The Association Between Radiocontrast Media and Acute Kidney Injury: A Review of the Evidence on Contrast-Induced Nephropathy

Abstract

Introduction: Iodinated radiocontrast media are indispensable for many modern diagnostic and interventional procedures. However, their use is associated with a significant risk of iatrogenic acute kidney injury (AKI), known as contrast-induced nephropathy (CIN), which is a leading cause of hospital-acquired renal failure.

Literature Review: A review of the pivotal literature establishes CIN as a major clinical concern, particularly in patients with pre-existing chronic kidney disease (CKD), the single most important risk factor. The pathogenesis is understood to be multifactorial, involving direct tubular epithelial cell toxicity and profound intrarenal vasoconstriction leading to medullary ischemia. A large body of evidence confirmed that the most effective and foundational strategy for prevention is periprocedural intravenous volume expansion with isotonic saline. The role of adjunctive pharmacological therapies was a subject of intense investigation and controversy. An influential randomized trial suggested a powerful protective effect of sodium bicarbonate infusions over saline, sparking widespread debate. Similarly, the antioxidant N-acetylcysteine was widely used based on initial promising results, but subsequent, larger trials yielded conflicting and often negative findings, leaving its role uncertain.

Conclusion: The body of evidence reviewed cemented risk stratification and adequate intravenous hydration as the undisputed cornerstones of CIN prevention. While the potential benefits of adjunctive agents like sodium bicarbonate and N-acetylcysteine were vigorously debated, their efficacy remained controversial and unproven, highlighting the complexity of this iatrogenic condition and shaping the standard of care around risk factor modification and prevention.