ABSTRACT

Although contrast-induced nephropathy (CIN) is a well-known cause of acute renal failure, the development of CIN remains poorly understood. Several studies have been performed with the aim of shedding some light onto the pathophysiology of CIN. However, these studies have yielded various interpretations with sometimes contradictory conclusions. Although it is but one of several physicochemic properties of contrast media (CM), osmolality has received considerable attention. Osmolality serves to assign CM to different classes. Some of the recently developed iso-osmolar CM are dimers, not monomers as are the widely used, non-ionic, low-osmolar CM. However in spite of being iso-osmolar, they have physicochemic features which differ from other CM, for example in terms of viscosity, which is >5-fold greater than plasma viscosity. This fact may be of considerable pathophysiologic and clinical importance. Several experimental studies provide evidence that iso-osmolar CM produce a greater perturbation in renal function in comparison to non-ionic, low-osmolar CM.