EMS AND DISASTER MEDICINETREATMENT
■ Skin and mucous membrane decontamination with irrigation
■ Supportive care
A nuclear physicist presents to the ED after total-body radiation exposure of
uncertain dose. On arrival he appears acutely ill with nausea, vomiting, and
disorientation. What can you predict regarding his likely clinical course?
The rapid onset of prodromal and CNS symptoms indicates an extremely
high-exposure dose. This patient will likely develop refractory hypotension, circu-
latory collapse, and death in 24–72 hours despite aggressive intensive care.RADIATION INJURIESMost radiation exposures occur accidentally in an industrial setting, with the
most common overall site of injury =hands.
Types of exposure:
■ Contamination: Either external via skin or internal via inhalation or
ingestion
■ These patients are “radioactive.”
■ For example, the recent intentional poisoning of a former Russian agent
with Polonium-210
■ Irradiation
■ Patients pose no risk to other people.
PATHOPHYSIOLOGY
■ Ionizing radiation(alpha particles, beta particles, neutrons, gamma rays)
has short wavelength, high frequency, and high energy
■ High-level exposure →direct cell death.
■ Low-level exposure →formation of free radicals →breakage of DNA and
RNA strands →cell injury and/or death.
■ Rapidly dividing cells (bone marrow, GI, and reproductive) are most sensitive.
Lethal dose 50 (LD 50 )is the dose that will kill 50% of the exposed popula-
tion within 60 days =approximately 450 radiation-absorbed dose (rad) or
4.5 gray (Gy).
Local Skin Exposure
Results in cutaneous changes ranging from erythema to overt skin necrosis
and ulceration, depending on dose
Acute Radiation Syndrome (ARS)
Occurs after whole body ionizing radiation exposure to a dose of >2 Gy. It is
divided into three phases: Prodromal, latent, and manifest illness (see Table 20.11).
PRODROMALPHASE
■ Autonomic nervous system response to radiation
■ Primarily gastrointestinal symptoms: N/V, diarrhea
■ Higher exposure =earlier, longer, and more severe symptoms, including
bloody diarrhea.
Higher radiation exposure is
associated with earlier
prodrome phase and shorter
latent phase.