Which laboratory assessment is essential before iodinated contrast administration?

• A. Kidney function (serum creatinine/eGFR)
• B. Liver enzymes
• C. Coagulation profile
• D. Serum potassium

Answer: (A)

Assessing kidney function with serum creatinine and estimated GFR is essential before iodinated contrast because these agents can cause nephrotoxicity, especially in patients with existing kidney impairment. Knowing the GFR helps identify those at higher risk of contrast-induced kidney injury and guides precautions—such as using the lowest effective contrast dose, choosing safer contrast formulations, ensuring adequate hydration, and considering alternative imaging if risk is high. In patients with normal kidney function, risk is lower but still monitored.

Liver enzymes, coagulation profile, and serum potassium do not routinely determine risk for contrast-induced nephropathy. They may be relevant in other clinical contexts or procedures, but they are not the primary factors used to decide on iodinated contrast administration.