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 CONCEPTUAL DISPERSAL DEVICE SHIELDED CONTAINER RADIOACTIVE MATERIAL HIGH EXPLOSIVE • Simple radiological device • Radiological dispersal device • Reactor • Improvised nuclear device • Nuclear weapon 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 Biological Molecular Damage Biological Damage 1. Proteins 2. Membrane 3. DNA Cells, tissues, whole animals Hours to years 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 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 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 I-131 Co-60 Sr-90 Pu-239 U-238 6.0 hrs 8.05 days 5.26 yrs 28.1 yrs 24,400 yrs 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 Heart catheterization 16,000 mrem / yr 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 Partial Local Body DPT 8.0 Whole Body Radiation Injury - Contamination External Internal DPT 8.0 Radiation Injury - Incorporation Thyroid Lung Liver Bone 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 postexposure 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 System Blood Count RBC Cell Reduction Neutrophils Lymphocytes Platelets 24-hr 1 week 2 weeks 3 weeks DPT 8.0 Absolute Lymphocytes (109/L) ARS - Hematopoietic Syndrome 3.0 2.5 Normal Range 2.0 1.5 Moderate 1.0 Severe Patient 0.5 0.1 0 3 6 17 24 48 hrs Very Severe Lethal DPT 8.0 Injury 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 Response 300 600 Necrosis Moist Desquamation ARS - Skin 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 Emergency Surgery Hemopoietic Recovery No Surgery Surgery Permitted 24 - 48 Hours 3 Months After 3 Months DPT 8.0 Survival Time Survival Time Hematopoietic Gastrointestinal CNS/ CVS 200 Rads 1000 Rads 100,000 Rads 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 DPT 8.0