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CHAPTER 10:  Radiation Injuries      47 Public health agencies should also provide a clear and concise case definition for the particular agent in question. A case definition imparts definitive clinical and diagnostic criteria for an individual patient. Within the case definition, criteria should be supplied that define “presumptive” or “suspect” cases for patients awaiting confirmatory testing. This kind of tool is simple and allows practitioners to offi cially designate victims as “confirmed” or “presumptive/suspected” for the target illness. Similarly delineated “exposure” categories are helpful in providing criteria for stratifying risk by designating “confirmed” or “presumptive” (suspected) exposure. Another specific bioterrorism-related challenge to ED operations occurs when patients present after having been exposed to an uniden tified substance (e.g., white powder), with circumstances that raise suspicion for terrorism (e.g., threatening letter, high-profile location, a “very important person”). The source substance may not have been properly evaluated or secured, and any recommended treatment necessarily will involve coordination with outside agencies, especially public health and law enforcement. If no environmental or agent testing was performed, one may attempt to obtain confirmatory studies through the local public health authorities if the substance remains available. Otherwise, the difficult task of stratifying patient exposure risk is nec essary, using arguably nonspecific factors such as patient demographics and the specific characteristics of the incident (e.g., white powder found in a local business vs. a high-level federal official’s office). Consult the public health authorities with jurisdiction over the involved commu nities early in the process, ideally by using a preplanned notification process and decision support tools. When testing has been performed by others, request specific information on the testing methodology. For example, anthrax environmental testing may be performed with a wide range of procedures, including immune-based assays, assays based on polymerase chain reaction, and confirmatory culture testing. 27 Older immune-based assays caused numerous instances of false-positive environmental tests, which were subsequently reported in the media and created serious public concern during and after the 2001 anthrax incident. Clearer understanding of the sensitivity and specificity of these tests could have assisted in interpretation and representation of results.  INTEGRATION WITH OTHER RESPONSE ASSETS: MUTUAL AID AND THE STRATEGIC NATIONAL STOCKPILE Just-in-time inventory practices may limit the amount of vaccine, anti biotics, other pharmaceuticals, and supplies available. Requests for assistance or for resources not available within an individual hospital should be coordinated through the hospital administration to other hospitals through mutual aid mechanisms, the local department of health, and the local emergency management agency. From there, requests may be transmitted to the regional, state, or federal levels. Without this coordination, supply management during a bioterror ism event will become an issue. For example, vendors for emergency back-up supplies and equipment are commonly shared by multiple institutions, each counting the vendor’s back-up cache as their own.

be transmitted to the regional, state, or federal levels. Without this coordination, supply management during a bioterror ism event will become an issue. For example, vendors for emergency back-up supplies and equipment are commonly shared by multiple institutions, each counting the vendor’s back-up cache as their own. Having a community-wide mutual aid system between all the hospitals promotes appropriate sharing of critical supplies, equipment, and staff during an emergency. If prescriptions are being written for antibiotics, the local pharmacies’ on-hand supply should be considered. Writing short-course prescriptions with procedures to provide completion of the medication regimen may be indicated until adequate supplies are available, but this strategy should be implemented on a region-wide basis to not place an individual practitioner’s patients at increased risk. Integration of Strategic National Stockpile supplies into a medical community has specific requirements that are available for review through the Centers for Disease Control and Prevention and requires specific planning by the community emergency management and public health agencies. REFERENCES The complete reference list is available online at www.TintinalliEM.com. Radiation Injuries Annette M. Lopez Jennifer A. Stephani INTRODUCTION Radiation exposures encountered in the ED setting may either be acci dental or intentional. Accidental exposures can occur during transport, storage, or working with radioactive materials or with errors in dosing radiotherapy. Most civilian incidents involve industrial exposures from sealed radiation sources. Historically, there have been multiple events that have resulted in radiation injuries. In August 1945, nuclear weapons were detonated over Hiroshima and Nagasaki, resulting in nearly 200,000 acute deaths and untold numbers of resulting injuries. The 2011 Fukushima Daiichi nuclear plant disaster involved about 1000 disaster-related deaths, although no deaths have yet been attributed to radiation injuries. 2 The largest reported civilian accidental exposure took place in 1987 after a radiosource was left at an abandoned radiotherapy institute in Goiania, Brazil. Due to the source’s ability to glow in the dark, its contents were widely distributed, resulting in 112,000 individuals requiring evalua tion, 249 contaminations, 20 individuals requiring hospital admissions, and four deaths. 3,4 In 2006, Alexander Litvenko, a defected former KGB agent, suffered a protracted gastrointestinal illness associated with leu kopenia after meeting with former colleagues. His death was ruled a murder after elevated levels of polonium-210 were identified. Investigations into his murder revealed multiple rehearsals throughout England, leading to the contamination of multiple sites with potential exposures to 1693 local and international individuals. 5-7 A potential intentional exposure involves the use of radiologic dis persal devices, or “dirty bombs, ” that combine radioactive materials with conventional explosives. They are meant to cause injuries to those nearby, while generating massive panic and hysteria, overwhelming the local resources, damaging the local economy, and causing prolonged clean-up efforts. FUNDAMENTALS OF RADIATION PHYSICS Radiation energy includes the entire electromagnetic spectrum. Ionizing radiation contains enough energy to remove electrons from an atom, generating charged particles. Sources of ionizing radiation include alpha particles, beta particles, neutrons, and energy waves, including radio graphs and gamma rays. 8 Table 10-1 reviews the types of radiation.  ALPHA PARTICLES Alpha particles are relatively large in size (two protons and two neutrons), resulting in a limited travel potential and thus preventing penetration of the skin.

