What are the risks of using radiocontrast dye in a patient with Chronic Kidney Disease (CKD) stage II and impaired renal function, specifically with a Glomerular Filtration Rate (GFR) of 55?

From the Guidelines

Patients with CKD stage II (GFR of 55 ml/min/1.73m²) have a low to moderate risk of contrast-induced acute kidney injury (CI-AKI) when receiving radiocontrast dye. While the risk is lower than in more advanced CKD stages, preventive measures are still recommended. These patients should receive adequate hydration with isotonic saline (1-1.5 ml/kg/hr) for 6-12 hours before and after the procedure, as recommended by the 2014 ESC/EACTS guidelines on myocardial revascularization 1. Consider using low or iso-osmolar contrast agents like iodixanol or iopamidol rather than high-osmolar agents, and use the minimum necessary contrast volume, as suggested by the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes 1. Temporarily discontinue potentially nephrotoxic medications such as NSAIDs, aminoglycosides, and metformin 24-48 hours before the procedure. N-acetylcysteine (600-1200 mg twice daily) may be given the day before and day of the procedure, though evidence for its benefit is mixed, as noted in the 2016 American Society of Transplantation Liver and Intestine Community of Practice recommendations 1. Monitor renal function by checking serum creatinine 24-72 hours after contrast administration. The risk of CI-AKI exists because contrast media can cause renal vasoconstriction and direct tubular toxicity, though with a GFR of 55, the absolute risk is relatively low (approximately 2-5%) compared to patients with more severe kidney disease. Some key points to consider:

• The use of iso-osmolar contrast agents, such as iodixanol, may reduce the risk of CI-AKI in patients with CKD, as shown in the RECOVER trial 1.
• The KDIGO guidelines recommend using either iso-osmolar or low-osmolar iodinated contrast media in patients at increased risk of CI-AKI, such as those with CKD 1.
• The 2009 ACCF/AHA focused update incorporated into the ACC/aha 2007 guidelines for the management of patients with unstable angina/non-ST-elevation myocardial infarction recommends the use of isosmolar contrast agents in patients with CKD undergoing angiography 1.
• The 2006 ACC/AHA practice guidelines for the management of patients with peripheral arterial disease recommend the use of alternative imaging agents, such as carbon dioxide or gadolinium, to mitigate the risk of contrast-induced acute renal failure in patients with CKD 1.

From the FDA Drug Label

1. 3 Contrast-Induced Acute Kidney Injury Acute kidney injury, including renal failure, may occur after iodixanol administration Risk factors include: pre-existing renal impairment, dehydration, diabetes mellitus, congestive heart failure, advanced vascular disease, elderly age, concomitant use of nephrotoxic or diuretic medications, multiple myeloma/paraproteinaceous diseases, repetitive and/or large doses of an iodinated contrast agent. Use the lowest necessary dose of iodixanol in patients with renal impairment Adequately hydrate patients prior to and following iodixanol administration.

The patient with Chronic Kidney Disease (CKD) stage II and a Glomerular Filtration Rate (GFR) of 55 is at risk for Contrast-Induced Acute Kidney Injury due to pre-existing renal impairment. Key considerations for this patient include:

• Using the lowest necessary dose of iodixanol
• Adequate hydration prior to and following administration
• Monitoring for signs of acute kidney injury 2

From the Research

Risks of Radiocontrast Dye in CKD Stage II Patients

The use of radiocontrast dye in patients with Chronic Kidney Disease (CKD) stage II and a Glomerular Filtration Rate (GFR) of 55 poses several risks, including:

• Contrast-induced nephropathy (CIN), a form of acute renal failure that can occur within 24-72 hours of exposure to radiocontrast media 3
• Reduction in medullary blood flow leading to hypoxia and direct tubule cell damage 3
• Formation of reactive oxygen species 3

Risk Factors for CIN

Patients with preexisting renal impairment, such as those with CKD stage II, are at higher risk for CIN 3, 4, 5. Other risk factors include:

• Diabetes mellitus 4, 6
• Angiotensin converting enzyme (ACE) inhibitor therapy 4
• Heart failure 6
• Older age 6
• Anemia 6
• Left ventricular systolic dysfunction 6

Preventive Measures

To minimize the risk of CIN, several preventive measures can be taken, including:

• Monitoring renal function by measuring serum creatinine and calculating the eGFR before and after the procedure 3
• Discontinuing potentially nephrotoxic medications 3, 5
• Choosing radiocontrast media at the lowest dosage possible 3, 5
• Encouraging oral or intravenous hydration 3, 5, 6
• Using iso-osmolar contrast media instead of high-osmolar contrast media 5, 7
• Considering the use of N-acetylcysteine or ascorbic acid in high-risk patients 5, 6

Guidelines for CKD Patients

The Canadian Association of Radiologists recommends that patients with a GFR <60 mL/min undergo preventive measures to minimize the risk of CIN 5. The use of radiocontrast agents in CKD and ESRD patients requires additional consideration, and strategies to avoid CIN may differ among this population 7.