Lecture 4: Contrast complications

Question 1

why use contrast medium

Answer 1

1. Opacify specific structures to increase contrast resolution
2. With radiography only way to differentiate structures is when they are different opacities

Question 2

what are the 4 types of contrast

Answer 2

1. Gas
2. Barium
3. Iodinated
4. Paramagnetic agents

Question 3

what are the routes of administering contrast

Answer 3

IV, intrathecal, intraperitoneal, oral, intra-articular

Question 4

Is hypague 76 contrast ionic or non-ionic

Answer 4

ionic

Question 5

are iohexol 350 and 240 ionic or non-ionic contrasts

Answer 5

non-ionic

Question 6

what are some indications for iodinated contrast

Answer 6

urinary study, angiography, CT, lymph angiography, arthrography, myelography

Question 7

Only use ionic or non-ionic iodinated contrast in myelographs

Answer 7

non-ionic

Question 8

Iodinated contrast is __times the osmolality of plasma

Answer 8

5-8 times

Question 9

what is the advantage of ionic contrast

Answer 9

less expensive

Question 10

what are the disadvantages of ionic contrast

Answer 10

hypertonicity- increased risk of reaction

Question 11

You can not administer ionic contrast __

Answer 11

intrathecally

Question 12

what are some advantages of non-ionic contrast

Answer 12

lower reaction rate, less hypertonic, useful for any procedure

Question 13

what is the disadvantage for non-ionic contrast

Answer 13

expensive

Question 14

what are some toxicities associated with iodinated contrast

Answer 14

1. Osmolality- primary effect
2. Ionic charge
3. Chemical toxicity
4. Allergic or idiosyncratic reaction

Question 15

the osmolality/ hypertonicity of iodinated contrast causes a shift of water from ___ to ___ space, and a shift of water out of ___

Answer 15

extravascular to intravascular, RBC

Question 16

what endothelial and RBC lesions are seen as the result of negative osmolality effects

Answer 16

1. Desiccation and weakening of junctions
2. Increase capillary permeability
3. RBC dedicate and are rigid
4. Risk of thrombosis formation

Question 17

what are the cardiovascular effects of osmolality changes from iodinated contrast

Answer 17

1. Vasodilation- severe hypotension
2. Osmotic hypervolemia
3. Reflex bradycardia

Question 18

what are the renal affects of osmolality changes from iodinated contrast

Answer 18

diuresis, acute renal failure- hypertonicity and chemical toxicity

Question 19

what are some non-specific reactions to osmolality changes from iodinated contrast

Answer 19

nausea, vomiting, chills, fever, headache

Question 20

CNS is very sensitive to ionic composition changes and can result in __ or ___

Answer 20

seizures or cardiac dysfunction

Question 21

ionic or non-ionic: results in ionic composition changes that can cause seizures or cardiac dysfunction

Answer 21

ionic (does not occur with non-ionic)

Question 22

T or f: sodium is toxic but compounds with megluimine are less toxic

Answer 22

true

Question 23

t or f: non-ionic compounds have no sodium, therefore less toxic

Answer 23

true

Question 24

Iodinated compounds directly induce ___degranulation and ___release

Answer 24

mast cell, histamine

Question 25

T or F: iodinated contrasts suppress erythrocyte function

Answer 25

true

Question 26

which intrathecal iodine injection site has increased adverse reactions: cisternal or lumbar

Answer 26

cisternal>lumbr

Question 27

how do you determine volume of contrast given intrathecal

Answer 27

volume of contrast/mL of CSF

Question 28

what factors have no effect on incidence of reactions in intrathecal iodine administration

Answer 28

dose, time of anesthesia, anesthetic protocol

Question 29

__therapy may decrease risk of seizures when administering intrathecal iodine

Answer 29

fluid

Question 30

what neurotoxicities are associated with iodinated contrast administration

Answer 30

1. increased capillary permeability in BBB allows toxic substances to contact neurons 2. Ionization disrupts neurotransmission

Question 31

what are some intrathecal iodine reactions

Answer 31

1. Seizures 2. Hyperthermia 3. Transient apnea 4. Transient muscle spasms 5. Hypotension 6. Opisthotonus

Question 32

what is gadolinium based contrast

Answer 32

injectable paramagnetic substance

Question 33

paramagnetic substances shorten __ and __relxation times

Answer 33

T1 and T2

Question 34

T or F: gadolinium is highly toxic

Answer 34

true

Question 35

since gadolinium is highly toxic is must be ___

Answer 35

chelated, DTPA most common

Question 36

what are the mechanism of reactions associated with gadolinium based contrast

Answer 36

stability, osmolality

Question 37

what are some indications for gas contrast

Answer 37

cystography, pneumoventriculography, ultrasound, peritoneography, pericardiography

Question 38

what are some reactions associated with gas contrast

Answer 38

air emboli- rare complication

Question 39

what are some signs of air emboli from gas contrast

Answer 39

occlude flow, infarct of affected area

Question 40

what is tx for air emboli from gas contrast

Answer 40

Place left lateral recumbency and catheterize right atrium to try and extract emboli (often fatal complication)

Question 41

What reactions are associated with barium contrast

Answer 41

only concern if extravasation into body cavity- severe granulomatous inflammation

Question 42

what are some signs of a barium reaction

Answer 42

abdominal pain, mild to severe peritoneal adhesions

Question 43

what is tx for barium reaction

Answer 43

immediate lavaging may minimize reaction