a particles, beta particles, neutrons, and energy waves, including radio graphs and gamma rays. 8 Table 10-1 reviews the types of radiation.  ALPHA PARTICLES Alpha particles are relatively large in size (two protons and two neutrons), resulting in a limited travel potential and thus preventing penetration of the skin. Shielding is easily accomplished with a piece of paper. Pathology only develops through inhalation, ingestion, or absorption. Its detection can be challenging since a special Geiger counter attachment is needed.  BETA PARTICLES Beta particles are much smaller (a single electron); thus, they have greater ability to travel and penetrate tissues. It is a significant hazard if internally deposited. It is a common exposure since most radioisotopes decay by beta radiation followed by gamma emission.  POSITRONS Positrons are positively charged beta particles emitted from atomic nuclei. They are the antiparticles to an electron, and interactions with electrons lead to the generation of highly energetic photons requiring shielding with lead, steel, or concrete. Positron sources are commonly used in medicine. CHAPTER Tintinalli_Sec02_p0019-0052.indd 47 7/30/19 4:59 PM

rticles emitted from atomic nuclei. They are the antiparticles to an electron, and interactions with electrons lead to the generation of highly energetic photons requiring shielding with lead, steel, or concrete. Positron sources are commonly used in medicine. CHAPTER Tintinalli_Sec02_p0019-0052.indd 47 7/30/19 4:59 PM 48 SECTION 2: Disaster Management TABLE 10-1 Types of Radiation Type (Symbol) Charge Penetration Shield Hazard Source Alpha +2 Few centimeters in air Paper, keratin layer of skin Internal contamination only; requires special detection devices Heavy radioisotopes (e.g., plutonium, uranium, radon) Beta –1 ~8 mm into skin Clothing External (skin) and internal contamination Most radioisotopes decay by beta followed by gamma emission Positron +1 ~8 mm into skin Lead, steel, or concrete Interacts with electrons and releases photons of energy Medical tracers Neutron 0 Variable Material with high hydrogen content Whole-body irradiation Nuclear power plants, particle accelerators, weapons assembly plants Gamma and radiograph 0 Several centimeters in tissue Concrete, lead Whole-body irradiation Most radioisotopes decay by beta followed by gamma emission TABLE 10-2 Radiation Units of Measure Description Conventional Units SI Unit Conversion Activity Curie Becquerel 1 Bq = ~2.7 × 1011 Ci Units of activity describe the amount of radioactivity present. 1 Ci = ~3.7 × 1010 Bq Exposure Roentgen Coulomb per kilogram 1 R = 2.58 × 104 cP/kg Units of exposure measure the amount of radiographs or gamma radiation that produces a given number of ionizations in air. Absorbed dose rad Gray 1 rad = 0.01 Gy Units of absorbed dose can be applied to any type of radiation and reflect the energy imparted to matter. 1 Gy = 100 rad Dose equivalent Roentgen equivalents man Sievert 1 rem = 0.01 Sv Units that provide a common scale of measure for the different types of radiation. 1 Sv = 100 rem Abbreviation: SI = International System of Units. TABLE 10-3 Radiation Monitoring Equipment Equipment Type Device Common Type of Measurement Units Commonly Recorded Dosimeter Thermoluminescent dosimeter or film badge Cumulative dose of beta, radiograph, and gamma Roentgen equivalents man or sieverts Dosimeter Pocket dosimeter Cumulative exposure to radiogrpah and gamma Milliroentgen Survey meter Geiger-Müller tube Low exposure rates of radiograph, gamma, and beta* Counts per minute† Survey meter Ion chamber Higher exposure rates of radiograph and gamma Milliroentgen per hour *With special instrument probes, alpha radiation can also be detected. †2500 counts per minute equal approximately 1 mR/h.  NEUTRONS Neutrons are uncharged particles that are able to generate radiation by altering the atomic nuclear proton-to-electron ratio. These particles are capable of traveling large distances; thus, shielding requires the use of helium, water, or paraffin. Exposures are rare and usually limited to nuclear fallout, research, industry, and weapons manufacturing.  GAMMA RAYS AND RADIOGRAPHS Gamma rays and radiographs are able to travel meters in the air and can penetrate centimeters into human tissue. Shielding materials must be very dense (concrete or lead). Individuals exposed to high doses are at risk of developing acute radiation syndrome. BIOLOGIC EFFECTS OF IONIZING RADIATION Ionizing radiation leads to cellular effects at various levels of exposure. At high doses, ionizing radiation causes cell death, whereas at lower doses, it interrupts cellular reproduction through inhibition of mitosis, resulting in cellular injury with delayed onset of effects. 9 Rapidly dividing cells with short life spans are the cells most vulnerable to radiation injury, because they are quickly depleted and new cells are unable to replete the population.

