DPT 8.0

The Nuclear Incident

Management of Nuclear Casualties

DPT 8.0

Hospital Management of Nuclear Casualties

DPT 8.0

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.

DPT 8.0

Radiological and Nuclear Devices

• Simple radiological device

• Radiological dispersal device

• Reactor

• Improvised nuclear device

• Nuclear weapon

CONCEPTUAL DISPERSAL DEVICE

HIGH EXPLOSIV

E

SHIELDED CONTAINER

RADIOACTIVE MATERIAL

DPT 8.0

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.

DPT 8.0

The Basics of Radiation

Chemical Damage

Free Radicals

10-10 Seconds

1. Proteins2. Membrane3. DNA

Biological Molecular Damage

Cells, tissues,whole animals

Hours to years

BiologicalDamage

Seconds to hours

DPT 8.0

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

DPT 8.0

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

DPT 8.0

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

DPT 8.0

Ionizing Radiation - Neutrons

• Neutral particle emitted from the nucleus

• Can be very penetrating

• Requires special consideration for shielding

DPT 8.0

Substance Half Life Emit Use

Americium 241 458 years , Smoke Detectors

Cobalt 60 5.3 years , Medical Therapy

Plutonium 238 86.4 years Thermoelectric Gen.

Plutonium 239 24,400 yrs Reactors and Weapons

Radium 226 1,602 yrs Medical Therapy

Uranium 238 millions yrs , Reactors and Weapons

Iridium 192 74 days , Industrial Radiography

Examples of Radioactive Materials

DPT 8.0

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 hrsI-131 8.05 daysCo-60 5.26 yrsSr-90 28.1 yrsPu-239 24,400 yrsU-238 4,150,000,000 yrs

DPT 8.0

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

DPT 8.0

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

DPT 8.0

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.

DPT 8.0

Radiation Injury - External Irradiation

s

Local PartialBody

WholeBody

DPT 8.0

Radiation Injury - Contamination

InternalExternal

DPT 8.0

Radiation Injury - Incorporation

ThyroidLung

LiverBone

DPT 8.0

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

DPT 8.0

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

DPT 8.0

Severity of Injury

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

effects

DPT 8.0

Acute Radiation Syndrome (ARS)

• Group of symptoms that develop after total body irradiation (> 100 rads)

• May occur from either internal or external radiation

• Four important factors are:– High Dose

– High Dose Rate

– Whole Body Exposure

– Penetrating Radiation

DPT 8.0

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

DPT 8.0

ARS - Hematopoitic SystemBlood Count

24-hr 1 week 2 weeks 3 weeks

Lymphocytes

Neutrophils

Platelets

RBC

Cell Reduction

DPT 8.0

ARS - Hematopoietic Syndrome

3.0

2.5

2.0

1.5

1.0

0.5

0.10 3 6 17 24 48 hrs

Normal Range

Moderate

Severe

Very SevereLethal

Injury

Abs

olut

e Ly

mph

ocyt

es (

109/L

)

Patient

DPT 8.0

ARS - Gastrointestinal Syndrome

• Radiation > 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

DPT 8.0

ARS - Central Nervous System

• Seen with radiation dose > 1,000 rads

• Microvascular leaks edema

• Elevated intracranial pressure

• Death within hours

DPT 8.0

ARS - Skin

ResponseE

pila

tion

Ery

them

a

Dry

Des

quam

atio

n

Moi

stD

esqu

amat

ion

Nec

rosi

s

300 600 1000 >1500 >5000

Dose

DPT 8.0

ARS & Trauma

• Radiation and Trauma = Mortality

• Trauma is the first priority

DPT 8.0

Treatment

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

24 - 48 Hours 3 Months

EmergencySurgery

Hemopoietic RecoveryNo Surgery

After 3 Months

SurgeryPermitted

DPT 8.0

Survival Time

200 Rads 1000 Rads 100,000 Rads

Hematopoietic

Gastrointestinal

CNS/ CVS

SurvivalTime

DPT 8.0

Classification, Treatment & Disposition

• Patients are classified in three categories based

on signs and symptoms:

– Survival probable < 100 rads

– Survival possible 200 - 800 rads

– Survival improbable > 800 rads

DPT 8.0

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

DPT 8.0

Radiation Protection Principles

• Time

• Distance

• Shielding

DPT 8.0

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