Presentation on theme: "Medical Response to Nuclear and Radiological Terrorism"— Presentation transcript:
1 Medical Response to Nuclear and Radiological Terrorism Stevan Cordas DO MPHClinical Associate Professor TCOM/UNTHSC
2 Consultant Texas Department of Health - WMD Education Consultant American Osteopathic Association – Washington Bureau – WMDCertified Occupational Medicine (Toxicology)Trained in Cleveland Institute of Nuclear MedicineFormer U.S. Army Medical CorpsSteering Committee - Medical Reserve Corps (Dallas, Tarrant, Denton and Collins County)Author of WMD – AOA DO-online for CME
3 What Is Radiation?Radiation is energy transported in the form of particles or waves.Radiation is energy moving in the form of particles or waves.
4 Exposure Vs. Contamination Exposure: irradiation of the body absorbed dose (Gray, rad)Contamination: radioactive material on patient (external)or within patient (internal)Exposure: irradiation from outside the bodyRadioactive Contamination: radioactive material where it does not belong. It is often attached to dust or dirt.External contamination – outside the body (on skin or clothes)can usually be easily washed offInternal contamination – inside the body (taken in through inhalation, ingestion or wounds)usually passes through the body through the normal cleansing mechanismsContamination can be composed of any radioactive material (perhaps several at once) and the radiation emitted from it can be of any type (usually a combination of alpha, beta or gamma).Contamination can be a solid material, a liquid or a gas. Sometimes it is in the form of dust particles that float through the air and eventually settle to the ground (or some other surface.)For example, patients who have a procedure, such as an x-ray or CT scan, have been exposed to radiation but are not contaminated and do not pose any radiation contamination or exposure potential for hospital personnel.
5 Radioactive material – can come in any form, including particles similar to dust.
6 Penetration Abilities of Different Types of Radiation Alpha ParticlesStopped by a sheet of paperRadiationSourceBeta ParticlesStopped by a layer of clothingor less than an inch of a substance (e.g. plastic)Gamma RaysStopped by inches to feet of concreteor less than an inch of leadAlpha particles. Alpha particles do not penetrate the dead layer of skin and can be stopped by a thin layer of paper or clothing. If an alpha emitting radioactive material gets inside the body through inhalation, ingestion, or through a wound, the emitted alpha particles can cause ionization that results in damage to tissue.Beta particles. Depending on its energy, beta radiation can travel from inches to many feet in air and is only moderately penetrating in other materials. Some beta radiation can penetrate human skin to the layer where new skin cells are produced. If high enough quantities of beta emitting contaminants are allowed to remain on the skin for a prolonged period of time, they may cause skin injury. Beta emitting contaminants may be harmful if deposited internally. Protective clothing (e.g., universal precautions) typically provides sufficient protection against most external beta radiation.Gamma rays and x-rays (photons). Gamma rays and x-rays are able to travel many feet in air and many inches in human tissue. They readily penetrate most materials. Thick layers of dense materials are needed to shield against gamma radiation. Protective clothing provides little shielding from gamma and x radiation, but will prevent contamination of the skin with the gamma emitting radioactive material.Neutrons. Neutrons also penetrate most materials. They are able to travel many feet in concrete and thousands of feet in air. Thick layers of materials with lots of hydrogen in them (like water or concrete) are needed to shield against neutron radiation. Protective clothing provides no shielding from neutron radiation. Neutrons are not likely to be encountered except in the initial seconds of a nuclear criticality event.NeutronsStopped by a few feet of concreteCDC
7 Radiation Units Measure of Amount of radioactive material Ionization in airAbsorbed energy per massAbsorbed doseweighted by type of radiationUnitcurie (Ci)roentgen (R)radremQuantityActivityExposureAbsorbed DoseDose Equivalent7. Radiation UnitsA curie is a very large amount of radioactivity. Contamination of individuals usually involve µCi to mCi quantities. Nuclear medicine patients are injected with µCi to mCi quantities of radioactive material for routine diagnostic exams.The basic unit of radiation dose is the rad. The rad is defined as the deposition of 0.01 joule of energy (a small amount) per kilogram (kg) of tissue.A rad of x-rays, a rad of gamma rays, and a rad of beta particles are about equally damaging to tissue. However, a rad of another type of ionizing radiation, such as alpha particles or neutrons, is much more damaging to tissue than a rad of gamma rays.The rem was introduced to take into account this variation in tissue damage. This is important because a person may be exposed to more than one type of radiation. For example, it was found that 100 rad of gamma and beta radiation produced the same effect as 100 rad of x-rays. However, only 20 rad of neutrons and 5 rad of alpha particles produced the same effect as 100 rad of x-rays. Therefore, neutron and alpha radiations were more potent and required fewer rad to produce the same effect.The number of rem is calculated by multiplying the number of rad by a radiation weighting factor that accounts for the relative amount of biological damage produced by a specific type of radiation. The radiation weighting factor for x-rays, gamma rays, and beta particles is 1. Thus, a rad of one of these radiations is equal to one rem. For other types of radiation (that are less likely to be present in accidents), the quality factor may be higher.The International Scientific System (SI) assigns different units to the quantities:1 R = 2.58 X 10-4 C kg-1 1 gray (Gy) = 100 rad1 sievert (Sv) = 100 rem 1 becquerel (Bq) = 1 disintegration per second
8 A Gray (Gy)The Gray (Gy) is a unit of absorbed dose and reflects an amount of energy deposited into a mass of tissue (1 Gy = 100 rads). In this lecture, the absorbed dose we are referring to is that dose inside the patient's body (i.e., the dose which is normally measured with personal dosimeters). For most purposes, one rem equal one rad. One mrem is one thousandth of one rem and is a common means of expressing radiation.
9 Radiation Doses and Dose Limits Flight from Los Angeles to London mremAnnual public dose limit mremAnnual natural background mremFetal dose limit mremBarium enema mremAnnual radiation worker dose limit 5,000 mremHeart catheterization (skin dose) ,000 mremLife saving actions guidance (NCRP-116) ,000 mremMild acute radiation syndrome ,000 mremLD50/60 for humans (bone marrow dose) ,000 mremRadiation therapy (localized & fractionated) ,000,000 mrem9. Radiation Doses and Dose LimitsRadioactive material has always been a natural part of the earth. It has existed for millions of years in the crust of the earth, in building materials, in the food we eat, the air we breathe, and in nearly everything that surrounds us. Radiation from these materials, as well as cosmic radiation from the sun and universe, makes up the natural background radiation to which we are constantly exposed. On the average, persons are exposed to about 300 millirem per year from natural sources (NCRP Report No. 101).The guidance from NCRP Report No. 116, Limitation of Exposure to Ionizing Radiation, states that for life saving or equivalent purposes, workers may approach or exceed 50,000 mrem to a large portion of the body. Emergency exposures are considered once-in-a-lifetime. This is below the threshold for the acute radiation syndrome, discussed later.If an individual is exposed to more than 100 rem at one time, predictable signs and symptoms will develop within a few hours, days, or weeks depending on the magnitude of the dose. About half of all people exposed to a single dose of 350 rem will die within 60 days (LD50/60) without medical intervention. The large doses used in medicine for radiation therapy, while higher than this dose, are given to only part of the body and are typically given over a period of weeks.Heart catheterization is a skin dose; barium enema is an effective dose. (NRPB Report R-200, 1986)
10 Radioactive MaterialRadioactive material consists of atoms with unstable nucleiThe atoms spontaneously change (decay) to more stable forms and emit radiationA person who is contaminated has radioactive material on their skin or inside their body (e.g., inhalation, ingestion or wound contamination)10. Radioactive MaterialThe difference between radioactive material and radiation should be explained.Radioactivity is a mechanism whereby an unstable nucleus rearranges itself to become more stable. The process often involves the ejection of charged particles from the atomic nuclei. This ejection of particles (beta or alpha) is often accompanied by the emission of gamma rays from the nucleus or x-rays from the atom’s electron shells. Beta particles, alpha particles, gamma rays and x-rays are all forms of radiation that can be emitted from radioactive atoms.Radioactive contamination is simply radioactive material (often attached to dust or dirt) that is either on the skin or clothes of the patient or has been taken into the body via inhalation, ingestion, or through a wound.Usually most of the external contamination can be removed from the patient by carefully removing the patient’s clothing.