er doses, it interrupts cellular reproduction through inhibition of mitosis, resulting in cellular injury with delayed onset of effects. 9 Rapidly dividing cells with short life spans are the cells most vulnerable to radiation injury, because they are quickly depleted and new cells are unable to replete the population.  MEASURING RADIATION There are many ways in which radiation can be measured: dose given, exposure received, absorbed dose, or activity generated. Each form of measurement generates its own unit, generating confusion between the units (Table 10-2).  RADIATION MONITORING EQUIPMENT Commonly used equipment includes dosimeters and survey meters (Table 10-3). During radiation emergencies, both of these devices should be used. Staff should wear dosimeters due to their small size and ability to measure and record cumulative exposure doses. In contrast, rate meters record the amount of radiation in an area over a particular time course and are suited to monitor environmental contamination.  ALLOWED ANNUAL DOSE OF RADIATION Radiation exposures are an unavoidable hazard of living on our planet. The background radiation dose of individuals living in the United States is approximately 6.2 mSv (620 mrem). 10 The U.S. Nuclear Regulatory Commission as well as other international regulatory agencies have accepted an annual radiation dose limit for the general public at 1 mSv per year (100 mrem) over natural background radiation. See Table 10-4 for selected approximate levels of radiation exposure.  LETHAL DOSE OF RADIATION The LD50/60 from exposure to ionizing radiation is defined as the dose of penetrating ionizing radiation that will result in the deaths (lethal dose) Tintinalli_Sec02_p0019-0052.indd 48 7/30/19 4:59 PM

background radiation. See Table 10-4 for selected approximate levels of radiation exposure.  LETHAL DOSE OF RADIATION The LD50/60 from exposure to ionizing radiation is defined as the dose of penetrating ionizing radiation that will result in the deaths (lethal dose) Tintinalli_Sec02_p0019-0052.indd 48 7/30/19 4:59 PM CHAPTER 10:  Radiation Injuries      49 of 50% of the exposed population within 60 days without medical treatment. The most commonly cited human value is an LD 50/60 of approximately 3.5 to 4.5 Gy (350 to 450 rad). 8 The use of supportive medical therapy increases the value to 4.8 to 5.4 Gy (480 to 540 rad). During mass exposures, where resources may be limited, the LD 50/60 falls to approximately 3.4 Gy (340 rad). Stem cell transplantation and the use of hematopoietic growth factors theoretically increases the LD 50/60 to 11 Gy (1100 rad).11 CLINICAL EFFECTS OF RADIATION  LOCAL RADIATION INJURY Most radiation accidents are due to local radiation injury from partialbody exposure. This irradiation rarely causes systemic manifestations; rather, a dose-dependent cutaneous involvement is seen. Typically, these injuries tend to be asymptomatic in the first week, although, there may be transient erythema (6 Gy), hyperesthesia, and itching. Within the second week, erythema progresses to hair loss (3 Gy). Skin tenderness, swelling, and pruritus occur in the third week after exposure. Within the fourth week, the wound will develop dry (10 to 15 Gy) or wet (20 to 50 Gy) desquamation and radionecrosis with ulceration (>50 Gy). These skin findings may be indistinguishable from thermal burns, except for the delayed onset of prolonged and severe pain. In exposures less than 50 Gy (5000 rad), these injuries develop over a longer time period than thermal burns. At doses greater than 50 Gy, the onset of pain will occur immediately, and wounds will be indistinguishable from thermal burns. Surgical intervention, such as resection and grafting, may be required.  