Emergency department care

In general, treatment of conventional injuries and illness takes precedence over radiation concerns. The quantity of radioactive material that a contaminated individual carries on his or her body is unlikely to present a significant radiation risk to hospital workers. No cases are known of healthcare personnel becoming acutely ill caring for contaminated or irradiated victims of radiation accidents. Critically ill and injured patients should be moved into critical care areas of the hospital and should be decontaminated during resuscitation. In a mass casualty event, most patients arrive without prehospital decontamination necessitating appropriate screening strategies in accordance with the Hospitals Incident Command Structure (HICS).

Specific treatments

Patients with localized irradiation that present with cutaneous injury should be treated in the same manner as those with thermal burns. Pain control and infection prophylaxis are the mainstays of treatment. In the cases of severe burns, vasodilator therapy, grafts, or amputations may be necessary.

After whole-body radiation exposure, appropriate decontamination should occur. Patients who present with prodromal symptoms should be treated supportively with intravenous fluids, analgesics, and antinausea medication. For exposures of around 5 Gy, most experts recommend supportive care, antibiotics for infection, consideration of cytokine therapy, and transfusions as needed. Blood products should be leukocyte-poor and irradiated to 25 Gy, but transfusions should not be given prophylactically because they may blunt the stimuli for cell regeneration. For exposures greater than 5 Gy, death from gastrointestinal syndrome is highly likely. Along with antibiotics and platelet transfusions as needed, physical trauma and avoidance of infection (isolation) should be stressed.

In cases of internal ingestion or contamination of unknown radioactive materials, some measures (eg, lavage, charcoal) to decrease absorption may be effective and can be used if not contraindicated. Similarly, specific therapies exist to remove some internally deposited radionuclide albeit with limited efficacy. These treatments are often in limited supply, complex in action, and associated with significant risks. Thoughtful and critical analysis should be take place prior to administration.

Internal contamination by radioactive iodine can be treated with saturated solution of potassium iodide (SSKI), a blocking agent that reduces uptake of radionuclide in the thyroid. SSKI is most effective when taken within a few hours of exposure. In reactor accidents involving radioactive iodine, massive quantities are released into the environment. Both exposed victims and rescue personnel should take SSKI to reduce thyroid uptake of radioiodine to reduce risk of future malignancies. Specific dosages for SSKI administration can be viewed at Guidance for Industry – KI in Radiation Emergencies—Questions and Answers.

Chelating agents, such as penicillamine, bind specific radioactive metals causing decreased tissue uptake and increased excretion. Exposure to isotopes of cesium can be treated with ferric hexacyanoferrate (Prussian blue) to decrease gastrointestinal absorption. Agents such as Ca-DTPA and Zn-DTPA can be administered after internal contamination with substances such as americium or plutonium. Administration of specific agents should be done in consultation with professionals familiar with these agents.

Further inpatient care

During periods of infection, antibiotics should be tailored toward the source of infection. If absolute neutrophil count (ANC) is less than 500 cells/mm³, most experts recommend prophylactic antibiotics including a fluoroquinolone, an antiviral agent (acyclovir in those with a history of herpes simplex virus), and an antifungal agent. Once fever and infection occur, broader antibiotics with additional antipseudomonal coverage should be initiated.

The use of bone marrow transplants remains controversial. Of the 13 Chernobyl victims who received bone marrow transplants, only 2 survived, one of whom had autologous marrow repopulation; thus only one survivor was thought to be saved by a bone marrow transplant. The dose window appropriate for bone marrow transplantation is thought to be between 8 and 10 Gy, as those who receive less than 8 Gy may survive with conservative treatment, antibiotics, and transfusions, whereas those who receive greater than 10 Gy uniformly die.

Administration of hematopoietic growth factors to stimulate bone marrow post irradiation also remains investigational. Past studies have shown a benefit in animal models increasing neutrophil counts in primates irradiated with Cobalt-60.

In a 2004 paper, Waselenko et al proposed recommendations for giving colony-stimulating factors (CSF) to victims of radiation exposure. His team recommended giving granulocyte-macrophage colony-stimulating factor (GM-CSF) to those who receive more than 3 Gy of radiation and in those with multiple injuries who are exposed to more than 2 Gy. Recommended doses include initiating therapy with filgrastim at 5 m/kg/day or sargramostim at 250 m/m²/day subcutaneously immediately after exposure and continuing until absolute neutrophil count increases to greater than 1,000 cells/mm³. Alternative treatment with subcutaneous pegfilgrastim.

Date: 2015-01-12; view: 974