11 Half-life (HL) Physical Half-Life Time (in minutes, hours, days or years) required for the activity of a radioactive material to decrease by one half due to radioactive decayBiological Half-LifeTime required for the body to eliminate half of the radioactive material (depends on the chemical form)11. Half-LifeIn any sample of radioactive material, the amount of radioactive material constantly decreases with time because of radioactive decay.The physical half-life is the amount of time required for a given amount of radioactive material to be reduced to half the initial amount by radioactive decay.The biological half-life is the time required for the human body to eliminate half of the radioactive material taken into it. For many radioactive materials, the elimination from the body occurs via urination. However, depending on the chemical composition of the radioactive material, other pathways can also help to eliminate the radioactive material from the body.The effective half-life is a measure of the time it takes for half the radioactive material taken into the body to disappear from the body. Both the physical half-life and the biological half-life contribute to the elimination of the radioactive material from the body. The combination of these two half-lives is called the effective half-life.After one half-life, half of the material remains. After a second half-life, a half of a half, i.e. 25% of the initial amount remains. After 10 half-lives, about 1/1000 remains. After 20 half-lives, only one millionth of the material remains.
12 Effective Half-lifeThe net effect of the combination of the physical & biological half-lives in removing the radioactive material from the bodyHalf-lives range from fractions of seconds to millions of years1 HL = 50% 2 HL = 25% 3 HL = 12.5%
13 Potential Types of Weapons Stolen nuclear material from a hospital, industry, university, power plant or disposal facilityCreation of a “dirty bomb” Generally thought to be the most likely scenario.Nuclear detonation from a device.Nuclear reactor sabotage13. Because of recent terrorist events, people have expressed concern about the possibility of a terrorist attack involving radioactive materials, possibly through the use of a “dirty bomb,” and the harmful effects of radiation from such an event. The Centers for Disease Control and Prevention has prepared this fact sheet to help people understand what a dirty bomb is and how it may affect their health.What a “dirty bomb” is A dirty bomb, or radiological dispersion device, is a bomb that combines conventional explosives, such as dynamite, with radioactive materials in the form of powder or pellets. The idea behind a dirty bomb is to blast radioactive material into the area around the explosion. This could possibly cause buildings and people to be exposed to radioactive material. The main purpose of a dirty bomb is to frighten people and make buildings or land unusable for a long period of time.Dirty bomb versus atomic bombs in Hiroshima and Nagasaki The atomic explosions that occurred in Hiroshima and Nagasaki were conventional nuclear weapons involving a fission reaction. A dirty bomb is designed to spread radioactive material and contaminate a small area. It does not include the fission products necessary to create a large blast like those seen in Hiroshima and Nagasaki.Sources of the radioactive material There has been a lot of speculation about where terrorists could get radioactive material to place in a dirty bomb. The most harmful radioactive materials are found in nuclear power plants and nuclear weapons sites. However, increased security at these facilities makes obtaining materials from them more difficult. Because of the dangerous and difficult aspects of obtaining high-level radioactive materials from a nuclear facility, there is a greater chance that the radioactive materials used in a dirty bomb would come from low-level radioactive sources. Low-level radioactive sources are found in hospitals, on construction sites, and at food irradiation plants. The sources in these areas are used to diagnose and treat illnesses, sterilize equipment, inspect welding seams, and irradiate food to kill harmful microbes.Dangers of a dirty bomb If low-level radioactive sources were to be used, the primary danger from a dirty bomb would be the blast itself. Gauging how much radiation might be present is difficult when the source of the radiation is unknown. However, at the levels created by most probable sources, not enough radiation would be present in a dirty bomb to cause severe illness from exposure to radiation.Past use of dirty bombs According to a United Nations report, Iraq tested a dirty bomb device in 1987 but found that the radiation levels were too low to cause significant damage. Thus, Iraq abandoned any further use of the device.What people should do following an explosion Radiation cannot be seen, smelled, felt, or tasted by humans. Therefore, if people are present at the scene of an explosion, they will not know whether radioactive materials were involved at the time of the explosion. If people are not too severely injured by the initial blast, they should:Leave the immediate area on foot. Do not panic. Do not take public or private transportation such as buses, subways, or cars because if radioactive materials were involved, they may contaminate cars or the public transportation system.Go inside the nearest building. Staying inside will reduce people's exposure to any radioactive material that may be on dust at the scene.Remove their clothes as soon as possible, place them in a plastic bag, and seal it. Removing clothing will remove most of the contamination caused by external exposure to radioactive materials. Saving the contaminated clothing would allow testing for exposure without invasive sampling.Take a shower or wash themselves as best they can. Washing will reduce the amount of radioactive contamination on the body and will effectively reduce total exposure.Be on the lookout for information. Once emergency personnel can assess the scene and the damage, they will be able to tell people whether radiation was involved.Even if people do not know whether radioactive materials were present, following these simple steps can help reduce their injury from other chemicals that might have been present in the blast.Taking potassium iodide (KI) Potassium iodide, also called KI, only protects a person's thyroid gland from exposure to radioactive iodine. KI will not protect a person from other radioactive materials or protect other parts of the body from exposure to radiation. It must be taken prior to exposure (for example, if people hear that a radioactive cloud is coming their way) or immediately after exposure to be effective. Since there is no way to know at the time of an incident whether radioactive iodine was used in the explosive device, taking KI would probably not be beneficial.Also, KI can be dangerous to some people. Taking KI is not recommended unless there is a risk of exposure to radioactive iodine.If radioactive materials were involved Keep televisions or radios tuned to local news networks. If a radioactive material was released, people will be told where to report for radiation monitoring and blood tests to determine whether they were exposed to the radiation as well as what steps to take to protect their health.Risk of cancer from a dirty bomb Some cancers can be caused by exposure to radiation. Being at the site where a dirty bomb exploded does not guarantee that people were exposed to the radioactive material. Until doctors are able to check people's skin with sensitive radiation detection devices, it will not be clear whether they were exposed. Just because people are near a radioactive source for a short time or get a small amount of radioactive material on them does not mean that they will get cancer. Doctors will be able to assess risks after the exposure level has been determined.
14 Hypothetical Suitcase Bomb 14. Shown is a hypothetical 1 kiloton IND (suitcase bomb).October 26, 1999: Rep. Curt Weldon, Chair of the House Subcommittee on Military Research and Development, shows a mockup “suitcase nuke” made from a U.S. nuclear artillery shell as Rep. Dan Burton looks on.CDCChairman Dan Burton Committee – Demonstration of example“suitcase nuke” made from US nuclear shell
15 Examples of Radioactive Materials Radionuclide Half-Life Activity UseCesium yrs x106 Ci Food IrradiatorCobalt yrs ,000 Ci Cancer TherapyPlutonium ,000 yrs Ci Nuclear WeaponIridium days Ci Industrial RadiographyHydrogen yrs Ci Exit SignsStrontium yrs Ci Eye Therapy Device15. Examples of Radioactive MaterialsRadioactive materials emit ionizing radiation. They are used in medical diagnosis (nuclear medicine), medical therapy (cancer treatment), industry (food irradiation), and for research.Many radioactive materials, including radioactive waste, are commercially shipped in special containers.A radionuclide is chemically identical to and behaves in the body the same way as the non-radioactive form of the element. For example, radioactive iodine (e.g. I-131) is concentrated in the thyroid in the same way as non-radioactive iodine (i.e. I-127).Quantities of radioactive material (i.e. activity) range from trivial amounts in typical laboratories, to much larger quantities, such as in nuclear reactors.Half-lives can range from seconds to millions of years.The nuclides that are in orange are those that are considered to be potential nuclides that could be present in a radiological dispersal device.