ACUTE RADIATION SYNDROME Acute radiation syndrome occurs after a significant exposure (whole-body gamma dose exceeds 2 Gy) within a 24-hour time period (Table 10-5). It can also occur in the setting of neutron source exposure or internal contamination with alpha and/or beta radiation. Acute radiation syndrome develops in four distinct phases: prodrome, latent phase, manifest-illness, and recovery. The prodrome involves a transient autonomic nervous system response to the exposure characterized by nausea, vomiting, anorexia, and diarrhea accompanied by hypotension, pyrexia, diaphoresis, ceph algia, and fatigue. It is directly related to the dose received: high doses cause acute and severe symptoms, whereas lower doses lead to milder symptoms and prolonged onset. The latent phase follows and involves a symptom-free interval the duration of which depends on the received dose, with larger doses resulting in a shorter duration. Doses less than 4 Gy are associated with a period that may last 1 to 3 weeks, whereas with doses greater than 15 Gy, this phase may last only a few hours. The manifest-illness phase is subdivided into three dose-dependent syndromes that are hallmarked by the affected organ system. They are not independent of one another and may overlap in clinical manifestations. Hematopoietic Syndrome With doses greater than 2 Gy, the hema topoietic system is the first affected organ system. The prodrome of this syndrome occurs within hours to a few days from the exposure, resolves within 48 hours, and is followed by a latent phase lasting 1 to 3 weeks. Radiation damages the bone marrow stem cells, resulting in destruction of the circulating hematopoietic cells ( Figure 10-1). Lymphocytes are preferentially destroyed.

of this syndrome occurs within hours to a few days from the exposure, resolves within 48 hours, and is followed by a latent phase lasting 1 to 3 weeks. Radiation damages the bone marrow stem cells, resulting in destruction of the circulating hematopoietic cells ( Figure 10-1). Lymphocytes are preferentially destroyed. The peripheral lymphocyte count is the most readily available marker to grade the extent of the injury. Other cells lines are also affected. Since granulocytes and platelets are markers of inflammation, their counts initially rise following exposure, but reach a nadir within 30 days of the injury. Morbidity and mortality are dependent on the resulting pancytopenia, immunosuppression, and hemorrhage. Aggressive medical management with blood products and growth factors may increase survival. GI Syndrome Doses greater than 6 Gy (>600 rad) are characterized by nausea, vomiting, and diarrhea within hours of exposure. A short latent phase lasting up to 1 week follows. A recrudescence of severe nausea, vomiting, diarrhea, and abdominal pain indicates the manifest illness phase that occurs after the failure to replenish the lost intestinal mucosa. Massive fluid and electrolyte shifts occur, as well as the translocation of enteric flora into the bloodstream, leading to the development of fulminant enterocolitis. Neurovascular Syndrome This occurs when doses exceed 12 Gy. It involves immediate persistent and intractable hypotension, prostra tion, nausea, vomiting, and explosive bloody diarrhea. CNS symptoms develop within hours and include seizures, lethargy, disorientation, ataxia, and tremors. The lymphocyte count quickly falls to near-zero levels, and death from circulatory collapse ensues within 24 to 48 hours. If reached, the final stage of acute radiation syndrome is recovery. EMERGENCY RESPONSE PLANNING Emergency response plans should involve multiple community-wide organizations, including hospitals, EDs, and public safety, public health, and emergency management officials. Every EMS system should have a prehospital plan for the evacuation of victims from a radiation disaster. Every hospital is required by The Joint Commission to have a written protocol detailing instructions for receiving and treating radiation vic tims. Hospitals should stage regular disaster drills and train personnel in decontamination procedures, use of personal protective equipment, and radiologic monitoring. Planning templates exist to assist hospitals in developing appropriate radiation emergency response plans. 13,14  PREHOSPITAL EMERGENCY MEDICAL MANAGEMENT Emergency responders should rapidly establish incident command in a situation involving radioactive materials. Personal protective equipment and respiratory protection should be used as the situation dictates. Care and transportation of seriously injured victims should not be delayed, TABLE 10-4 Selected Approximate Levels of Radiation Exposure Natural background radiation 620 mrem/y (U.S. average) Chest radiograph (effective dose) 10 mrem Abdominal radiograph 120 mrem Lumbar spine radiograph 70 mrem CT head 200 mrem CT chest 700 mrem CT abdomen or pelvis 1000 mrem Jet travel 1 mrem per 1000 miles traveled Annual radiation dose limit (public) 100 mrem/y* Occupational exposure limit 5000 mrem/y Lethal dose in 50% of exposed subjects within 60 d (3.5–4.5 Gy) 350,000–450,000 mrem (350–450 rad†) *Over natural background radiation. †1 rem (dose equivalent) = 1 rad (absorbed dose or exposure).

