obtaining serum creatinine before administering intravenous iodinated contrast medium and the costs associated with this practice.

MATERIALS AND METHODS

In June 1993, a questionnaire was sent to 217 physicians who are members of the Society of Uroradiology or the Society of Computed Body Tomography/Magnetic Resonance. There were 149 respondents who completed a total of 70 questionnaires, providing a response rate of 69% (149/217).

RESULTS

The percentage of institutions that always require a serum creatinine before administering intravenous contrast medium for excretory urography, body computed tomography, and head computed tomography was 13%, 20%, and 14%, respectively. In institutions where routine serum creatinine is not required, approximately 60% request a serum creatinine in either insulin-dependent or juvenile type 1 diabetes. The mean maximal acceptable time between the serum creatinine value and contrast administration is 29 days. It takes a mean of 69 minutes to get the results of a stat serum creatinine and costs a mean of 15 dollars for the test. In patients with no risk factors, the mean for the highest serum creatinine value at which respondents still gave contrast was 2.1 mg/dL; in patients with risk factors, the mean was 1.9 mg/dL. There was no correlation between the use of serum creatinine and the number of studies performed in the institution or the type of contrast used.

CONCLUSIONS

The practice of requiring a pretest serum creatinine and its interpretation regarding the use of contrast media are quite variable. In view of this disparity in opinion, development and acceptance of a list of patients who are at increased risk for contrast-induced nephropathy may be desirable.