Radiation/Laser Safety - Exam 1 Flashcards
1
Q
Types of Radiation
Electromagnetic:
A
- from motion of atoms
- combines electricity & magnetim
- electrons changing orbits
- ex: x-rays, light rays
2
Q
Types of Radiation
Mechanical
A
- only travels through substances - not air
3
Q
Types of Radiation
Nuclear (neutron)
A
- comes from unstable atom nuclei
- ex: nuclear plants
4
Q
Types of Radiation
Cosmic (beta)
A
- involves electrons only
- ex: sun rays - travels @ speed of light almost
5
Q
Non-ionizing radiation:
A
- stable form
- does not knock electrons off atoms
- does not break molecular bonds
- only harmful d/t heat energy (microwaves/radiowaves)
6
Q
Ionizing Radiation:
A
- more harmful
- electrons are knocked off atoms
- they create ions
- the electrical charges cause intracellular chemical reactions
7
Q
What are the 3 cellular risks w/ ionizing radiation?
A
- break DNA chains (cell death - apoptosis)
- mutate DNA chains - cancer
- Mutated sperm or egg cell - birth defects
8
Q
Are x-rays or light rays stronger?
which one has more energy?
which one has longer wavelength?
A
- x-rays stronger
- x-rays more energy/shorter wavelength
- light rays have longer wavelength
9
Q
X-rays are carried by particles called ________.
A
- photons (light particles)
10
Q
How is light emitted w/ x-rays?
A
- electrons orbit the atom in a resting state
- they are heated and excited
- jump to higher energy orbit
- when they fall back down to the lower orbit - release photons (what we see as light)
11
Q
Are small or large atoms more likely to absorb photons from x-ray?
A
large atoms
* greater energy differences b/w orbits
* lighter/brighter image on x-ray
* ex: bones, dense tissue
12
Q
What are examples of tissue consisting of small atoms?
A
- soft tissue
- they don’t absorb as many photons on x-ray b/c smaller movement of electrons
- gray on x-ray
13
Q
x-ray machine
What does the cathode do?
A
- heated filament in the middle
- heat causes electrons to fly off filament
14
Q
x-ray machine
what does the anode do?
A
- made of tungsten (positively charged)
- attracts electrons across tube
15
Q
x-ray machine
how do photons escape the machine through the window?
A
- as anode attracts the electrons - photons are released as energy
- makes the x-ray beam
16
Q
x-ray machine
how is an image created?
A
chemical reaction on film
* tissue absorbs photons in a way that reflects the image
* small atoms vs. large atoms
17
Q
x-ray machine
what 2 things can affect the image quality?
A
- ambient light can darken/lighten image
- intensity changes to beam
- over exposure: dark, obliterates structures
- under exposure: white, exaggerates structures
18
Q
What are 4 Diagnostic uses for x-rays?
A
- radiography (bone fx, tube placement, foreign objects)
- mammography
- computed tomography (x-ray w/ computer processing)
- fluoroscopy - real time images, high radiation amounts
19
Q
Diagnostics x-ray
Examples of Fluoroscopy uses:
A
- stent placement
- CBD stent
- aneurysm coils
- ortho/neurosurgery
20
Q
What is a therapeutic use for radiation?
A
- radiation therapy
- damages cancer cell DNA
- creates ions w/ electrical charge - intracellular chemical reactions - breaks cancer cell DNA chains
21
Q
Radiation Therapy SE
Hair loss:
A
anything above the waist
22
Q
Radiation therapy SE
diarrhea/urinary changes:
A
anything below the chest (pelvis, rectum, abdomen)
23
Q
Radiation SE:
n/v:
A
brain: chemoreceptor trigger zone
* pelvis, abdomen
24
Q
radiation SE:
Sexual problems/infertility:
A
- pelvis/rectum
25
# Radiation SE
Fatigue:
Brain, Breast, Chest, Head/neck, pelvis, rectum, abdomen
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# Radiation SE
dysphagia:
* chest
* Head/neck
27
# radiation doses
what is a REM?
* radiation dose times a weighted factor
* nearly ~ to a Rad
* measured as millirem (mrem) 1/1000 of a Rem
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# Allowable yearly mrem doses
whole body:
* 5,000 mrem
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# Allowable yearly mrem doses
extremities:
50,000
30
# Allowable yearly mrem doses
lens of eye:
15,000
31
# allowable yearly mrem doses
pregnancy
* 500mrem after 2nd trimester
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CXR mrem:
5-10mrem
* could be more w/ scatter and old machines
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coronary angiogram mrem:
* 1,500 mrem
* done under fluoro
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angioplasty mrem
* 5,700 mrem
35
CT mrem:
* 5,000 mrem
36
# Indirect sources of Radiation
What is scatter?
* incidental radiation that projects across the room
* reflected off tables, patients, other surfaces
37
# Scatter -
What is collimation?
how does it affect scatter?
* has to do w/ how wide the window is that photons are escaping through
* wider beam = more collimation/scatter
38
What things can increase scatter?
* wider beam window (increased collimation)
* obese pts
* bigger areas being x-rayed
* increased distance b/w pt and machine
39
What was the only symptom noticed in studies w/ 200,000 mrem exposure?
* transient erythema
* fetal doses < 10,000 mrem unlikely to cause effects after 20 weeks
40
Where are dosimeters worn?
* outside apron on collar
* inside apron on waist
40
# Radiation Protection as low as Reasonably Achievable (ALARA)
What 4 things can providers do to decrease exposure to radiation?