el 1 mrem per 1000 miles traveled Annual radiation dose limit (public) 100 mrem/y* Occupational exposure limit 5000 mrem/y Lethal dose in 50% of exposed subjects within 60 d (3.5–4.5 Gy) 350,000–450,000 mrem (350–450 rad†) *Over natural background radiation. †1 rem (dose equivalent) = 1 rad (absorbed dose or exposure). TABLE 10-5 Acute Radiation Syndrome Approximate Dose Onset of Prodrome Duration of Latent Phase Manifest Illness >2 Gy (200 rad) Within 2 d 1–3 wk Hematopoietic syndrome with pancytopenia, infection, and hemorrhage; survival possible >6 Gy (600 rad) Within hours <1 wk GI syndrome with dehydration, electrolyte abnormalities, GI bleeding, and fulminant enterocolitis; death likely >20–30 Gy (2000–3000 rad) Within minutes None Cardiovascular/CNS syndrome with refractory hypotension and circulatory collapse; fatal within 24–72 h Tintinalli_Sec02_p0019-0052.indd 49 7/30/19 4:59 PM

s <1 wk GI syndrome with dehydration, electrolyte abnormalities, GI bleeding, and fulminant enterocolitis; death likely >20–30 Gy (2000–3000 rad) Within minutes None Cardiovascular/CNS syndrome with refractory hypotension and circulatory collapse; fatal within 24–72 h Tintinalli_Sec02_p0019-0052.indd 49 7/30/19 4:59 PM 50 SECTION 2: Disaster Management even if the patient is contaminated. In medically stable patients, perform radiation monitoring and decontamination at the scene.  ED NOTIFICATION AND PREPARATION First responders must communicate with hospitals prior to arrival to allow adequate preparation and provide incident information such as circumstances of the event, number of victims, traumatic injuries, type of radiologic insult, and identification of radioactive material. Extent of completed patient decontamination should also be relayed. The hospital disaster plan should include steps that need to be initiated by the ED upon notification to prepare for a radiologic event (Table 10-6). The hospital protocol should instruct ED personnel on how to contact predetermined local radiation specialists and health physics profes sionals. These specialists may assist by monitoring radiation doses of personnel, surveying personnel and areas for contamination, directing contamination control and decontamination efforts, and disposing of contaminated wastes. If radiation monitors are not available, patients should undergo decontamination and then be surveyed for residual contamination when monitoring equipment is available. TRIAGE PRINCIPLES When there are multiple victims, field triage protocols will designate patients as minor, delayed, immediate, or deceased depending on physical trauma or burns. Do not alter triage principles based solely on radiation exposure. Because radioactive contamination is never immediately life-threatening, do not delay treatment of life-threatening injuries for radiologic surveying. Morbidity and mortality from ion izing radiation injuries increase dramatically in the face of physical trauma, thermal burns, and other significant medical conditions. In a mass-casualty event that could include blast injuries in addition to radiologic insult, resources may be limited and will require a coordi nated approach to develop the best management plan. TREATMENT Because most radiation injuries are not immediately life-threatening, there is usually time to determine whether the patient was irradiated, externally contaminated, or internally contaminated. Early treatment decisions are based on biologic dosimetry, including the signs and symptoms evident in the first 24 to 48 hours and corresponding laboratory test results. 14,16  DECONTAMINATION OF EXTERNALLY CONTAMINATED PATIENTS It is highly unlikely that the radioactivity from a contaminated patient would pose a significant risk to healthcare personnel. However, the goal of decontamination measures is to decrease total exposure of the patient and staff, by minimizing radiation exposure from a source external to the body to a level that is as low as reasonably achievable ( Table 10-7). This is accomplished by minimizing time of exposure and the quantity of radioactive materials in the area, as well as maximizing distance and shielding from the source. 14,16  ACUTE RADIATION SYNDROME Patients exposed to ionizing radiation but who are not internally or externally contaminated pose no risk to healthcare workers, and decontamination is not needed. Immediate treatment of the irradiated patient is directed toward alleviating the symptoms of the prodromal phase. Pain can be managed with acetaminophen and opioids. Because the patient may be at risk for significant GI bleeding if the exposure dose is more than 5 to 6 Gy, avoid using NSAIDs. 8 Administer antiemetics for nausea and vomiting.

