Kontrastnephropati

Kontrastnephropati, also known as contrast-induced nephropathy (CIN), is a form of acute kidney injury that occurs after the administration of iodinated contrast media during radiologic imaging procedures such as computed tomography or angiography. It is typically defined as an increase in serum creatinine by at least 0.5 mg/dL (44 μmol/L) or by 25 percent from baseline within 48 to 72 hours after exposure, in the absence of another cause.

The pathophysiology is multifactorial and not fully understood. It involves renal vasoconstriction and medullary hypoxia, direct tubular toxicity from the contrast agent, and generation of reactive oxygen species and inflammatory mediators. Higher contrast dose, higher osmolality, and preexisting kidney impairment increase susceptibility.

Risk factors include chronic kidney disease, diabetes mellitus, advanced age, dehydration, congestive heart failure, nephrotoxic medications, and planned use of large volumes or high-osmolality contrast media. Repeated contrast exposure within a short interval also increases risk.

Prevention focuses on risk stratification and hydration. Strategies include adequate isotonic fluid hydration before and after imaging, using the lowest feasible contrast dose and preferring iso-osmolar or low-osmolar agents, and avoiding nephrotoxic drugs when possible. The role of sodium bicarbonate infusion and N-acetylcysteine is uncertain, with mixed evidence.

Diagnosis relies on laboratory monitoring of kidney function after exposure, typically baseline creatinine and repeat measurements at 48 to 72 hours. Management is supportive, including monitoring and treating complications; most cases resolve with recovery of renal function, but severe cases can lead to persistent kidney injury or require temporary dialysis, especially in high-risk patients.