Lecture 4: Contrast complications Flashcards
why use contrast medium
- Opacify specific structures to increase contrast resolution
- With radiography only way to differentiate structures is when they are different opacities
what are the 4 types of contrast
- Gas
- Barium
- Iodinated
- Paramagnetic agents
what are the routes of administering contrast
IV, intrathecal, intraperitoneal, oral, intra-articular
Is hypague 76 contrast ionic or non-ionic
ionic
are iohexol 350 and 240 ionic or non-ionic contrasts
non-ionic
what are some indications for iodinated contrast
urinary study, angiography, CT, lymph angiography, arthrography, myelography
Only use ionic or non-ionic iodinated contrast in myelographs
non-ionic
Iodinated contrast is __times the osmolality of plasma
5-8 times
what is the advantage of ionic contrast
less expensive
what are the disadvantages of ionic contrast
hypertonicity- increased risk of reaction
You can not administer ionic contrast __
intrathecally
what are some advantages of non-ionic contrast
lower reaction rate, less hypertonic, useful for any procedure
what is the disadvantage for non-ionic contrast
expensive
what are some toxicities associated with iodinated contrast
- Osmolality- primary effect
- Ionic charge
- Chemical toxicity
- Allergic or idiosyncratic reaction
the osmolality/ hypertonicity of iodinated contrast causes a shift of water from ___ to ___ space, and a shift of water out of ___
extravascular to intravascular, RBC
what endothelial and RBC lesions are seen as the result of negative osmolality effects
- Desiccation and weakening of junctions
- Increase capillary permeability
- RBC dedicate and are rigid
- Risk of thrombosis formation
what are the cardiovascular effects of osmolality changes from iodinated contrast
- Vasodilation- severe hypotension
- Osmotic hypervolemia
- Reflex bradycardia