The Nuclear Incident

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The Nuclear Incident

• Management of Nuclear Casualties

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Hospital Management of Nuclear Casualties
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Terminal Objective

• Be able to describe the various types of
  radiological hazards.
• Become familiar with the acute health effects
  from radiation contamination and exposure.
• Become familiar with the principles of diagnosis,
  treatment and management of radiation casualties.

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Radiological and Nuclear Devices

• Simple radiological device
• Radiological dispersal device
• Reactor
• Improvised nuclear device
• Nuclear weapon

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The Basics of Radiation

• Ionizing radiation is electromagnetic energy or
  energetic particles emitted from a source.
• Ionizing radiation is able to strip electrons
  from atoms causing chemical changes in molecules.

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The Basics of Radiation
Biological Molecular Damage
Biological Damage
Chemical Damage Free Radicals 10-10 Seconds
1. Proteins 2. Membrane 3. DNA
Cells, tissues, whole animals Hours to years
Seconds to hours
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Ionizing Radiation - Alpha

• 2 neutrons and 2 protons
• Highly ionizing
• Travels several centimeters in air and a few
  microns in tissue
• Component of nuclear fallout
• Stopped by a thin paper or clothing
• Threat is inhalation or absorption of alpha
  emitter in wounds

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Ionizing Radiation - Beta

• High energy electron emitted from nucleus
• Can have wide range of energies depending upon
  the particular radionuclide
• Moderately penetrating
• Up to a few meters in air
• Millimeters in tissue

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Gamma or X-Ray (Photons)

• High energy rays
• Very penetrating
• Difficult to shield
• Can be produced from radioactive decay and a
  nuclear weapon explosion or reactor accident

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Ionizing Radiation - Neutrons

• Neutral particle emitted from the nucleus
• Can be very penetrating
• Requires special consideration for shielding

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Examples of Radioactive Materials
Substance Half Life Emit Use Americium 241 458
years a, g Smoke Detectors Cobalt 60 5.3 years b,
g Medical Therapy Plutonium 238 86.4
years a Thermoelectric Gen. Plutonium 239 24,400
yrs a Reactors and Weapons Radium 226 1,602
yrs a Medical Therapy Uranium 238 millions yrs a,
b, g Reactors and Weapons Iridium 192 74 days b,
g Industrial Radiography
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Radiation Half-Life

• Time required for a radioactive substance to lose
  half of its radioactivity
• Each radionuclide has a unique half-life
• Half-lives range from extremely short (fraction
  of a second) to millions of years
• Examples
• Tc-99m 6.0 hrs
• I-131 8.05 days
• Co-60 5.26 yrs
• Sr-90 28.1 yrs
• Pu-239 24,400 yrs
• U-238 4,150,000,000 yrs

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Radiation - Units of Measure

• rad - basic unit for measuring radiation
• rem - quantifies the amount of damage that is
  suspected from a particular type of radiation dose

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Radiation Doses in Perspective

• Natural background and manmade radiation
  360 mrem / yr
• Diagnostic chest x-ray
  10 mrem
• Flight from LA to Paris
  4.8 mrem
• Barium enema 800
  mrem
• Smoking 1.5 ppd 16,000 mrem /
  yr
• Heart catheterization 45,000 mrem
• Mild acute radiation sickness
  200,000 mrem
• LD50 for irradiation
  450,000 mrem

mrem millirem 1/1000 of a rem
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Types of Radiation Exposure

• External irradiation - whole-body or partial-body
• Contamination by radioactive materials - external
  (deposited on the skin) or internal (inhaled,
  swallowed, absorbed through skin, or introduced
  through wounds)
• Incorporation of radioactive materials - uptake
  by body cells, tissues, or organs (bone, liver,
  kidney, etc)
• Combined radiation injury - combination of the
  above complicated by trauma.

