Before performing imaging studies with IV contrast due to a positive D-Dimer, which lab value must be assessed?

Before performing imaging studies with intravenous (IV) contrast, it is crucial to assess the patient's creatinine level. This is because IV contrast agents can potentially cause contrast-induced nephropathy, especially in patients with pre-existing renal impairment. Elevated creatinine levels indicate compromised kidney function, which increases the risk of adverse effects when administering contrast media.

Monitoring kidney function, primarily through creatinine levels, helps determine whether it is safe to proceed with imaging studies that involve IV contrast. If creatinine levels are significantly elevated, alternative imaging modalities that do not require contrast (such as non-contrast CT scans or MRI) may be considered to prevent renal complications.

The other lab values listed are not directly related to the safe administration of IV contrast. Sodium, calcium, and chloride levels are important for various physiological functions and can be indicative of different medical conditions, but they do not have the same direct correlation to the risk of nephropathy from IV contrast as creatinine does. Therefore, assessing creatinine is the key step in the decision-making process for contrast-enhanced imaging.