Chp. 4: Safety Considerations for Laser and Radiographic Procedures and MRI

Question 1

What body parts are at highest risk when using lasers?

Answer 1

Skin and eyes

Question 2

LASER

Answer 2

Light Amplification by Stimulated Emission of Radiation

Question 3

True or False: Reflected laser beams are unaltered and contain the same energy as the direct beam.

Answer 3

True.

Question 4

What laser classes are most common in veterinary medicine?

Answer 4

Class 3b and 4

Question 5

What is used to characterize lasers?

Answer 5

Wavelength, power, output, tissue exposure time

Question 6

Can you use the same protective gear for every laser?

Answer 6

No, lasers have differing optical densities

Question 7

How can you protect an ETT from laser combustion?

Answer 7

Wrap in saline-soaked gauze or sponges

Question 8

How can fire hazard be minimized during laser procedures?

Answer 8

Spontaneous breathing of room air, lower FiO2, injectable anesthetic techniques, nasotracheal intubation, tracheostomy

Question 9

List the potential consequences of inhaled laser smoke

Answer 9

Atelectasis, bronchoconstriction, bronchospasm, alveolar edema, interstitial pneumonia, carcinogen exposure

Question 10

How is ionizing radiation hazardous?

Answer 10

Causes injury at the cellular level by transferring high levels of energy into atoms and molecules such as DNA, RNA, and other cellular proteins, damaging chemical bonds, and altering electrical charge to create free radicals or ions

Question 11

What cells are most sensitive to the effects of ionizing radiation?

Answer 11

Rapidly dividing cells (bone marrow, reproductive, SI, skin)

Question 12

What cells are least sensitive to effects of ionizing radiation?

Answer 12

Muscle and nerve

Question 13

What effects of chronic radiation exposure are anesthesia providers most susceptible to?

Answer 13

Aging, cataracts, SCC, leukemia

Question 14

How is ALARA achieved?

Answer 14

Increased distance, shielding, decreased exposure time, minimize image number

Question 15

What is the primary source of personnel occupational exposure to x-rays?

Answer 15

Scatter from the patient (x-rays that bounce or scatter from objects in the path of the primary beam)

Question 16

What pregnancy time period is most at risk to radiation exposure?

Answer 16

First 16 weeks

Question 17

How is fetal radiation exposure monitored?

Answer 17

Dosimeter badge at waist under lead

Question 18

What’s the gestation radiation limit?

Answer 18

10% of normal

Question 19

Minimum anesthesia/sedation monitoring for radiology

Answer 19

HR, RR and RE, pulse palpation (quality and rate), MM color, NIBP

Question 20

True or False: The ETT radio-opaque stripe causes CT artifact

Answer 20

True

Question 21

How is contrast extravasation treated?

Answer 21

Flush area with saline, cold compress, hyaluronidase to increase absorption, symptomatic therapy

Question 22

How can reduced renal function be reversed after contrast?

Answer 22

Correct hypotension and administer IVF

Question 23

5-Gauss Line

Answer 23

Line behind which no ferromagnetic objects are allowed

Question 24

What is the most significant hazard when working in a magnetic environment?

Answer 24

Projectile or missile effect

Question 25

What implanted materials can be safely imaged with MRI and when?

Answer 25

CV coils and stents, microchips, vascular clamps

Six weeks after placement when there is adequate scarring

Question 26

How are burns prevented in the magnet?

Answer 26

Lines should run straight (no loops) and parallel to bore, no transdermal patches

Question 27

Quench

Answer 27

Supercooled liquid gas/cryogen, usually helium, is used to control the energy generated by MR. With a quench, magnetic field is lost and explosion is released through vent pipe under emergency conditions (fire, patient trapped in magnet by missile effect). Frostbite or asphyxiation can occur if vent pipe fails.

Question 28

ECG in MRI

Answer 28

Gradient magnetic fileds/frequencies can make unreadable

T or ST segment may be elevated due to superimposed voltages generated by aortic blood flow in magnetic field

Carbon graphite patches used

Question 29

GBCAs

Answer 29

Gadolinium-based contrast agents are excreted predominantly unchanged by the kidneys. Brady or tachycardia, hypo and hypertension can result. Atopic dogs are more likely to have a reaction. Can be given IM if no IV route available.