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Radiation Injury - External Irradiation


s

Partial Body

Local


Whole Body
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Radiation Injury - Contamination
Internal
External
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Radiation Injury - Incorporation
Thyroid
Lung
Liver
Bone
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Radiation - LD50

• We know what radiations are produced
• We know how to measure them
• But the body senses cannot detect radiation.
  Therefore, how can we measure the biological
  damage?
• LD50/30 Animals
• LD50/60 Human

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Examples of LD50 for Given Species

• Species Dose (rads)
• Guinea Pigs 250 LD 50/30
• Goat 350 LD 50/30
• Man 250-450 (LD 50/60)
• Mouse 570 LD 50/30
• Rat 550-800 LD 50/30
• Frog 700 LD 50/30
• Snail 8,000-20,000 LD 50/30

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Severity of Injury

• The higher the dose, the more severe the early
  effects and the greater the possibility of
  delayed effects

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Acute Radiation Syndrome (ARS)

• Group of symptoms that develop after total body
  irradiation (gt 100 rads)
• May occur from either internal or external
  radiation
• Four important factors are
• High Dose
• High Dose Rate
• Whole Body Exposure
• Penetrating Radiation

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ARS - Phases

• Prodromal Phase - occurs in the first 48 to 72
  fours post-exposure and is characterized by
  nausea, vomiting, and anorexia. At doses below
  about 500 rads last 2 to 4 days.
• Latent Phase - follows the prodromal phase and
  lasts for approximately 2 to 2 1/2 weeks. During
  this time, critical cell populations (leukocytes,
  platelets) are decreasing as a result of bone
  marrow insult. The time interval decreases as
  the dose increases.
• Illness Phase - period when overt illness
  develops
• Recovery or Death Phase - may take weeks or months

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ARS - Hematopoitic SystemBlood Count
RBC
Cell Reduction
Neutrophils
Lymphocytes
Platelets
24-hr
1 week
2 weeks
3 weeks
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ARS - Hematopoietic Syndrome
3.0
2.5
Normal Range
2.0
Absolute Lymphocytes (109/L)
1.5
Moderate
1.0
Severe
Patient
Injury
0.5
Very Severe
0.1
Lethal
0
3
6
17
24
48 hrs
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ARS - Gastrointestinal Syndrome

• Radiation gt 600 rads
• Damages intestinal lining
• Nausea and vomiting within the first 2 - 4 hours
• May develop diarrhea
• Associated with sepsis and opportunistic
  infections
• At 10 days could develop bloody diarrhea
  resulting in death

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ARS - Central Nervous System

• Seen with radiation dose gt 1,000 rads
• Microvascular leaks Õ edema
• Elevated intracranial pressure
• Death within hours

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ARS - Skin
Dry Desquamation
Moist Desquamation
Erythema
Necrosis
Epilation
Response
300 600 1000 gt1500 gt5000
Dose
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ARS Trauma

• Radiation and Trauma á Mortality
• Trauma is the first priority

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Treatment

• Wound and burn care, surgery, and orthopedic
  repair should be done in the first 48 hours or
  delayed for 2 to 3 months

Emergency Surgery
Hemopoietic Recovery No Surgery
Surgery Permitted
24 - 48 Hours
After 3 Months
3 Months
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Survival Time
Survival Time
Hematopoietic
Gastrointestinal
CNS/ CVS
200 Rads
1000 Rads
100,000 Rads
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Classification, Treatment Disposition

• Patients are classified in three categories based
  on signs and symptoms
• Survival probable lt 100 rads
• Survival possible 200 - 800 rads
• Survival improbable gt 800 rads

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Classification, Treatment Disposition
Incorporation / Internal Contamination

• Various medications can be used to limit uptake
  or facilitate removal of radioactive material
• Numerous medications are approved by the FDA.
  Certain drugs are investigational and can be used
  in an emergency (i.e. Radiogardase Prussian
  Blue and DTPA)
• NCRP 65

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Radiation Protection Principles

• Time
• Distance
• Shielding

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Key Points

• No antidote for radiation exposure - treatment is
  primarily supportive
• Minimal risk to responding personnel from
  radiation contaminated patients
• Early symptoms are an indication of the severity
  of the radiation dose
• Consult with specialists for survivable groups
• Treat life-threatening injuries first