the irradiated patient is directed toward alleviating the symptoms of the prodromal phase. Pain can be managed with acetaminophen and opioids. Because the patient may be at risk for significant GI bleeding if the exposure dose is more than 5 to 6 Gy, avoid using NSAIDs. 8 Administer antiemetics for nausea and vomiting. Ondansetron or other 5-hydroxytryptamine-3 antagonists are effective. 17 Use antidiarrheal agents such as loperamide as needed. Management of GI syndrome also includes use of a fluoro quinolone for 2 to 4 days after an acute exposure.14 Perform a targeted history and physical exam. Note time of onset of all symptoms, especially vomiting and diarrhea, which are important in biologic dosimetry. Observe for abnormal vital signs suggestive of acute 21 02 03 04 0 Days Lymphocytes and Neutrophils (x 103) Exposure Prodromal phase Latent phase Bone marrow depression phase Recovery phase Platelets (x 105) Platelets Hemoglobin Neutrophils Lymphocytes Hemoglobin grams/dL 4FIGURE 10-1. Typical hematologic course and clinical stages after sublethal (~3 Gy/300 rad) exposure to total-body irradiation. TABLE 10-6 ED Preparation Initiate hospital disaster plan •   Mobilize hospital radiation experts (radiation safety officer, nuclear medicine and radiation oncology experts and staff). •   Request dosimeters for staff and radiation monitoring and survey instruments. Prepare the ED •   Establish an ad hoc triage area based on the location designated in the hospital disaster plan. •   Establish a “contaminated” area and “clean” area separated by a buffer zone using ropes, tape, and signs to designate areas. •   Remove contaminated outer garments when leaving contaminated area and have your body surveyed with a radiation meter prior to leaving the area. •   Cover floors with plastic or paper secured with heavy tape. •   Remove pregnant women, nonessential personnel, and nonessential equipment. •   Request extra gloves, other medical supplies, and extra large plastic bags for disposal. Use standard precautions to protect staff •   Staff should wear a water-resistant gown, cap, and shoe covers to keep contaminants off skin and clothes. •   Double-glove with inner glove taped in place, changing the top pair after handling contaminated items and between patients. •   N95 masks, if available, are recommended, but surgical masks should be adequate. •   Survey hands and clothing at frequent intervals with a radiation meter. •   Dosimeters, if available, should be worn at the collar, under protective clothing. Tintinalli_Sec02_p0019-0052.indd 50 7/30/19 4:59 PM

nd between patients. •   N95 masks, if available, are recommended, but surgical masks should be adequate. •   Survey hands and clothing at frequent intervals with a radiation meter. •   Dosimeters, if available, should be worn at the collar, under protective clothing. Tintinalli_Sec02_p0019-0052.indd 50 7/30/19 4:59 PM CHAPTER 10:  Radiation Injuries      51 radiation syndrome, including fever, hypotension, tachycardia, and tachypnea. Monitor for impaired level of consciousness, ataxia, motor or sensory deficits, reflex abnormalities or papilledema, abdominal tenderness, and GI bleeding. Complete laboratory testing as soon as possible. Biologic dosimetry uses laboratory analyses (e.g., rate and nadir of lymphocyte depletion) and clinical signs to estimate absorbed dose. Cytogenetic analysis for chromosomal aberrations (dicentrics) is the gold standard for biodosimetry. Contact the Radiation Emergency Assistance Center/Training Site for assistance with obtaining chromosomal testing. Obtain a baseline CBC with differential and absolute lymphocyte count in the ED and check a CBC every 6 hours for 24 to 48 hours, monitor ing for lymphocyte depletion. Also obtain a baseline serum amylase and C-reactive protein, because dose-dependent increases are expected after 24 hours in a significant exposure. If vomiting and diarrhea occur in the first 2 to 3 hours (dose estimated to >2 Gy), consider the need for human leukocyte antigen typing in anticipation of pancytopenia requiring further management. This could include administration of blood products, cytokines, colony-stimulating factors, bone marrow cells, or stem cell transplant. 