16 Examples of Radioactive Materials Iodine days Ci Nuclear Medicine TherapyTechnetium-99m hrs Ci Diagnostic ImagingAmericium yrs Ci Smoke DetectorsRadon days pCi/l Environmental Level
18 Types of Radiation Hazards External Exposure -whole-body or partial-body (no radiation hazard to EMS staff)Contaminated -external radioactive material: on the skininternal radioactive material: inhaled, swallowed, absorbed through skin or woundsInternalContaminationExternalContaminationExternalExposure18. Types of Radiation HazardsPatients who have only been exposed to the radiation from a radioactive source or a machine, such as an x-ray machine or a linear accelerator, are not contaminated and do not pose any radiation contamination or exposure potential for hospital personnel.Radiation safety precautions are not needed for patients who have only been exposed and are not contaminated.Patients with radioactive material on them or inside their bodies are said to be contaminated.Contaminated patients require care in handling to effectively remove and control the contamination.Analogy - You can think of radiation exposure and radioactive material in terms of a trip to the beach. Sand is like radioactivity. The sun is like radiation exposure. Once you go inside, you are not in the sun any longer and there is no more exposure (radiation stops). On the other hand, most of the sand came off when you walked off the beach, however, some sand remains on your skin until you physically remove it (brush or wash it off). The same is true for radioactivity contamination on the skin. A small amount may remain on the skin and need to be washed off.
19 Scope of Event Event Number of Deaths Most Deaths Due to Radiation None/FewRadiationAccidentRadioactiveFew/ModerateBlast TraumaDispersal(Depends onsize of explosion &19.. Scope of Event428 major radiation accidents have been reported worldwide in the years 1944 to These accidents caused 126 deaths due to radiation. Their effects were dependent on exposure, contamination and the number of people involved. There were an additional 8 non-radiation deaths that would likely have resulted in eventual death due to the radiation. (REAC/TS Registry, 2002)There have been no uses of radioactive dispersal devices. The outcome of such an event would depend on the size of the explosion, the radioactive material involved, the activity (amount) of the radioactive material, the number of people in the vicinity and the effectiveness of the emergency response.There have been no low-yield nuclear weapon detonations by terrorists. The outcome from such an event would depend on the yield, the location of the detonation and the number of people in the vicinity.Deviceproximity of persons)Low YieldLargeBlast TraumaNuclear Weapon(e.g. tens of thousands inThermal Burnsan urban area even fromRadiation Exposure0.1 kT weapon)Fallout(Depends on Distance)
21 Facility Preparation Activate hospital plan Obtain radiation survey metersCall for additional support: Staff from Nuclear Medicine, Radiation Oncology, Radiation Safety (Health Physics)Plan for decontamination of uninjured personsEstablish triage area21.. Facility PreparationThe hospital should activate its radiological emergency medical response plan.A triage area should be identified for accepting patients and the worried well.The plan should address contamination control for staff and facilities. There should be a call out list to obtain additional staff and equipment.Staff protects themselves from contamination by using universal precautions and double gloving.Staff should know where to obtain radiation survey meters and personnel to operate them.Environmental Services should establish multiple receptacles for contaminated waste.Call for additional support from hospital staff: Nuclear Medicine, Radiation Oncology, Radiation Safety/ Health Physics.Plan for the decontamination of uninjured persons away from the ED.Protect the floor with covering if time allows.
22 Develop Radiological Response Team Team Coordinator (leader)Emergency physician(s)Nurse (s)Triage OfficerAdministratorRadiation Safety OfficerMaintenancePublic Information OfficerSecurityLaboratory PersonnelTechnical Recorder
23 Consult With Radiation Experts Radiation Safety OfficerHealth PhysicistMedical PhysicistConference of Radiation Control Program Directors (www.crcpd.org)23. Consult with radiation experts to plan for a radiation emergency, such asThe Hospital Radiation Safety OfficerHealth PhysicistsMedical PhysicistsAnd the Conference of Radiation Control Program DirectorsCDC
24 Consult With Radiation Experts Determining/documenting presence of radioactivity, activity levels, and radiation doseCollecting samples to document contaminationAssisting in decontamination proceduresDisposing of radioactive waste24. Radiation experts will be able to assist hospitals and staff inDocumenting the presence of radionuclides, activity levels, and accident detailsCollecting samples that document contaminationAssist in decontamination proceduresCalculate and document dose calculationsDispose of radioactive waste
25 Detecting and Measuring Radiation InstrumentsLocate contamination - GM Survey Meter (Geiger counter)Measure exposure rate - Ion ChamberPersonal Dosimeters - measure doses to staffRadiation Badge - Film/TLDSelf reading dosimeter (analog & digital)25. Detecting and Measuring RadiationYou cannot see, smell, taste, feel, or hear radiation, but we have very sensitive instrumentation to detect it at very low levels. Radiation monitoring instruments detect the presence of radiation. The radiation measured is usually expressed as exposure per unit time, using various units of measure, milliroentgen per hour (mR/hr) and counts per minute (CPM). Anything with “milli” in front of it is SMALL! The most commonly used instruments to detect the presence of radiation include:Geiger- Mueller Survey Meter. The Geiger-Mueller (GM) survey meter (also known as a Geiger counter) will detect low levels of gamma and most beta radiation. The instrument typically has the capability to distinguish between gamma and most beta radiation. This instrument is used to quickly determine if a person is contaminated. GM survey meters are very sensitive and other instruments may be needed to measure higher levels.Ionization Chamber Survey Meter. This device can accurately measure radiation exposure. These meters measure from low levels (mR/hr) to higher levels (many R/hr). To find the dose an individual is receiving, multiply the dose rate by the time that they are exposed.Personal Dosimeters. These devices measure the cumulative dose of radiation received by persons wearing them. Film and TLD badges must be analyzed by the company that supplies them and so the dose received is not typically known for several days. However, self reading dosimeters allow the wearer to immediately see the total dose they have received.
26 Biodosimetry Assessment Tool 26. The Armed Forces Radiobiology Assessment Institute (AFRRI) has developed software to record radiological incidents and assess the dose based on biological response. It can be downloaded from:The records of most importance for dose assessment are:nauseavomiting (start date and time, severity)tachycardiafatigueweaknessabdominal painheadachefever (body temperature)hematologylymphocyte count (as well as monocytes, granulytes and platelets)any drug therapy usedresults of cytogeneticsArmed Forces Radiobiology Research Institute
27 Facility Preparation Plan to control contamination Instruct staff to use universal precautions and double gloveEstablish multiple receptacles for contaminated wasteProtect floor with covering if time allows27. Planning GuidelinesDetermine level of exposure once victims are medically stable. 2. Decide which victims will require decorporation measures. 3. Establish admission or referral criteria for victims.Train some members of the Medical Scene Command Team to interact with reporters and public officials seeking information about victims. Be prepared to ask the media for assistance in spreading important announcements.
