Contrast-induced nephropathy

Acute kidney injury is a common complication after contrast administration in radiology or cardiology. It increases morbidity and in-hospital but also long-term mortality. The pathophysiology is complex, there is on association of direct cellular toxicity of contrast agents and medullary ischemia secondary to alterations in intra-renal hemodynamics and to an increase in metabolic activity. Many risk factors have been identified and should be checked prior to injection, the most important being pre-existing renal failure which might be identified by calculating the estimated glomerular filtration rate with predictive equations such as Cockcroft-Gault or MDRD equations. When risk factors are present and contrast administration is really necessary, the only validated measure to reduce the risk of renal failure is still volume expansion. Other pharmacological interventions hove interesting results, but a confirmation on a larger scale is necessary. The volume expansion is best performed intravenously by the isotonic saline or sodium bicarbonate.