18 Consultation with a hematologist/oncologist is recommended. Management of acute radiation syndrome is focused mainly on the support and recovery of the hematologic system, including bridging cytopenic gaps and managing subsequent infections. Patients may require prophylactic antibiotics, antifungals, and antivirals during their course or appropriate monotherapy for documented infections. Consultation of an infectious disease specialist is advised for management of radiation-induced neutropenia. Monitor patients with large exposures who survive the acute phase for severe infectious and metabolic complications. Treat multiorgan failure from a large radiation exposure with standard supportive measures. Other management issues include maintaining strict environmental control and neutropenic precautions, minimizing invasive procedures, and early surgery and wound closure.  LOCAL RADIATION INJURY Management of local radiation injury focuses on analgesia, meticulous wound care, and infection control. Analgesia is important in the early management of cutaneous radiation injury. Cutaneous radiation injury differs from thermal burns in that the cutaneous injury continues to evolve and may not be visible to the naked eye. The primary goal of treatment is interruption of radiation-induced inflammation in the dermis. Perform traditional burn care, including burn dressings, surgical debridement, and skin grafting, when indicated. Consider applying topical steroids such as betamethasone to control local inflammation, giving vitamin A, C, and E supplementation, and administering pentoxifylline to decrease blood viscosity and increase blood flow. 14,19 Silver-based creams such as sulfadiazine can be used. Hyperbaric oxygen may be considered. Systemic steroids are not recommended. 19 Although inpa tient treatment may not always be required, close follow-up is essential given the potential for ongoing evolution of cutaneous injury.

cosity and increase blood flow. 14,19 Silver-based creams such as sulfadiazine can be used. Hyperbaric oxygen may be considered. Systemic steroids are not recommended. 19 Although inpa tient treatment may not always be required, close follow-up is essential given the potential for ongoing evolution of cutaneous injury.  INTERNALLY CONTAMINATED PATIENTS Internal contamination generally does not produce early symptoms but should be considered if persistently high radiation survey readings are noted and with all nose or mouth contamination cases. Obtain a 24-hour urine collection for possible radionuclide identification. Collect other specimens depending on exposure with or without contamination (Table 10-8). Consult radiation experts for treatment with cathartics, activated charcoal, gastric lavage, and radionuclide-specific decorporation agents (Table 10-9). Duration of therapy is based on dose estima tions from radiochemical measurements of urine and fecal samples. TABLE 10-7 Steps of Patient Decontamination Assess external contamination •   Contact radiation safety officer. •   Assess contamination with radiation survey meter (Geiger counter). •   Evaluate for radioactive shrapnel. Easily accessible pieces should be removed with a forceps and placed in a lead container. •   Document contamination pattern on a body diagram. •   Swab each nostril separately to estimate level of internal contamination of the lungs. Decontaminate whole body •   Carefully cut and roll clothing away from the face to contain contamination. •   Double bag clothing and label as hazardous waste. •   Wash wounds first with saline or water. •   If facial contamination is present, rinse as appropriate. •   Gently cleanse intact skin and avoid scrubbing. •   Repeat patient scan with radiation survey meter. Repeat washing until radiation is <2 times background. Avoid scrubbing. •   Cover wounds with waterproof dressing. TABLE 10-8 Specimens for Medical Assessment Specimen/Type of Analysis Reason Mechanism Suspected radiation exposure Check a CBC every 6 h for 24–48 h Establish baseline and assess lymphocyte depletion as an early predictor of dose. Venipuncture Serum amylase and CRP, repeat daily for 3 d Parotid glands are sensitive to radiation; amylase will rise if exposed to >0.5 Gy. Venipuncture Blood: chromosomal analysis (dicentrics) Gold standard for estimating dose. Venipuncture. Call REAC/TS for assistance. Urine: routine urinalysis Establish baseline kidney function, especially if internal contamination is suspected. Clean catch Suspected external contamination Swabs of body orifices and samples from dressings/ wounds Assess internal contamination and identify radionuclide. Use separate saline or water-moistened swabs to wipe the inside of each nostril, ear, and mouth. Suspected internal contamination Urine bioassay: 24-h specimen; repeat for 4 d Radionuclide identification Standard specimen containers Consider feces bioassay in consult with radiation expert

