What may occur as a side effect of high osmolality contrast media?

High osmolality contrast media can lead to various physiological responses when introduced into the body. One notable side effect is the sensation of warmth, redness, and flushing, particularly in vascularized areas where the contrast is injected. This occurs due to the rapid influx of the contrast agent into the blood vessels, leading to vasodilation and increased blood flow, which can manifest as localized redness and a warming sensation.

While severe allergic reactions can occur, they are more commonly associated with iodine-based contrast materials and vary in presentation. Increased fluid retention is less specifically tied to high osmolality contrast media; while it may occur under certain conditions, it is not a primary response associated with these agents. Therefore, flushing and redness are the most characteristic side effects that occur directly after administration of high osmolality contrast media.