28 Treatment Area Layout Separate Entrance CONTAMINATED AREA Trauma Room ED StaffRadiation Survey& ChartingCONTAMINATEDAREAContaminatedWasteTrauma RoomHOTLINESTEPOFFPADRadiationSurveyWasteBUFFERZONE28. Treatment Area LayoutThe layout for the handling of a contaminated radiation accident victim should be established to control the spread of contamination by using universal precautions.Control of individuals and materials going into the area.Control and survey of materials and personnel coming out of the area.Use appropriate steps to prevent the spread of contamination (e.g., monitor gloves and change as necessary, monitor shoes when leaving, etc.).Monitoring of the patient and the trauma room to detect, control and remove contamination.Contaminated waste water need not be contained if it will unduly complicate the treatment of the patient or it is otherwise determined to be impractical. Release of waste water can be justified in almost all situations.CleanGloves, Masks,Gowns, BootiesCLEANAREA
29 Immediate Medical Management TriageARSlocalized/ cutaneouscombined injuryInitial stabilization and treatmentPsychological effectsRecord keeping/ Dose assessment29. In this segment we will discuss:TriageARSlocalized/ cutaneouscombined injuryInitial stabilization and treatmentPsychological effectsRecord keeping/ Dose assessment
30 Protecting Staff from Contamination Universal precautionsSurvey hands and clothing with radiation meterReplace gloves or clothingthat is contaminatedKeep the work area free of contaminationKey PointsContamination is easy to detect and most of it can be removedIt is very unlikely that ED staff will receive large radiation doses from treating contaminated patients30. Protecting Staff from ContaminationHospital staff are well versed in protecting themselves and their work areas from microbiological contamination through the use of “Universal Precautions.” The same techniques can be used effectively to protect personnel and the work area from contamination by radioactive materials.One great advantage that hospital personnel have, when it comes to radioactive contamination, is the ease with which radioactive material can be detected. Most radioactive material can be detected easily and in very small quantities with the use of a simple instrument such as a GM survey meter (Geiger counter).Frequent use of the GM survey meter can alert personnel to the need to change their gloves or clothing when they become contaminated or to tell them when contamination is being spread to the work area so that cleanup and extra precautions can be implemented. Such ease of detection and control is not possible with any other type of hazardous material.Medical personnel working on the Chernobyl site after the accident received less than 1000 mrem. (Mettler and Voelz, New England Journal of Medicine, 2002; 346: )Emphasize the Key Points that most contamination is easy to detect and remove and it is very unlikely that ED staff will receive large radiation doses from treating contaminated patients.
31 Patient Management - Priorities TriageMedical triage is the highest priorityRadiation exposure and contamination are secondary considerationsDegree of decontamination dictated by number of and capacity to treat other injured patients31. Patient Management – PrioritiesMedical stabilization takes priority over decontamination.
32 Patient Management - Triage Triage based on:InjuriesSigns and symptoms - nausea, vomiting, fatigue, diarrheaHistory - Where were you when the bomb exploded or incident occurred?Contamination survey32. Patient Management - TriageResuscitation and stabilization are the primary objectives. Decontamination efforts should be secondary to patient stabilization.Severity and time of onset of nausea, vomiting, diarrhea and fatigue are noted and treated in routine clinical manner.Patient history will assist in the triage process to predict the potential extent of radiation injury.Contamination surveys are secondary to patient stabilization.
33 Psychological Casualties Terrorist acts involving toxic agents (especially radiation) are perceived as very threateningMass casualty incidents caused by nuclear terrorism will create large numbers of worried people who may not be injured or contaminated33. Psychological CasualtiesA mass casualty incident resulting from nuclear terrorism is likely to generate large numbers of frightened people who may not require decontamination or trauma care. To reassure these psychological casualties and prevent them from overwhelming health care facilities, counseling centers should be established.The hospital should plan to provide psychological support to patients and set up a center in the hospital for counseling the staff.These centers should each be staffed by physicians with radiological background, health physicists with instrumentation, and psychological counselors.
34 Psychological Casualties Provide psychological support to patients and set up a center in the hospital for staffEstablish triage (monitoring and counseling) centers to prevent psychological casualties from overwhelming health care facilitiesStaff counseling centers with physicians with a radiological background, health physicists with instrumentation and psychological counselors
35 Patient Management - Decontamination Carefully remove and bag patient’s clothing and personal belongings (typically removes 95% of contamination)Survey patient and, if practical, collect samplesHandle foreign objects with care until proven non-radioactive with survey meter35. Patient Management – DecontaminationPatient decontamination should be performed after stabilization of the patient. Removal of clothing usually occurs in the field, prior to transport to the hospital.The approach to decontamination as described in the slide will minimize contamination of and exposure to attending personnel.If internal contamination is suspected, take nasal swipes and 24 hour urine and fecal collections.Unfamiliar embedded objects in patient’s clothing or wounds may be radioactive sources. Handle with long forceps, handle only briefly, and keep distant from staff and patients until proven, with a survey meter, not to be radioactive. If radioactive objects are recovered, they should be placed in a lead container using tongs or forceps and then placed at a distance from staff and patients.
36 Patient Management - Decontamination Decontamination priorities:Decontaminate wounds first, then intact skinStart with highest levels of contaminationChange outer gloves frequently to minimize spread of contamination
37 37.Contamination – radioactive material that can be on a patient’s clothing or skin.
38 38. Contamination exterior to the body can usually be easily washed off.
39 Patient Management - Decontamination (Cont.) Protect non-contaminated wounds with waterproof dressingsContaminated wounds:Irrigate and gently scrub with surgical spongeExtend wound debridement for removal of contamination only in extreme cases and upon expert adviceAvoid overly aggressive decontaminationChange dressings frequently39. Patient Management - Decontamination (Cont.)Protection of non-contaminated wounds with waterproof dressings will minimize the potential for uptake of radioactive material.To decontaminate wounds, irrigate and gently scrub with a surgical sponge. Normal wound debridement should be performed. Excision around wounds solely to remove contamination should only be performed in extreme cases and upon the advice of radiological emergency medical experts.Many times, radioactive material will exude from wounds into gauze dressings so frequent changing of dressings may aid wound decontamination. The dressing also serves to keep the contamination in place.Remove contaminated hair if necessary, using scissors or electric clippers. To avoid cutting the skin and providing an entry for internal contamination, do not shave.Usual washing methods are effective for removal of radioactive material. Overly aggressive decontamination may abrade the skin, which would increase absorption of radioactive material, and should be avoided.Sweating can remove radioactive material from pores. Cover the area with gauze and put a glove or tape plastic over the area to promote sweating.Use a GM survey meter to monitor the effectiveness of the cleaning method.
40 Patient Management - Decontamination (Cont.) Decontaminate intact skin and hair by washing with soap & waterRemove stubborn contamination on hair by cutting with scissors or electric clippersPromote sweatingUse survey meter to monitor progress of decontamination
41 Patient Management - Decontamination (Cont.) Cease decontamination of skin and woundsWhen the area is less than twice background, orWhen there is no significant reduction between decon efforts, andBefore intact skin becomes abraded.Contaminated thermal burnsGently rinse. Washing may increase severity of injury.Additional contamination will be removed when dressings are changed.Do not delay surgery or other necessary medical procedures or exams…residual contamination can be controlled.41. Patient Management - Decontamination (Cont.)Cease decontamination of the skin and wounds when the area is less than twice the background reading on the survey meter or there is no significant reduction between washings. Under no circumstances should decontamination cause the skin to become abraded.Contaminated thermal burns can be gently rinsed while ensuring that there will be no further damage to the skin. Additional contamination will be removed with the exudate as dressings are changed.Do not delay surgery or other necessary medical procedures because of contaminated skin or wounds. Staff will be protected from becoming contaminated by using universal precautions. Sheets and dressings will keep contamination in place.
