Download The Brochure (PDF)pdf icon Show Acute Radiation Syndrome (ARS) (sometimes known as radiation toxicity or radiation sickness) is an acute illness caused by irradiation of the entire body (or most of the body) by a high dose of penetrating radiation in a very short period of time (usually a matter of minutes). The major cause of this syndrome is depletion of immature parenchymal stem cells in specific tissues. Examples of people who suffered from ARS are the survivors of the Hiroshima and Nagasaki atomic bombs, the firefighters that first responded after the Chernobyl Nuclear Power Plant event in 1986, and some unintentional exposures to sterilization irradiators. The required conditions for Acute Radiation Syndrome (ARS) are:
The three classic ARS Syndromes are:
The four stages of ARS are:
These stages are described in further detail in Table 1
* The absorbed doses quoted here are “gamma equivalent” values. Neutrons or protons generally produce the same effects as gamma, beta, or X-rays but at lower doses. If the patient has been exposed to neutrons or protons, consult radiation experts on how to interpret the dose. † The LD50/60 is the dose necessary to kill 50% of the exposed population in 60 days. ‡ The LD100 is the dose necessary to kill 100% of the exposed population Cutaneous Radiation Syndrome (CRS)The concept of cutaneous radiation syndrome (CRS) was introduced in recent years to describe the complex pathological syndrome that results from acute radiation exposure to the skin. ARS usually will be accompanied by some skin damage. It is also possible to receive a damaging dose to the skin without symptoms of ARS, especially with acute exposures to beta radiation or X-rays. Sometimes this occurs when radioactive materials contaminate a patient’s skin or clothes. When the basal cell layer of the skin is damaged by radiation, inflammation, erythema, and dry or moist desquamation can occur. Also, hair follicles may be damaged, causing epilation. Within a few hours after irradiation, a transient and inconsistent erythema (associated with itching) can occur. Then, a latent phase may occur and last from a few days up to several weeks, when intense reddening, blistering, and ulceration of the irradiated site are visible. In most cases, healing occurs by regenerative means; however, very large skin doses can cause permanent hair loss, damaged sebaceous and sweat glands, atrophy, fibrosis, decreased or increased skin pigmentation, and ulceration or necrosis of the exposed tissue. Patient ManagementTriage: If radiation exposure is suspected:
Diagnosis If a patient received more than 0.05 Gy (5 rads) and three or four CBCs are taken within 8 to 12 hours of the exposure, a quick estimate of the dose can be made (see Ricks, et. al. for details). If these initial blood counts are not taken, the dose can still be estimated by using CBC results over the first few days. It would be best to have radiation dosimetrists conduct the dose assessment, if possible. If a patient is known to have been or suspected of having been exposed to a large radiation dose, draw blood for CBC analysis with special attention to the lymphocyte count, every 2 to 3 hours during the first 8 hours after exposure (and every 4 to 6 hours for the next 2 days). Observe the patient during this time for symptoms and consult with radiation experts before ruling out ARS. If no radiation exposure is initially suspected, you may consider ARS in the differential diagnosis if a history exists of nausea and vomiting that is unexplained by other causes. Other indications are bleeding, epilation, or white blood count (WBC) and platelet counts abnormally low a few days or weeks after unexplained nausea and vomiting. Again, consider CBC and chromosome analysis and consultation with radiation experts to confirm diagnosis. Initial Treatment and Diagnostic Evaluation Figure 1: Andrews Lymphocyte Nomogram 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. Note and record areas of erythema. If possible, take color photographs of suspected radiation skin damage. Consider tissue, blood typing, and initiating viral prophylaxis. Promptly consult with radiation, hematology, and radiotherapy experts about dosimetry, prognosis, and treatment options. Call the Radiation Emergency Assistance Center/Training Site (REAC/TS) at (865) 576-3131 (M-F, 8 am to 4:30 am EST) or (865) 576-1005 (after hours) to record the incident in the Radiation Accident Registry System. After consultation, begin the following (as indicated):
For More HelpTechnical assistance can be obtained from the Radiation Emergency Assistance Center/Training Site (REAC/TS) at (865) 576-3131 (M-F, 8 am to 4:30 pm EST) or (865) 576-1005 (after hours), or on their web site at http://www.orau.gov/reacts/external icon, and the Medical Radiobiology Advisory Team (MRAT) at (301) 295-0316. Also, more information can be obtained from the CDC Health Alert Network at emergency.cdc.gov or by calling (800) 311-3435. ReferencesBerger ME, O’Hare FM Jr, Ricks RC, editors. The Medical Basis for Radiation Accident Preparedness: The Clinical Care of Victims. REAC/TS Conference on the Medical Basis for Radiation Accident Preparedness. New York : Parthenon Publishing; 2002. Gusev IA , Guskova AK , Mettler FA Jr, editors. Medical Management of Radiation Accidents, 2 nd ed., New York : CRC Press, Inc.; 2001. Jarrett DG. Medical Management of Radiological Casualties Handbook, 1 st ed. Bethesda , Maryland : Armed Forces Radiobiology Research Institute (AFRRI); 1999. LaTorre TE. Primer of Medical Radiobiology, 2 nd ed. Chicago : Year Book Medical Publishers, Inc.; 1989. National Council on Radiation Protection and Measurements (NCRP). Management of Terrorist Events Involving Radioactive Material, NCRP Report No. 138. Bethesda , Maryland : NCRP; 2001. Prasad KN. Handbook of Radiobiology, 2 nd ed. New York : CRC Press, Inc.; 1995.
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