Editing Reduction of Risk Potential (section)

=== Iodinated Contrast Studies ===

Includes computed tomography with contrast, intravenous pyelography, angiography, and cardiac catheterization. Screen for prior contrast reaction, asthma, and renal impairment. The historical practice of screening for shellfish allergy is not supported by evidence, since the reaction is to the contrast agent rather than to iodine content in seafood; a prior reaction to contrast itself is the meaningful risk factor (American College of Radiology [ACR], 2023). Assess creatinine and estimated glomerular filtration rate. Warn the client that a warm flushing sensation and a metallic taste are expected during injection. Afterward, encourage generous oral or intravenous fluids to promote contrast excretion, and monitor urine output and renal function. '''Metformin''' is generally withheld at the time of contrast administration and for approximately 48 hours afterward in clients with impaired or at-risk renal function, with renal function reassessed before restarting, because of the risk of lactic acidosis if contrast-associated kidney injury occurs; follow facility protocol (ACR, 2023).