42 Patient Management - Patient Transfer Transport injured, contaminated patient into or from the ED:Clean gurney covered with sheetsLift patient onto clean gurneyWrap sheets over patientRoll gurney into ED or out of treatment room42. Patient ManagementEmergency personnel at the scene will probably remove patient’s clothing which will remove a significant amount of radioactive contamination. Contamination may persist when the patient arrives at the ED.The method shown on the slide can be used to transfer a contaminated patient into the ED without spreading contamination. The patient is transferred onto the clean gurney outside the ED, the sheets are wrapped over the patient, and the gurney is rolled into the ED and to the treatment room.When the patient is ready to be moved from the ED to other areas of the hospital, the patient can be transferred to a clean gurney. The gurney can be rolled into the potentially contaminated treatment room on a clean sheet or plastic. After the patient is transferred onto the gurney they can be transported through the hospital without concern for the spread of radioactive contamination.
43 Facility RecoveryRemove waste from the Emergency Department and triage areaSurvey facility for contaminationDecontaminate as necessaryNormal cleaning routines (mop, strip waxed floors) typically very effectivePeriodically reassess contamination levelsReplace furniture, floor tiles, etc. that cannot be adequately decontaminatedDecontamination Goal: Less than twice normal background…higher levels may be acceptable43. Facility RecoveryIf you have in-house radiation safety staff, they will supervise decontamination efforts.Environmental Services staff should remove waste from the Emergency Department and triage area and take it to a holding place until it can be surveyed for radioactive material before disposal.A radiation survey of the facility will identify any areas that need decontamination. Normal cleaning routines are typically very effective. If there is residual contamination after normal cleaning, items such as furniture and floor tiles can be replaced.The decontamination goal is for the equipment and floors to be less than twice the normal background reading. Higher levels of fixed contamination should not deter the use of emergency facilities during periods of critical need.
44 Data Management44. Keeping medical documentation is important in dealing with catastrophes, whether an accident or terrorist related.
45 Injuries Associated With Radiological Incidents Acute Radiation Syndrome (ARS)Localized radiation injuries/ cutaneous radiation syndromeInternal or external contaminationCombined radiation injuries with- Trauma- BurnsFetal effects45. In this segment we will discuss:Acute Radiation SyndromeLocalized radiation injuries/cutaneous radiation syndromeInternal or external contaminationCombined radiation injuries with- Trauma- BurnsFetal effectsCDC
46 Radiation Sickness Acute Radiation Syndrome Occurs only in patients who have received very high radiation doses (greater than approximately 100 rem or rads (1 Gy)) to most of the bodyDose ~ 15 remno symptoms, possible chromosomal aberrationsDose ~ 50 remno symptoms, minor decreases in white cells and platelets46. Radiation Sickness - Acute Radiation SyndromeRadiation sickness [acute radiation syndrome (ARS)] is an acute illness following exposure to a very large dose of ionizing radiation. It is produced if a large dose of radiation reaches enough sensitive tissue within the body. The acute radiation syndrome follows a roughly predictable course over a period of time ranging from a few hours to several weeks.For doses of approximately 15 rem, the patient should be asymptomatic, but an increased number of chromosomal aberrations may be detectable in circulating lymphocytes.For doses of approximately 50 rem, the patient should be asymptomatic, but show minor decreases in white cells and platelets.
47 Acute Radiation Syndrome (Cont.) For Doses > 100 rem Prodromal stagenausea, vomiting, diarrhea and fatiguehigher doses produce more rapid onset and greater severityLatent period (Interval)patient appears to recoverdecreases with increasing doseManifest Illness StageHematopoieticGastrointestinalCNSTime of Onset47. Acute Radiation Syndrome (Cont.)The signs and symptoms that develop in the ARS occur in four distinct phases: prodromal (initial), latent period, manifest illness stage and recovery or death.Prodromal phase. Depending on the dose of radiation, patients may experience a variety of symptoms including loss of appetite, nausea, vomiting, fatigue, and diarrhea. After extremely high radiation doses, additional symptoms such as prostration, fever, respiratory difficulties, and increased excitability may develop.Latent period. This is a transitional period in which many of the initial symptoms partially or completely resolve. It may last for a few hours or up to a few weeks depending on the radiation dose. The latent period shortens as the initial dose increases.Manifest Illness Stage. These three phases occur with increasing radiation exposure and are described on the following slides.The severity of the symptoms increases with dose, amount of the body exposed (whole body vs. partial body exposure), and the penetrating ability of the radiation. The severity is also affected by factors such as age, gender, genetics, medical conditions, etc.Severity of Effect
48 Acute Radiation Syndrome (ARS) Radiation must be of penetrating type (X-rays, gamma rays or neutrons)Most or all of body must be exposed.The dose must be from an external source.Dose must be delivered in a short time. Not fractionated.
49 The Three ARS Syndromes Hematopoetic – Between 0.7 Gy and 10 GyMortality rate is proportional to dosage.Death from hemorrhage and infectionAbsence of stem cells with leukopenia and thrombocytopenia. If they survive, anemia later.49 Absolute Lymphocyte Count: The absolute lymphocyte count is the first value to show any change after a significant radiation exposure. These changes occur rapidly and stabilize, reaching their nadir at three to five days post exposure. An exposure of 1.0 Gy will decrease lymphocyte counts to approximately 75 percent of their normal value. 2.0 Gy will cause a decrease in lymphocyte counts to approximately 50 percent of normal value, and 5.0 Gy will result in lymphocyte counts being approximately 10 percent of normal. Radiation exposures of greater than 5.0 to 6.0 Gy will result in lymphocytes being absent or minimally detected. This is exceedingly important dosimetric information, since the absolute count of lymphocytes can be used to estimate exposure. Lymphocyte levels remain depressed for four to six weeks before starting to return to normal. Six months later, normal values should be detected.Care must be taken in using the lymphocyte value to determine whether or not a patient has had radiation exposure if he has the prodromal symptoms. Influenza can result in diminished lymphocyte counts as well. Usually viral illnesses with lymphopenia will be present with atypical lymphocytes in contrast to radiation exposure. Severe depression of lymphocyte counts, however, is not a normal feature of viral illness and may be an indication of significant radiation exposure.
50 Acute Radiation Syndrome (Cont Acute Radiation Syndrome (Cont.) Hematopoietic Component - latent period from weeks to daysDose ~ 100 rem~10% exhibit nausea and vomiting within 48 hrmildly depressed blood countsDose ~ 350 rem~90% exhibit nausea/vomiting within 12 hr, 10% exhibit diarrhea within 8 hrsevere bone marrow depression~50% mortality without supportive care51. Acute Radiation Syndrome (Cont.)Radiation in very large whole body doses can cause death of the individual exposed. The clinical progression of the symptoms is dose dependent, as is the body system that exhibits the most profound effects. For very high whole body doses, the duration of time from exposure to onset of symptoms is shortened and the effects exhibited are dose dependent.
