What is the management of Contrast-Induced Nephropathy (CIN), also known as Impaired Renal Function, following the administration of contrast media (intravenous iodine or gadolinium-based agents)?

From the Guidelines

The management of contrast-induced nephropathy (CIN) should prioritize prevention through adequate hydration with intravenous isotonic saline, minimizing contrast volume, and using iso-osmolar or low-osmolar contrast agents in high-risk patients. According to the 2014 ESC/EACTS guidelines on myocardial revascularization 1, patients undergoing coronary angiography or MDCT should be assessed for risk of contrast-induced AKI, and those with moderate-to-severe CKD should receive hydration with isotonic saline. The guidelines recommend using low-osmolar or iso-osmolar contrast media, with a volume of contrast media minimized, especially in patients with eGFR <40 mL/min/1.73 m².

Key measures to prevent CIN include:

• Hydration with isotonic saline (1-1.5 mL/kg/hour for 6-12 hours before and 4-12 hours after contrast exposure) 1
• Minimizing contrast volume, using the lowest dose necessary for adequate imaging 1
• Using iso-osmolar or low-osmolar contrast agents in high-risk patients (eGFR <30 mL/min/1.73m²) 1
• Temporarily discontinuing nephrotoxic medications such as NSAIDs, aminoglycosides, and ACE inhibitors 24-48 hours before contrast administration
• Monitoring renal function 48-72 hours post-procedure in high-risk patients

It is also important to note that N-acetylcysteine administration instead of standard hydration is not indicated 1, and infusion of sodium bicarbonate 0.84% instead of standard hydration is not recommended 1. Prophylactic renal replacement therapy is also not recommended as a preventive measure 1.

In patients with severe CKD, fluid replacement rate should be 1000 mL/h without negative loss, and saline hydration should be continued for 24 hours after the procedure 1. Overall, these measures are crucial in preventing CIN, which can lead to acute kidney injury, particularly in patients with pre-existing renal impairment, diabetes, or dehydration.

From the Research

Management of Contrast Induced Nephropathy

• The management of contrast induced nephropathy (CIN) involves various preventive measures, as CIN is the third most common cause of acute kidney injury and is associated with an unfavorable prognosis 2, 3.
• The cornerstone of CIN prevention is adequate parenteral volume repletion, and pericatheterization hydration is almost universally accepted as an appropriate and safe measure to prevent CIN 2, 3.
• Discontinuation of potentially nephrotoxic drugs 2-3 days before and after the procedure, and using the lowest possible dose of contrast medium can also decrease the risk of CIN 2, 3.
• Other prophylactic strategies, such as the use of low or iso-osomolar contrast agents, and minimizing contrast volume, can also be effective in preventing CIN 3, 4.
• The use of certain medications, such as N-acetylcysteine, sodium bicarbonate, statins, and ascorbic acid, has been studied for reducing CIN, with some showing clinically important and statistically significant benefits 5.
• Identification of patients at risk and implementation of preventive strategies can decrease the incidence of CIN, and knowledge of the adverse effects associated with infusion of contrast media is crucial in preventing CIN 6.

Prevention Strategies

• Preprocedural hydration with isotonic solution is the standard of care for prophylaxis 4.
• The use of N-acetylcysteine plus IV saline has been shown to have a clinically important and statistically significant benefit in reducing CIN 5.
• Statins plus N-acetylcysteine plus IV saline has also been shown to have a clinically important and statistically significant benefit in reducing CIN 5.
• Sodium bicarbonate, statins, and ascorbic acid have also been studied for reducing CIN, although the evidence is generally insufficient for comparisons of the need for renal replacement, cardiac events, and mortality 5.

Risk Factors

• Chronic kidney disease is the primary predisposing factor for CIN 3.
• Modifiable risk factors for CIN include hydration status, the type and amount of contrast, use of concomitant nephrotoxic agents, and recent contrast administration 3.
• Patients with estimated glomerular filtration rate <60 ml/1.73 m2 are at high risk for CIN 3.