Time to Inject Some Contrast into the Nephrotoxicity Debate.

Iodinated contrast media have long been feared for causing "contrast-induced AKI" (CI-AKI), a concern rooted in early reports with high-osmolar agents. Experimental data suggest potential nephrotoxic mechanisms, yet clinical evidence from older uncontrolled studies was confounded by comorbidities and procedural risks. Contemporary propensity-matched and controlled analyses consistently show that modern low- and iso-osmolar contrast agents (mostly intravenously administered) uncommonly cause true nephrotoxicity, even among high-risk populations such as patients with advanced chronic kidney disease, acute kidney injury, or critical illness. Large randomized trials, including PRESERVE, found no difference in outcomes between sodium bicarbonate and isotonic saline hydration as preventive strategies, nor N-acetylcysteine administration, and highlighted risks like fluid overload. Persistent fear of CI-AKI has fueled "renalism": unnecessary avoidance or delay of essential imaging, leading to worse outcomes. Current consensus emphasizes individualized care-avoiding hypovolemia, limiting contrast dose, and withholding nephrotoxins only in severe kidney impairment. A balanced, evidence-based approach should replace outdated caution.