ion and identify radionuclide. Use separate saline or water-moistened swabs to wipe the inside of each nostril, ear, and mouth. Suspected internal contamination Urine bioassay: 24-h specimen; repeat for 4 d Radionuclide identification Standard specimen containers Consider feces bioassay in consult with radiation expert Abbreviations: CRP = C-reactive protein; REAC/TS = Radiation Emergency Assistance Center/Training Site. TABLE 10-9 Internal Contamination Treatment Radionuclide Ionizing Radiation Treatment Mechanism of Action Usual Administration Iodine (I-131) β, γ Potassium iodide Block thyroid uptake 130 milligrams PO for adults Plutonium (Pu-239) Ca-DTPA or Zn-DTPA Chelation 1 gram in 250 mL NS or 5% dextrose in water over 60 min Tritium (H-3) β Water Dilution Oral: 3–4 L a day for 2 wk Cesium (Cs-137) β, γ Prussian blue Decrease GI uptake 1 gram in 100–200 mL water three times a day for several days Uranium (U-235) α Bicarbonate Urine alkalinization 2 ampules in 1 L NS at 125 mL/h Abbreviations: DTPA = diethylenetriamine pentaacetate; NS = normal saline. Tintinalli_Sec02_p0019-0052.indd 51 7/30/19 4:59 PM

m (Cs-137) β, γ Prussian blue Decrease GI uptake 1 gram in 100–200 mL water three times a day for several days Uranium (U-235) α Bicarbonate Urine alkalinization 2 ampules in 1 L NS at 125 mL/h Abbreviations: DTPA = diethylenetriamine pentaacetate; NS = normal saline. Tintinalli_Sec02_p0019-0052.indd 51 7/30/19 4:59 PM 52 SECTION 2: Disaster Management PRENATAL EXPOSURES Fetal sensitivity to radiation depends on a number of factors, including radiation dose and gestational age. The radiation dose to the fetus may not be the same as the dose to the mother, because the fetus is shielded in part by the uterus and surrounding tissues. External exposure of alpha and beta particles is unlikely to reach the fetus, but gamma and radiographs directed toward a pregnant woman’s abdomen could harm the fetus. In addition, internal contamination could expose the fetus to higher radiation, as the radioactive material could accumulate in the bladder of the pregnant woman. The health effects of radiation on the fetus are dependent on the ges tational age. Before about 2 weeks of gestation, there is an all-or-none phenomenon, and if the exposure does not result in death of the embryo, no observable effects are expected. An exposure of greater than 0.1 Gy is expected to be lethal, resulting in resorption of the conceptus. From 2 to 8 weeks, organogenesis occurs. During this time, the embryo is at risk for congenital malformations and growth retardation. In cases of sub stantial exposures, there is a significant risk of major malformations of the neurologic and motor systems. After 8 weeks of gestation, exposures are associated with an increased risk of mental retardation and miscar riage. Throughout gestation, an exposure of less than 0.05 Gy would not be expected to produce an increased risk of noncancer health effects. 20 Consult with radiation medicine physicians regarding fetal dose estimation and risk assessment counseling for the expecting parents. 21 For additional discussion, see Chapter 99, “Comorbid Disorders in Pregnancy. ” SOURCES OF ASSISTANCE Two organizations provide medical advice for the treatment of radia tion casualties. The Radiation Emergency Assistance Center/Training Site, sponsored by the Department of Energy and managed by the Oak Ridge Institute for Science and Education, provides training programs, consultation assistance, and treatment capabilities, and can dispatch an emergency response team of health professionals to assist at an accident site. After initial treatment and decontamination actions are complete, REAC/TS may also accept severely contaminated or irradiated patients for transfer to its facilities for more definitive care. Radiation Emergency Assistance Center/Training Site (REAC/TS) Oak Ridge Institute for Science and Education P .O. Box 117, MS 39, Oak Ridge, TN 37831-0117 865-576-3131 (daytime phone; ask for REAC/TS) 865-576-1005 (24-hour emergency number) Another organization available for consultation is the Medical Radiobiology Advisory Team, sponsored by the Department of Defense and managed by the Armed Forces Radiobiology Research Institute. Medical Radiobiology Advisory Team Armed Forces Radiobiology Research Institute National Naval Medical Center 8901 Wisconsin Avenue, Building 42 Bethesda, MD 20889-5603 301-295-0316 301-295-0530 (24-hour emergency number) The U.S. Department of Health and Human Services sponsors the Radiation Emergency Medical Management Guidance on Diagnosis and Treatment for Health Care Providers. Information can be found at http://www.remm.nlm.gov. REFERENCES The complete reference list is available online at www.TintinalliEM.com. Tintinalli_Sec02_p0019-0052.indd 52 7/30/19 4:59 PM