51 Acute Radiation Syndrome (Cont Acute Radiation Syndrome (Cont.) Hematopoetic Component - Latent Period From Weeks to DaysDose ~ 500 rem~50% mortality with supportive careDose ~ 1000 rem90-100% mortality despite supportive care53 Neutrophil Count: The neutrophil count is the best predictor of subsequent clinical infection. Exposures in the range of 1.0 Gy result in only a mild decrease of the neutrophil count. Exposures of up to 2.0 Gy will result in a 50 percent decrease in the neutrophil count. In contrast to the lymphocyte count, the decrease in neutrophils is gradual, reaching its nadir at four to six weeks post exposure. At greater exposures 2-6 Gy the neutrophil count may actually rise in the first several days followed by a fall. This fall may be quite precipitous, dropping to 50 percent or less of normal counts by one-week post exposure. In a patient with more significant radiation exposure, there may be a plateauing of the neutrophil counts or even a transient rise at one to two weeks. This is almost invariably followed by a further decrease in the neutrophil count. If the patient survives, recovery of neutrophils is noted between the sixth and eighth weeks post exposure. As in chemotherapeutic regimens, patients should receive appropriate 3 antibiotic coverage and isolation when the neutrophil counts become dangerously low. Susceptibility to opportunistic organisms may occur in this population as well.Platelet Count: As with the other formed blood elements, the effect on platelet count is related to the exposure level. Larger exposures will result in a decrease in the platelet count beginning within the first week or two-post exposure. Lower levels of exposure will manifest changes at four weeks.
52 Andrews Lymphocyte Nomogram Confirms suspected radiation exposureDetermines significant hematological involvementSerial CBCs every hours50. Note that all of the signs and symptoms of acute radiation exposure can be caused by stress or other illnesses.Chromosomal analysis of lymphocytes is the best determinant of radiation dose. However, this requires special analysis and usually takes 3 to 4 days. In the mean time the dose can be estimated by observing the onset of signs and symptoms and observation of the rate of lymphocyte depletion.The Andrews Lymphocyte Nomogram can be used to both confirm suspected radiation exposure as well as predict the extent of the injury.Note: The concentration of lymphocytes in circulation can be altered by trauma and can complicate the use of this as an indicator for radiation exposure.From Andrews GA, Auxier JA, Lushbaugh CC: The Importance of Dosimetry to the Medical Management of Persons Exposed to High Levels of Radiation. In Personal Dosimetry for Radiation Accidents.Vienna, International Atomic Energy Agency, 1965, pp 3- 16
53 The Three ARS Syndromes Gastrointestinal –Usually occurs with exposure to 10 and 100 Gy (1000 to 10,000 rads) –Nausea, vomiting and diarrhea.Death within two weeks with complications of infection (always have the hematopoetic syndrome as well), electrolyte imbalance, dehydration, hemorrhage.Survival uncommon.
54 Acute Radiation Syndrome (Cont.) Gastrointestinal and CNS Components Dose > 1000 rem - damage to GI systemsevere nausea, vomiting and diarrhea (within minutes)short latent period (days to hours)usually fatal in weeks to daysDose > 3,000 rem - damage to CNSvomiting, diarrhea, confusion, severe hypotension within minutescollapse of cardiovascular and CNSfatal within 24 to 72 hours55. Acute Radiation Syndrome (Cont.)Doses greater than 1000 rem will progress on a medically unalterable course.
55 The Three ARS Syndromes Cardiovascular SyndromeUsually with extremely high dosage. > 50 Gy or 5000 rads. Some symptoms possible at 20 Gy.Cerebral edema, vasculitis, meningitis with convulsions, coma and deathCardiovascular collapseDeath in 3 days or less
56 Treatment of Large External Exposures Estimating the severity of radiation injury is difficult.Signs and symptoms (N,V,D,F): Rapid onset and greater severity indicate higher doses. Can be psychosomatic.CBC with absolute lymphocyte countChromosomal analysis of lymphocytes (requires special lab)56. Treatment of Large External ExposuresThe faster the onset of signs and symptoms and the greater the severity of the drop in the lymphocytes and other blood elements will indicate higher radiation doses. (N, V, D, F) refers to nausea, vomiting, diarrhea and fatigue.The complete blood cell with absolute lymphocyte count should be taken initially and about every 6 hours thereafter (Purple top tube containing EDTA). The concentration of lymphocytes in circulation can be altered by trauma and can complicate the use of this as an indicator for radiation exposure.For chromosomal analysis, use a dark green top tube (sodium heparin tube). The light green top tube (lithium heparin with gel) is not acceptable.Treat patients symptomatically as they occur for nausea, vomiting, diarrhea, fatigue, electrolyte imbalance, and pancytopenia. Treatment should focus on prevention of infection. Antibiotics should be given to sterilize the gut and treat opportunistic infections.Hematopoietic growth factors should be given within the first 24 to 48 hours and then daily.Patients with higher exposures will require hospitalization.The telephone numbers for REAC/TS and MRAT are given in a subsequent slide.
57 Treatment of Large External Exposures Treat symptomatically. Prevention and management of infection is the primary objective.Hematopoetic growth factors, e.g., GM-CSF, G-CSF (24-48 hr)Irradiated blood productsAntibiotics/reverse isolationElectrolytesSeek the guidance of experts.Radiation Emergency Assistance Center/ Training Site (REAC/TS)Medical Radiobiology Advisory Team (MRAT)
58 Other Treatment Methods Minimize intake. Reduce and/or inhibit absorption. Block uptake. Use isotopic dilution. Promote excretion. Alter chemistry of the substance. Displace isotope from receptors. Chelate.59 Cesium137Cs (physical half-life, 30 years; biological half-life, 109 days) is the dominant radioisotope in aged fission products.Distributes in body fluids similarly to potassium.The most effective means for removing radioactive cesium is the oral administration of ferric ferrocyanate, commonly called Prussian Blue.One gram orally three times daily x 3 weeks reduces the biological half-life to about 1/3 of the normal value.Tritium - 3HFollows pathway of water in the body.Penetrates skin, lungs, and GI tract, either as tritiated water (HTO) or in the gaseous form.Single exposures are treated by forcing fluids.This has the dual value of diluting the tritium and increasing excretion.Biological half-life is 10 days.Forcing fluids to tolerance (3-4 L/d) will reduce the biological half-life to 1/3 to 1/2 of the normal value.Chelating Agents - DTPATrisodium calcium diethylenetriaminepentaacetate (Ca-DTPA).Chelating agent for transuranic elements.Ca-DTPA is approximately 10 times more effective than Zn-DTPA for initial chelation of transuranics. It is the treatment of choice for initial patient management. Must be given as soon as possible after accident.Repeated dosing of Ca-DTPA can deplete the body of zinc and manganese.Dosage of Ca-DTPA and Zn-DTPA is 1 gm intravenously or inhalation in a nebulizer (1:1 dilution with water or saline).Very safe drug with no significant adverse reactions noted during 25 years of usage.Initially: 1 gm Ca-DTPA; repeat 1 gm Zn-DTPA daily up to five days if bioassay results indicate need for additional chelation.Ca-DTPA: Pregnancy category D.Zn-DTPA: Pregnancy category C.DTPA + DFOA may be a better combination.DTPA - Relative ContraindicationsPregnancy: Use first dose as Zn-DTPA instead of Ca-DTPA.Diabetic on Insulin: Use Zn-DTPA and monitor glucose levels.Depressed myelopoietic function: Use clinical judgment.Impaired renal function: Use clinical judgment.Children: Limited data available. Additional Chelating agentsDimercaprol (BAL) forms stable chelates with mercury, lead, arsenic, gold, bismuth, chromium, and nickel. It may therefore be used for the treatment of internal contamination with radioisotopes of these elements.Deferoxamine (DFOA) has been effective in treatment of iron storage disease; may be used for chelation of 59Fe.Penicillamine (PCA) chelates with copper, iron, mercury, lead, gold. It is superior to BAL and Ca-EDTA for removal of copper (Wilson’s Disease).
