Question

Identify the basic difference between ionic and nonionic contrast media. Why is nonionic contrast a better choice for patient safety

Answer 1

Basic difference between ionic and non ionic contrast media is osmalarity. Ionic contrast media molecules dissociate in the solution and express more numbers of ions so have more osmalarity as compare to non-ionic contrast media. That means Non ionic contrast media is low osmolar. Second basic difference we can say the cost. Non-ionic contrast media is expensive as comoare to ionic contrast media.

Low osmolar non-ionic contrast media is better choice because it does not affect the hemodynamics as the ionic contrast media affects. Capillary/vascular endothelial cells, blood cells and any other cells which are surrounded by plasma or ECF(Extra celluar fluid) mixed with Hyperosmalar ionic contrast media experience a hypertonicity outside the cells. So the cell water comes out osmatically and cells gets shrunken. As well as osmotic hypervolumia occurs. This shrunken of vascular endothelial cells and effect of the ionic contrast media locally result in increased permeability of capillary and vasodilation respectively. These two changes result in tissue edema and low blood pressure. However non-ionic contrast media also have some osmalarity but it is far less hemodynamic changes as compare to ionic contrast media, so safe for the patients.