Classification Based on Solubility

Osmolality

concentration of dissolved particles in a solution, higher osmolality induces greater osmotic pressure, leading to fluid movement

Osmotic Pressure

force causing water to move from low osmolality body fluid to high osmolality contrast medium, leading to dehydration and increased CM reactions

Contrast Media Osmolality

higher osmolality CM increases reaction risk, lower osmolality CM reduces reaction risk

Solubility

measure of how much one substance dissolves in a solvent

Water Insoluble Contrast Media

Barium Sulfate (BaSO4)

Barium Sulfate (BaSO4)

powder or semi-solid colloidal suspension, taken orally or rectally, not soluble in water, not easily absorbed or excreted, used in GIT exams

Barium Swallow

examination of the esophagus

Barium Meal

examination of the stomach

Small Intestine Series

examination of the small intestine

Barium Enema

examination of the large intestine

Barium Sulfate Contraindications

suspected perforation or obstruction, leakage into the peritoneal cavity may cause Barium Peritonitis, which can be fatal

Post-GI/BE Examination Care

expect light-colored stools, drink plenty of fluids, increase fiber intake

Organic Iodine

liquid contrast medium, soluble in water, quickly absorbed and excreted by kidneys, fast clearance time, used in urinary, biliary, CNS, CVS, and some GIT exams Organic Iodine Usage

High Osmolar Contrast Media (HOCM)

older, less expensive, high osmolality (5-8x body fluid), higher chance of CM reactions, ionic (breaks into anion and cation)

HOCM Examples

UROGRAFIN, CONRAY

Low Osmolar Contrast Media (LOCM)

more expensive, more advanced, lower osmolality, reduced CM reaction risk

Ionic LOCM

breaks down in solution into fewer particles

Non-Ionic LOCM

does not break down into particles

Ionic LOCM Example

HEXABRIX

Non-Ionic LOCM Examples

IOPAMIRON, VISIPAQUE, OMNIPAQUE, OPTIRAY