From the Guidelines
Radiation sickness, also known as Acute Radiation Syndrome (ARS), is a life-threatening condition that occurs when the body is exposed to a high dose of ionizing radiation, resulting in damage to the hematopoietic, gastrointestinal, and cerebrovascular systems.
Pathophysiology of ARS
The pathophysiology of ARS involves the damage of rapidly dividing cells, such as:
- Hematopoietic cells: responsible for producing blood cells, leading to bone marrow failure and infection 1
- Gastrointestinal cells: leading to diarrhea, nausea, and vomiting, and increasing the risk of infection and sepsis 1
- Cerebrovascular cells: leading to cerebral edema, increased intracranial pressure, and cerebral anoxia, resulting in death 1
Clinical Syndromes
The clinical syndromes associated with ARS include:
- Hematopoietic syndrome: characterized by bone marrow failure, infection, and bleeding, occurring at doses exceeding 1 Gy 1
- Gastrointestinal syndrome: characterized by diarrhea, nausea, and vomiting, occurring at doses exceeding 10 Gy 1
- Cerebrovascular syndrome: characterized by cerebral edema, increased intracranial pressure, and cerebral anoxia, occurring at doses exceeding 20 Gy 1
Phases of Radiation Injury
The phases of radiation injury include:
- Prodromal phase: characterized by nausea, vomiting, and diarrhea, occurring within hours to days after exposure
- Latent phase: characterized by apparent recovery, lasting from several days to weeks
- Manifest illness phase: characterized by severe symptoms, such as infection, bleeding, and organ failure, occurring weeks after exposure
- Recovery or death phase: depending on the severity of the exposure and the effectiveness of treatment 1
From the Research
Pathophysiology of Radiation Sickness (Acute Radiation Syndrome)
The pathophysiology of Radiation Sickness, also known as Acute Radiation Syndrome (ARS), is a complex process that involves damage to multiple organ systems due to exposure to high levels of ionizing radiation. The severity of ARS depends on the dose and duration of radiation exposure, as well as the individual's overall health and medical treatment received 2, 3, 4, 5, 6.
Organ Systems Affected
The main organ systems affected by ARS include:
- Hematopoietic system: damage to bone marrow leads to a decrease in blood cells, including white blood cells, red blood cells, and platelets 2, 3, 4
- Gastrointestinal system: damage to the lining of the gut leads to nausea, vomiting, diarrhea, and abdominal pain 3, 4, 5
- Cutaneous system: damage to the skin leads to burns, blisters, and ulcers 2, 5
- Neurovascular system: damage to the brain and nervous system leads to seizures, tremors, and loss of coordination 3, 6
Phases of ARS
The phases of ARS include:
- Prodromal phase: 0-2 days after exposure, characterized by nausea, vomiting, and diarrhea 3
- Latent phase: 2-20 days after exposure, during which the individual may appear to be recovering, but is actually experiencing damage to their bone marrow and other organs 3, 4
- Manifest illness phase: 21-60 days after exposure, during which the individual experiences the full effects of ARS, including infection, bleeding, and organ failure 3, 4, 6
Treatment and Management
Treatment and management of ARS involve:
- Supportive care, including fluids, nutrition, and pain management 2, 3, 6
- Medications to stimulate blood cell production, such as granulocyte-colony stimulating factor (G-CSF) 3
- Antibiotics, antiviral, and antifungal agents to prevent and treat infections 3, 6
- Surgery to repair damaged tissues and organs 5, 6
- Hematopoietic stem cell transplantation in severe cases 2, 3, 4