Disease class: Radiation injuries
Also known as
- ARS
Symptoms and signs
- Anorexia
- Nausea
- Vomiting
- Diarrhoea
- Haematemesis
- Pain
- Confusion
- Coma
- Haemoptysis
- Dyspnoea
- Erythema
- Oedema
- Alopecia
- Nail loss
- Tooth loss
- Blistering
- Desquamation
- Pain
- Haemorrhage
- Bruising
- Weakness
- Numbness
Pathological features
- Gastrointestinal dysfunction
- Gastroenteritis
- Gingivitis
- Necrosis
- Neurological dysfunction
- Neuritis
- Cerebral oedema
- Confusion
- Coma
- Pulmonary dysfunction
- Pneumonitis
- Pulmonary oedema
- Cardiovascular dysfunction
- Myocarditis
- Heart block
- Vasculitis
- Haemorrhage
- Mucocutaneous dysfunction
- Dermatitis
- Tissue necrosis
- Dental caries
- Haematological dysfunction
- Sepsis
- Thrombocytopenia
- Neutropenia
- Lymphopenia
- Aplastic anaemia
- Musculoskeletal dysfunction
- Myositis
- Osteonecrosis
- Multiple organ failure
Aetiology
- ARS follows exposure to an ionising radiation dose of more than 1 Sievert.
- A dose of 4-5 Sieverts or more, absorbed within a short time period, causes death in 50% of patients within 30 days.
Pathophysiology
- High energy ionising radiation causes damage to all exposed biological structures.
- The energy of the radiation can result in tissue damage similar to thermal or electrical burns. A sufficiently high dose will vaporise living tissue.
- The most radiation-sensitive structures within cells are the genetic materials. DNA and RNA are easily damaged or destroyed, leaving the cells incapable of functional protein synthesis.
- Successful mitosis cannot occur so destroyed cells are not replaced.
- The cell cannot repair physical damage.
- Many cells undergo apoptosis (programmed cell death).
- Tissues start to break apart.
Management
- Iodine tablets can saturate the biosynthesis pathways inside the thyroid gland. This minimises the uptake of iodine radioisotopes from the environment and reduces the risk of thyroid cancer.
- Supportive care is vital to minimise disability and death in the short term.
- In the long term, these patients should be monitored for signs of malignancy and bone marrow dysfunction.
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