59 Treatment of Internal Contamination Radionuclide-specificMost effective when administered earlyMay need to act on preliminary informationNCRP Report No. 65, Management of Persons Accidentally Contaminated with RadionuclidesRadionuclide Treatment RouteCesium-137 Prussian blue OralIodine-125/131 Potassium iodide OralStrontium-90 Aluminum phosphate OralAmericium-241/ Ca- and Zn-DTPA IV infusion,Plutonium-239/ nebulizerCobalt-6058. Treatment of Internal ContaminationDeposition of radioactive materials in the body (i.e., internal contamination), is a time-dependent, physiological phenomenon related to both the physical and chemical natures of the contaminant.The rate of radionuclide incorporation into organs can be quite rapid. Thus, time can be critical and treatment (decorporation) urgent.Several methods of preventing incorporation (e.g., catharsis, gastric lavage) might be applicable and can be prescribed by a physician.Some of the medications or preparations used in decorporation might not be available locally and should be stocked.NCRP Report No. 65, Management of Persons Accidentally Contaminated with Radionuclides, addresses the strategies to limit the exposure from internal contamination by radioactive materials. Radiation Protection Dosimetry published a Guidebook for the Treatment of Accidental Internal Radionuclide Contamination of Workers (1992) that provides additional information on patient management.In January 2003, the Food and Drug Administration (FDA) determined that Prussian blue had been shown to be safe and effective in treating people exposed to radioactive elements such as Cesium-137.In August 2004, the FDA determined that two drugs, pentetate calcium trisodium injection (Ca-DTPA) and pentetate zinc trisodium injection (Zn-DTPA), are safe and effective for treating internal contamination with plutonium, americium, or curium. The drugs increase the rate of elimination of these radioactive materials from the body.
60 Blocking Radioactive Iodine The dominant initial internal contaminant after a reactor accident, nuclear weapons test, or any incident involving fresh fission products is likely to be 131I.Block thyroid if radioactive iodine is a factor or if you are unsure. Give potassium Iodide 130 mg immediately to an adult then continue for 7 days.60 Treatment Methods Minimize intake. Reduce and/or inhibit absorption. Block uptake. Use isotopic dilution. Promote excretion. Alter chemistry of the substance. Displace isotope from receptors. Chelate.Tritium - 3HFollows pathway of water in the body.Penetrates skin, lungs, and GI tract, either as tritiated water (HTO) or in the gaseous form.Single exposures are treated by forcing fluids.This has the dual value of diluting the tritium and increasing excretion.Biological half-life is 10 days.Forcing fluids to tolerance (3-4 L/d) will reduce the biological half-life to 1/3 to 1/2 of the normal value.UraniumSolubility classes: 1. UF6 (uranium hexafluoride): Class D (days). 2. UO2(NO3)2 - Uranyl nitrate: Class D. 3. UO2 - Uranium dioxide: Class W,Y (weeks, years). 4. UO2 - High-fired uranium dioxide: Class Y.Inhalation is usual occupational exposure.Overall biological half-life is 15 days.85% of retained uranium resides in bone.Kidney toxicity is the basis of occupational exposure limits.In acidic urine, uranyl ion complex with tubule surface proteins.Some of the bound UO22+ is retained in the kidney.Kidney is the first organ to show chemical damage in the form of nephritis and proteinuria.Oral doses or infusions of sodium bicarbonate are the treatment of choice and should be dosed to keep the urine alkaline by frequent pH measurements.IodineThe dominant initial internal contaminant after a reactor accident, nuclear weapons test, or any incident involving fresh fission products is likely to be 131I.Thyroid is generally blocked by dilution; 130 mg KI tablet immediately and one tablet daily x 7-14 days.5 or 6 drops of SSKI (Saturated Solution of Potassium Iodide (1 g/ml)) is another convenient way to administer stable iodide.Potassium perchlorate (200 mg) may be used in patients with iodine sensitivity.Dose of Stable Iodine to Exposed GroupsConsider a basic tablet giving 50 mg of I.Adults: two tablets.Children and adolescents: one tablet.Infants: 1/2 tablet.Neonates: 1/4-1/2 tablet crushed up in jam or a drink.Timing: immediate. However, in a situation with continuing exposure, stable I may be 50% effective even 5 hours after exposure to radioiodine.
61 Special Considerations High radiation dose and trauma interact synergistically to increase mortalityClose wounds on patients with doses > 100 remWound, burn care and surgery should be done in the first 48 hours or delayed for 2 to 3 months (> 100 rem)Hours~3 MonthsEmergencySurgeryHematopoietic RecoveryNo SurgeryAfter adequatehematopoietic recoveryPermitted61 Special ConsiderationsPatients who have suffered trauma (from an explosive or burn) combined with an acute high level exposure to penetrating radiation will have increased morbidity as compared to patients who have received the same dose of radiation without trauma.If a patient has received an acute dose greater than 100 rad, efforts must be made to close wounds, cover burns, reduce fractures, and perform surgical stabilizing and definitive treatments within the first 48 hours after injury.After 48 hours, surgical interventions should be delayed until hematopoietic recovery has occurred.
62 Cutaneous Radiation Syndrome May occur as part of the ARSMay occur from beta rays or X-rays without ARSMay be due to contamination of patients skin or clothing from radioactive particles.
63 Cutaneous Radiation Syndrome InflammationErythema usually with itching at firstDry desquamation, epilation,Moist desquamationUlceration, blisters,Basal cell layer damaged, sebaceous and sweat glands destroyed. Hyperpigmentation laterDelayed onset of about days to weeks.
64 Biological Effects of Ionizing Radiation Deterministic effects:occur when the dose is above a given threshold (characteristic for the given effect);severity increases with the dose;many cells must die or have their function alteredexamples: erythema, fibrosis, marrow depletion, cataract.Stochastic (probabilistic):have no known threshold;probability of occurrence increases with dose;may result from alteration in only one or a few cellsexamples: carcinogenic - various neoplasms,genetic - various hereditary disorders.
66 Localized Radiation Effects - Organ System Threshold Effects Skin - No visible injuries < 100 remMain erythema, epilation >500 remMoist desquamation >1,800 remUlceration/Necrosis >2,400 remCataractsAcute exposure >200 remChronic exposure >600 remPermanent SterilityFemale >250 remMale >350 rem66. Localized Radiation Effects - Organ System Threshold EffectsPartial body radiation can cause localized effects if the dose is sufficiently high.Radiation doses to the skin can cause reddening of the skin, blistering, and ulceration. Higher doses are required for blistering and ulceration than for skin reddening. This photo is from a patient who had 3 angioplasty procedures under fluoroscopic guidance. It shows deep necrosis of the skin 22 months after an exposure of ~2000 rem.A patient may present with injuries from exposure to a lost or stolen high-activity commercial radiation source. The patient may not be aware that he or she was exposed. Such a patient may have localized burn-like skin injuries without a history of heat exposure. Epilation, a tendency to bleed, nausea and vomiting and/or other symptoms of the acute radiation syndrome may be present.Cataracts have developed in some early radiation workers who received high doses to the lens of their eyes.Loss of fertility has occurred in both males and females whose gonads were exposed to very high doses of radiation.