1. reduce time spent near beam entry
2. distance: double distance from beam = cut exposure by 3/4
3. scatter: be > 6ft from pt
4. Shielding: lead aprons, portable shields, thyroid shield, lead glasses
41
What 3 things should we not do w/ our dosimeters?
1. mix up inside vs. outside
2. share w/ others
3. don't leave in car on dash/seat - absorbs heat from cosmic rays = higher reading
42
What form of radiation does MRI use?
non-ionizing
43
Principles of MRI:
________ ________ used to orient nuclei of ________ to north-south poles.
* magnetic field
* hydrogen molecules
* **radiowave pulses change orientation of specific atoms which radiates energy**
44
What generates the contrast in MRI?
* the time until tissue relaxation occurs when RF waves turn off
* affected by: densities of hydrogen nuclei in tissues, chemical & phys properties
45
T1 view:
Magnetic Vector relaxes
* fat bright, water dark
* **gray-white matter contrast & normal anatomy**
46
T2 View:
Axial spin relaxes
* Fat dark, water bright
* **identifies tissue edema & pathology**
47
# MRI contrast
How does Gadolinium work?
* alters the magnetic properties of nearby water molecules = enhanced image
48
SE of Gadolinium
Clearance:
* itching, rash, warm skin sensation (benadryl)
* normal GFR - 24 hrs
49
# Magnetic Field
What 2 things do ferromagnetic objects experience?
* attractive force
* high degree of Torque (line up w/ magnetic field)
* **field always on**
50
What are 4 risks of MRI?
* projectile risk
* RF energy causes tissue/device heating
* electromagnetic interference w/ EKG (artifact)
* Acoustic noise: 125dB (chainsaw) = hearing protection
51
What are 2 typical options for providing anesthesia in MRI?
What is our goal?
* Sevoflurane - MRI safe volatile
* TIVA - opioids not needed
* **minimize movement**
52
AANA Standards & MRI
1. normal monitors: EKG, BP, pulse-ox, capnography
2. have airway equip. available
3. suction available
4. MRI pumps or long tubing!
5. laryngoscope handles, blades = induce in different room
53
MRI patient position concerns
* head/neck:
* abdominal scans:
* head/neck: airway inaccessible, stop scan if needed
* abdomen: brachial plexus injuries b/c arms over head (padding)
54
# Provider Safety
What medical devices are not MRI safe?
* Pacemakers
* AICDs
* Implanted insulin pumps
55
# Provider safety:
What medical devices are MRI safe?
* heart valves
* endovascular, biliary stents (8 weeks)
* coronary stents
* vascular ports, IVC filters
* ortho implants
56
# Provider Safety
What can rapid movement toward the magnetic field cause?
**(>1m/sec)**
* dizziness
* HA
* light flashes
* nausea
57
What does LASER stand for?
How is the beam?
* Light Amplification by Stimulated Emission of Radiation
* **focused narrow beam, high-intensity**
58
What 5 types of surgery commonly use LASER?
1. Cosmetic: minimal scarring
2. LASIK
3. dental
4. general (condyloma, TURP)
5. ENT: precise areas (sinuses, tracheal tumor)
59
How does the LASER work?
* electrons excited from energy source
* move to higher orbit
* return to ground state
* release photons of energy
**electromagnetic radiation**
## Footnote
more concentrated than x-ray
60
# Properties of Laser Radiation
monochromatic:
* all photons in laser beam are same wavelength
61
# Properties of Laser Radiation
Coherence:
* the travel of photons is synchronized in time and space
* no random movement
62
# Properties of Laser Radiation
Collimation:
* laser beam photons are nearly parallel
* beam is focused on small area w/ no scatter
63
# Properties of Laser Radiation
What are 6 advantages of using LASER?
* excellent precision
* good hemostasis
* rapid healing
* less scar formation
* less post-op edema/pain
* lower infection rates
64
# Lasing Medium
What is **argon** LASER used for?
* modest tissue penetration (superficial)
* 0.05-2mm deep
* **dermatology**
65
# Lasing Medium
What is **Carbon Dioxide** LASER used for?
* scatter minimal
* surrounding tissue damage negligible
* **great for vocal cords/oropharynx**
66
# Lasing Medium
What is the **Nd:YAG** LASER used for?
* most powerful
* more heat
* deeper tissue penetration (2-6mm)
* **tumor debulking**
67
What are 5 Hazards of LASER?
1. **atmospheric contamination**: lesion lasered - particles vaporized and breathed in/colonized (condyloma)
2. perforation of vessel/structure
3. embolism (entrain air if vessel perf)
4. inappropriate energy transfer
5. **airway fire**
68
What are the symptoms of inhaling particulate?
* HA, nausea (immediately)
* can cause: interstitial pneumonia, bronchiolitis, emphysema
* carcinogenic!
69
Generic Laser Safety:
* laser glasses for provider & pt w/ eyes taped
* windows covered
* laser plume masks
* suction
* water/saline irrigation - fire risk
* don't tent drapes
70
What is the "fire triad"?
1. ignition source: laser, ESU
2. fuel: drapes, gauze dressings, ETT, gel mattress pads, facial/body hair
3. oxidizer - keep O2 levels lower w/ laser (O2, nitrous, air)
71
What Airway Fire Safety things can we do?
* laser-resistant ETTs
* low FiO2 (21% if possible)
* wet pledgets around ETT
* methylene blue in ETT cuff - rupture sign (no fire prevention)
* use scissors to cut into trachea instead of bovie
* remove ETT during laser procedure and reinsert PRN sats
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