Acvr - Special Procedures - General

Front 1

What is the "Z" of Barium?

Back 1

56

Front 2

How would you prepare a 20% weight-to-volume suspension?

Back 2

Add 20g of Barium to enough water to total 100mL

(or add 40g of barium to enough water to total 200mL)

Front 3

How would you prepare a 20% weight-to-weight solution?

Back 3

Add 20g Barium to 80g (80mL) water to total 100g

(or add 40g of barium to 160g (160mL) of water to total 200g)

Front 4

If asked to prepare a 100% weight-to-weight solution, what would you hand them?

Back 4

dry barium sulfate powder

Front 5

What is another term for a percutaneous cannulation needle and how is it designed?

Back 5

Seldinger needle

beveled tip with two cutting edges

Front 6

What is the purpose for Teflon-coated, heparin-treated guide-wires?

Back 6

reduced thrombogenicity

Front 7

The stiffer the catheter the ________ friction it will generate.

Back 7

less

Front 8

The excellent tensile properties of polyurethane make it an excellent compound for which type of catheter?

Back 8

pigtail

Front 9

List some of the limitations/risks of end-hole catheter usage.

Back 9

1. More likely to recoil

2. Induce arrhythmias

3. Extend beyond your target region accidentally

Front 10

Pigtail catheters have side-holes and end-holes. What is the disadvantage of this type of catheter?

Back 10

thrombogenic

(difficult to flush)

Front 11

Name the catheter that has an end-hole and is used for blood sampling and pressure recording.

Back 11

Lehman

Front 12

Name the catheter that has a balloon-end-hole and is often used to obtain pulmonary arterial wedge pressures.

Back 12

Swan-Ganz

Front 13

What is the consequence of Barium aspiration and what is its clinical importance?

Back 13

benign granulomas

(not too bad)

Front 14

When is Barium administration contraindicated?

Back 14

Perforation of esophagus or GI tract

(50% mortality)

Front 15

Above all else, the adverse effects of administration of ionic contrast agents are attributed to what?

Back 15

hypertonicity

Front 16

List the benefits of non-ionic agents.

Back 16

1. lower osmolality (closer to plasma)

2. do not dissociate in solution

3. no ions, no Na+

4. 6x safer

Front 17

Which of the following is an ionic contrast agent?

a. iopamidol

b. iotrolan

c. metrizamide

d. iodixanol

Back 17

none of the above

(HINT: hate the __ate)

Front 18

Name the neurotoxic non-ionic agent that is contraindicated for myelography.

Back 18

metrizamide

(seizures during recovery)

Front 19

What are the only two disadvantages to non-ionic contrast media?

Back 19

1. high cost

2. increased viscosity

Front 20

Which ionic agent has a relatively lower osmolality?

Back 20

ioxaglate

Front 21

Side effects of ionic contrast agents are directly proportional to their degree of what?

Back 21

hypertonicity

Front 22

Although both ionic and non-ionic contrast agents have anti-coagulant properties, which is greater?

Back 22

ionic

Front 23

When can clinical signs of reaction to hypertonicity become apparent?

Back 23

5-10 minutes

Front 24

Toxicity of iodinated contrast agents is ________ proportional to protein/enzyme binding, and ________ proportional to the hydrophilia of the agent.

Back 24

directly

inversely

(remember that ionic agents are hydrophilic due to their charge and non-ionic agents are hydrophilic due to their hydroxyl groups)

Front 25

What category of adverse reaction is non-dose-dependent and elicits an allergic (not anaphylactic) response?

Back 25

idiosyncratic

Front 26

Which 3 organs are most sensitive to hypertonicity?

Back 26

1. Brain

2. Heart

3. Kidney

Front 27

List several clinical signs of hypertonicity.

Back 27

1. acute renal failure

2. increased cap. membrane / BBB permeability

3. bradycardia

4. CHF (osmotic hypervolemia)

Front 28

True or False:

Hypertonic contrast media is more commonly associated with non-idiosyncratic reactions.

Back 28

True

(dose-dependent)

Front 29

What inherent chemical structural component renders non-ionic agents safer?

Back 29

They contain hydroxyl groups (OH)

OH groups imply hydrophilicity

(iohexol has 6 OH groups)

Front 30

How does the viscosity of an agent correspond with its potential neurotoxicity?

Back 30

higher viscosity = higher contact time

(and thus greater potential toxic effects)

Front 31

What is the advised concentration of iohexol during myelographic procedures?

Back 31

200-240 mg/mL

Front 32

The LD50 of iopamidol = 1490.

The LD50 of iohexol = 840.

Which agent is technically safer?

Back 32

iopamidol

Front 33

In what time frame after administration of the contrast agent is neurotoxicity seen?

Also, list two clinical signs of neurotoxicity.

Back 33

2-12 hours

nausea and seizures

Front 34

In cases of contrast medium induced nephrotoxicity, when do creatinine elevations peak?

When does the azotemia spontaneously resolve?

Back 34

3-4 days

1-2 weeks

Front 35

List 3 risk factors for potential development of nephrotoxicity.

Back 35

1. elevated creatinine

2. dehydration

3. hypertension

Front 36

What is the primary treatment for subsequent nephrotoxicity?

Back 36

diuresis and dopamine

Front 37

What is the pathophysiologic explanation for contrast-induced nephrotoxicity?

Back 37

1. It reduces water reabsorption in the proximal tubules.

2. Increased hydrostatic pressure causes

increased GFR resistance.

3. It increases urine viscosity resulting in increased tubular hydrostatic pressure and thus decreased GFR.

Front 38

What is the major complication associated with thoracic FNAs and what is its prevalence?

Back 38

Pneumothorax

(17%)

Front 39

In cases of large heartworm burden, where are the worms commonly found?

Back 39

vena cava and right ventricle

Front 40

In cases of infection with fewer heartworms, where may these be typically found?

Back 40

the distal pulmonary arteries

Front 41

True or False?

The approximate number of female heartworms present correlates well with heartworm-antigen concentration.

Back 41

True

Front 42

Outline the normal fluoroscopic sequence from fluoroscopic x-ray tube to the output phosphor.

Back 42

1. X-ray photons leave the tube and go thru the patient.

2. X-rays then enter the image intensifier tube where they are converted to visible light photons.

3. These light photons strike the photocathode which then emits photoelectrons.

4. These photoelectrons accelerate across the tube toward the anode to strike the output fluorescent screen yielding....

5. Fluorescence.

Front 43

With regard to iodinated contrast media, how does the ratio of iodine atoms-to-particles in solution impact osmol-toxicity?

Back 43

The higher the ratio, the lower the toxicity

(therefore, choose non-ionic dimers over non-ionic monomers and especially over ionic monomers)

Front 44

True or False:

The fewer the number of particles in solution, the fewer the number of carboxyl groups (COH), the greater the hydroxyl groups (OH), and the safer it will be.

Back 44

True.

Front 45

What characteristic of ionic media can have bad effects upon the cardiovascular system?

Back 45

They bind calcium

(albeit weakly, but they do)

Front 46

Which non-ionic iodinated contrast agent has the relatively highest potential nephrotoxic effects?

Back 46

iohexol

Front 47

What is the primary determinant of the toxicity of solutions?

Back 47

osmolality