67 Time of Onset of Clinical Signs of Skin Injury Depending on the Dose Received Symptoms Dose range Time of onset(Gy) (day)ErythemaEpilation >Dry desquamationMoist desquamationBlister formationUlceration >Necrosis > >21Ref.: IAEA-WHO: Diagnosis and Treatment of Radiation Injuries.IAEA Safety Reports Series, No. 2, Vienna, 1998
68 Longer Term Considerations Following Radiation Injury NeutropeniaPain managementNecrosisPlastic/reconstructive surgeryPsychological effects (PTSD)CounselingDose assessmentsPossible increased risk of cancerConsult Radiation Emergency Assistance Center/ Training Site (REAC/TS) for advice for further treatment:68.After immediate treatment of radiation injury, an often long and painful process of healing will ensue. The most important concerns are:NeutropeniaPain ManagementNecrosisPlastic/reconstructive surgeryPsychological effects (PTSD)CounselingDose AssessmentsPossible increased risk of cancerTurn to Radiation Emergency Assistance Center/ Training Site (REAC/TS) for advice for further treatment:
69 Chronic Health Effects From Radiation Radiation is a weak carcinogen at low dosesNo unique effects (type, latency, pathology)Natural incidence of cancer ~ 40%; mortality ~ 25%Risk of fatal cancer is estimated as ~ 4% per 100 remA dose of 5 rem increases the risk of fatal cancer by ~ 0.2%A dose of 25 rem increases the risk of fatal cancer by ~ 1%69. Chronic Health Effects from RadiationHigh radiation doses have been linked to a modest increase in the incidence of cancer in exposed populations, such as the atomic bomb survivors. At low doses, below about 20 rem, the potential for cancer causation is uncertain and generally believed to be quite small.The natural incidence of cancer in the population of the United States, over a lifetime, is estimated to be approximately 40% and the risk of mortality is approximately 25%. [Reference - SEER (Surveillance, Epidemiology and End Results) Program of the National Cancer Institute]Risk of fatal cancer from ICRP Publication 60.There are several sets of recommendations for acceptable doses to emergency workers performing life saving actions. While these doses are 5 to 10 times higher than annual occupational dose limits, it represents a modest increase in cancer risk during life saving measures.EPA / NRC remNCRP / ICRP Approach or exceed 50 rem(EPA, Manual of Protective Action Guides and Protective Actions for Nuclear Incidents, 1992)(NCRP Report 116, Limitation on Exposure to Ionizing Radiation, 1993)(IRCP Report 60, 1990 Recommendations of the International Commission on Radiological Protection, 1991)
70 Stochastic Effects of Radiation Exposure Frequency is proportional to doseNo threshold doseNo method for identification of the appearance of this effect of ionizing radiation in individualsIncrease in occurrence of stochastic effect can be proved with epidemiological method only
72 Cancer Deaths Attributable to A-bombs In 86,572 survivors of Hiroshima and Nagasaki A-bombing 7,827 persons died of cancer in :Observed Expected Excess (%)All tumors (4.4)Leukaemia (35.0)All cancers (5.4)Ref: Pierce et al, Rad.Res. 146: 1-27, 1996
75 Teratogenic Effects of Radiation Mental retardationHighest risk during major neuronal migration, on 8-15 weeks. Incidence increases with dose. At 1 Gy fetal dose 75% experience severe retardationAt weeks, fetus shows no increase in mental retardation at doses < 0.5 GyIQ - Risk factor associated with diminution of IQ is points at 1 Gy to fetus on 8-15 weeks.MicrocephalyObserved in 30 children of ~1000 exposed in Hiroshima and Nagasaki pregnant womenThe effect <0.3 Gy is not significantly different of control
76 Fetal Irradiation No Significant Risk of Adverse Developmental Effects Below 10 Rem Period ofDevelopmentWeeks AfterFertilizationEffects<22-77-40AllPre-implantationOrganogenesisFetalLittle chance of malformation.Most probable effect, ifany, is death of embryo.Reduced lethal effects.Teratogenic effects.Growth retardation.Impaired mental ability.Growth retardation withhigher doses.Increased childhoodcancer risk. (~ 0.6% per 10 rem)76. Fetal IrradiationTermination of pregnancy is NOT justified based upon radiation risks for fetal doses less than 10 rem.Excess childhood cancer risk is ~0.06% per rem. Normal childhood cancer incidence is 0.075%.Fetal doses greater than 50 rem can cause significant fetal damage, the magnitude and type of which is a function of dose and stage of pregnancy.For fetal doses between 10 and 50 rem, decisions regarding termination of pregnancy should be made based upon individual circumstances.
77 Key Points Medical stabilization is the highest priority Train/drill to ensure competence and confidencePre-plan to ensure adequate supplies and survey instruments are availableUniversal precautions and decontaminating patients minimizes exposure and contamination riskEarly symptoms and their intensity are an indication of the severity of the radiation injuryThe first 24 hours are the worst; then you will likely have many additional resources77. Key PointsEmphasize that medical stabilization of the patients is the highest priority. Patients will not succumb immediately from radiation injury. Radiation exposure and contamination are not immediately life threatening nor are contamination levels or exposure levels of significant hazard to personnel.Training and drills are the best preparation to ensure competence and confidence by the the ED and other staff identified in the Emergency Plan.Pre-plan to ensure that adequate supplies and survey instruments are available. Identify non-ED staff that can assist. Staff from Nuclear Medicine, Radiation Oncology and Radiation Safety have expertise in radiation protection practices and the use of survey meters.The staff can protect themselves from radioactive contamination by using universal precautions while treating these patients. Treating these patients is not an immediate hazard to ED staff health and the long term risks from the radiation exposure are small.Early symptoms and their intensity in patients are an indication of the severity of the radiation injury.The first 24 hours are the worst. Then you will likely have many additional resources from state and federal agencies.
79 The Three Basic Ways to Reduce Radiation Exposure TIME Decrease the amount of time you spend near the source of radiation. DISTANCE Increase your distance from a radiation source. SHIELDING Increase the shielding between you and the radiation source. Shielding is anything that creates a barrier between people and the radiation source. Depending on the type of radiation, the shielding can range from something as thin as a plate of window glass or as thick as several feet of concrete. Being inside a building or a vehicle can provide shielding from some kinds of radiation.
80 Personally, What You Should Do! Radiological Attack Avoid inhaling dust as it could be radioactive.If an explosion occurs outdoors and you are informed that radiation is involved, if you are outdoors, cover nose and mouth and seek indoor shelter as soon as possible.If you inside an undamaged building, stay there. Close windows and doors and shut down ventilation system. Exit when told that it is safe after testing.
81 Personally, What You Should Do! Radiological Attack If an explosion occurs inside your building, cover nose and mouth and evacuate as soon as possible.Decontaminate by removing clothing and showering.Relocate outside the contaminate zone.Obey public officials.This is the scenario of a dirty bomb.
82 Personally, What You Should Do! Actual Nuclear Attack Move out of the path of a nuclear fallout cloud as quickly as possible (10 minutes or less) if you are in the blast zone and can do so. Find medical help ASAP.
83 Reproduced with permission Prepared by the Radiological Emergency Medical Preparedness & Management Subcommittee of the National Health Physics Society Ad Hoc Committee on Homeland Security.Jerrold T. Bushberg, PhD, Chair Kenneth L. Miller, MSMarcia Hartman, MSRobert Derlet, MD Victoria Ritter, RN, MBAEdwin M. Leidholdt, Jr., PhDConsultants Fred A. Mettler, Jr., MDNiel Wald, MDWilliam E. Dickerson, MDAppreciation to Linda Kroger, MS who assisted in this effort.
84 Other ResourcesAdditional slides by permission Istvan Turai MD PhD, International Atomic Energy CommissionCDC Video “Medical Response to Nuclear and Radiological Terrorism”REACT/REAC/TS (Oak Ridge Radiation Emergency Assistance Center/Training Site) DOE/OROC (865)
85 Always Contact Local Public Health Department Tarrant County Public Health 1101 S. Main Street Fort Worth, Texas 76104Dallas County Department of Health & Human Services 2377 N. Stemmons Freeway Dallas, Texas