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Contrast-Induced Nephropathy (CIN)

Presentation

• Radiocontrast Induced Renal Failure:
  • Usually mild, transient, and nonoliguric.
  • Begins within 12-24 hours of contrast administration.
  • Recovery typically within 3-5 days.
• Severe Cases:
  • Creatinine peaks > 5 mg/dL (440 μmol/L), particularly if baseline plasma creatinine > 4 mg/dL (352 μmol/L).
  • May require dialysis.
  • Persistent renal failure occurs in patients with advanced underlying disease, especially diabetics.

Diagnosis

• Characteristic Rise in Plasma Creatinine:
  • Begins within the first 12-24 hours post-contrast administration.
• Differential Diagnosis:
  • Consider ischemic acute tubular necrosis, acute interstitial nephritis, and renal atheroemboli.
  • Renal Atheroemboli Indicators:
    • Presence of embolic lesions or livedo reticularis.
    • Transient eosinophilia and hypocomplementaemia.
    • Delayed onset renal failure (days to weeks post-procedure).
    • Protracted course with minimal or no recovery of renal function.

Risk Factors

View or edit this diagram in Whimsical.

Prevention of Contrast-Induced Nephropathy

View or edit this diagram in Whimsical.

Management of Contrast-Induced Acute Renal Failure

• General Management:
  • No specific treatment for contrast-induced acute renal failure.
  • Manage as acute tubular necrosis, focusing on fluid maintenance and electrolyte balance.

Summary of Strategies

• Optimal Prophylaxis:
  • Uncertain but includes avoidance of volume depletion and NSAIDs.
• At-Risk Patients (Defined by Rudnick et al):
  • Plasma creatinine > 1.5 mg/dL (132 mmol/L) or eGFR < 60 mL/1.73 m², especially in diabetics.
  • Recommendations:
    • Use non-contrast diagnostic modalities where possible.
    • Avoid high osmolal agents (Grade 1A).
    • Prefer iso-osmolal agents to low osmolal agents (Grade 2B).
    • Use lower doses of contrast and avoid repetitive studies < 48 hours apart.
    • Administer isotonic IV fluids before and after contrast administration (Grade 1B).

Fluid Regimen for Prophylaxis

• Isotonic Saline:
  • 1 mL/kg/hr, started at least 2 and preferably 6-12 hours prior to the procedure, and continued for 6-12 hours after contrast administration.
• Isotonic Bicarbonate:
  • Bolus of 3 mL/kg over 1 hour pre-procedure, continued at 1 mL/kg/hr for 6 hours post-procedure.
  • Preparation: Add 150 meq sodium bicarbonate to 850 mL of 5% dextrose in water.

Reduction of Incidence After a Previous Reaction

1. Stop β-Blockers.
2. Premedicate with Corticosteroids ± Antihistamines.
3. Consider Alternative Contrast Mediums:
   • CO₂ or CO₂ DSA.

Links

• Renal Physiology
• Renal transplant
• Renal protection
• Intra-op renal dysfunction
• ICU and renal disease

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Past Exam Questions

Prevention of Contrast-Induced Nephropathy and Contrast Reactions

A 55-year-old patient with ischaemic heart disease is booked for coronary angiography. He is diabetic and hypertensive.
a) How will you minimise the risk of contrast-induced nephropathy in this patient? (7)
b) This patient has had a previous angiography study and reacted to the contrast medium used, and a repeat angiography has to be performed. How will you reduce the incidence of the reaction? (3)

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References:

1. Papendorf, D. (2007). Radiocontrast nephropathy: (renal protection). Southern African Journal of Anaesthesia and Analgesia, 13(6), 26–31. https://doi.org/10.1080/22201173.2007.10872509

Summaries:

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© 2025 Francois Uys. All Rights Reserved.

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