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Similar to Acute radiation syndrome
Acute radiation syndrome
- 1.
- 2. • Effect ofionizing radiation on organism • Hiroshima & Nagasaki • Chernobyl
- 3. Early lethal effects •Considered to be death occurring within a few weeks • High intensity exposure to radiation • Three distinct modes of death – At very high dose 100Gy • Cerebrovascular syndrome – death 24-48 hrs – Intermediate dose 5-12Gy • Gastrointestinal syndrome – extensive bloody diarrhea • Death in 9-10days – Lower dose 2.5 to 5gy • Hematopoetic syndrome – death weeks to 2 months
- 5. Early lethal effects •Stages of ARS – Prodromal radiation syndrome – Latent period – Manifestation of illness – Recovery or death
- 6. Prodromal radiation syndrome •Early symptoms soon after irradiation • Last for limited period • May clear up after few days • Onset of symptoms within 5-10 min of exposure • Maximum about 30 min • Persists for few days
- 7. • Signs &symptoms – Gastrointestinal – Neuromuscular • GI – anorexia, nausea, vomiting, diarrhea, intestinal cramps, salivation, fluid loss, dehydration, weight loss • NM – Easy fatiguablity, apathy, sweating, fever, headache, hypotension
- 8. • LD 50symptoms – Easy fatigability, anorexia, nausea, vomiting • Supralethal dose – Diaarhea, fever, hypotension • Followed by latent period •
- 9. • Diagnosis ofARS – Drop in lymphocyte count after an exposure as low as 0.5Gy – Circulating lymphocytes most radiosensitive – Fall in absolute lymphocyte count – Chromosomal abberation analysis from lymphocytes – Lower limit of dose detected is 0.2Gy
- 10. Cerebrovascular syndrome • Totalbody dose of 100Gy – death in 24-48 hrs • All systems damaged • Death occurs before other symptoms have time to appear • Severe nausea and vomiting followed by disorientation, loss of coordination, respiratory distress diarrhea, seizures, coma, death
- 11. • Cause ofdeath is damage to microvasculature • Increase in fluid content of the brain
- 12. Gastrointestinal syndrome • Morethan 10Gy • Usually between 3 & 10 days • Nausea, vomiting, prolonged diarrhea • Prolonged diarrhea bad sign • Dehydration, loss of weight, emaciation, death
- 13. • Depopulation ofepithelial lining of GI tract • GI lining is self renewing tissue – Stem cell compartment – achilles heel – Differentiating compartment – Mature functioning cells • Radiation of 10Gy sterilizes the dividing cells • As the surface of villi is sloughed off there are no replacement • Villi begin to shorter and shrink • Completely denuded of villi • It doesnot occur until about 9-10 days • Death from denuding of gut occurs
- 14. Hematopoetic syndrome • 2.5Gy to 5 Gy • Damage to hematopoetic system • Mitotically active precursor cells are sterilised • Subsequent supply of RBC, WBC & platelets diminished • The time of potential crisis is delayed for some weeks – Mature cells begin to die off – Supply of new cells inadequate to replace
- 15. • LD50 – Dosethat causes mortality rate of 50% population in a specified period – The peak incidence of death from hematologic damage occurs about 30 days after exposure (upto 60days) – LD50/60
- 16. • Symptoms – Chills,fatigue, petechiae – Oral ulceration, hairloss – Infection, fever – granulocyte depression & impairment in immune mechanism – Bleeding, Anemia – platelet dysfunction – Anemia from RBC depression does not occur – Infection – cause of death
- 17. • Mean lethaldose • LD50/60 – 3.25Gy in young healthy individual – 4Gy in conservative care, modern well equipped hospital
- 18. Pulmonary syndrome • 8Gy or more • 130 days after irradiation
- 19. Cutaneous radiation injury •Radiation injury to the skin • Non penetrating β particles & low energy photons • Injury becomes apparent in hours • Threshold local dose of epilation 3Sv & erythema 6Sv • Itching, tingling, epilation, erythema, edema, dry desquamation, wet desquamation, ulceration & necrosis • Life threatening concomitant infection
- 20. Symptoms MILD (1–2 Gy) MODERATE (2–4 Gy) SEVERE (4–6Gy) SEVERE (6–8 Gy) LETHAL (>8 Gy) Lymphocytes (G/L) (days 3–6) 0.8–1.5 0.5–0.8 0.3–0.5 0.1–0.3 0.0–0.1 Granulocytes (G/L) >2.0 1.5–2.0 1.0–1.5 ≤0.5 ≤0.1 Diarrhea None None Rare Appears on days 6–9 Appears on days 4–5 Epilation None Moderate, beginning on day 15 or later Moderate or complete on days 11–21 Complete earlier than day 11 Complete earlier than day 10 Latency period (d) 21–35 18–28 8–18 7 or less None Medical response Hospitalizat ion not necessary Hospitalization recommended Hospitalizati on necessary Hospitalizati on Urgently necessary Symptomatic treatment only
- 21. Treatment • Radiation <4-5Gy –Watch carefully – Symptomatic treatment • >5Gy – p/o death from hematopoetic syndrome – Isolation & antibiotics to prevent infection – Control of bleeding
- 22. • BMT – Torescue patients exposed to supralethal dose – Window of dose within which the BMT is useful – Narrow 8-10Gy – >10Gy – no use