Also Known As: Contrast-Induced Acute Kidney Injury (CI-AKI) or Contrast-Associated Acute Kidney Injury (CA-AKI)

Definition: An Increase in Cr ≥ 0.5 mg/dL or 25% Increase from Baseline within 48-72 Hours of Contrast Exposure

• May Consider Diagnosis Past 72 Hours of Contrast Exposure if No Other Cause Can Be Identified

Pathophysiology

• Direct Cytotoxic Effects in the Proximal Convoluted Tubule
• Cellular Damage from Reactive Oxygen Species
• Increased Resistance to Blood Flow in the Kidney
• Metabolites Cause Renal Vasoconstriction

Risk Factors

• GFR < 60 ml/min/1.73 m²
  • Increased Risk with Lower GFR’s
• Elderly
• Preexisting Renal Failure
• Significant Contrast Load
• Diabetes
• Hypertension
• Hypotension
• Congestive Heart Failure (CHF)
• Recent Myocardial Infarction (MI)
• Intra-Aortic Balloon Pump (IAMP)
• Anemia

Progression

• Cr Rise is Acute, Usually within 2-3 Days
  • May Still Have a Normal Urine Output (UOP)
• Peaks After 2-5 Days
• Returns to Baseline After 10-14 Days
• Permanent Damage is Rare if Baseline Function Was Normal

Prevention/Management

• Prevent by Fluid Hydration Before and After the Procedure
• IV Normal Saline at 1 ml/kg/hr for 6-12 Hours Before and Continued After
• Interventions with No Proven Benefit:
  • N-Acetylcysteine
  • Sodium Bicarbonate (Urinary Alkalinization)
  • Fenoldopam
  • Ascorbic Acid (Vitamin C)

See Also:

• *See Acute Kidney Injury (AKI)