ACUTE WHOLE BODY IRRADIATION

• we get information on this from accidents such as chernobyl and from hirsoshima and nagasaki
• SUDDEN, ACUTE EXPOSURES to the whole body or most of the body
• Must be with penetrating beams : x-ray, gamma rays, alpha, beta, gamma, protons
• Must have nonspecific life shortenting – group must have a life expectancy shorter then the norm
• Dose dependent
• 5% shortening in life for each 100 cGy received to the whole body
• no survival above 1000 cGy

Requirments:

• must be total body
• must be sudden onset

Median Lethal Dose (mean):

LD/50/60 : lethal dose of 50% of the population in 60 days (325 – 400 cGy)

PROCESSES THAT CAUSE DEATH:

1. Necrosis (cell death of most sensitive organs first)

• lymphatic system (spleen)
• bone marrow
• GI tract (crypts of Leiberkuhn)
• Gonads
• Skin

2. Hemmorhage (bleeding)

• Develop anemia because of internal bleeding due to hemorrhaging!!!  (Loss of Blood anemia)

3. Infection

• Due to lymphochytes dying (n=1, Dq = 0)

TYPICAL STAGES (4  / all are dose dependent):

1. Prodromo stage
• Nausuea, vomiting, diahrehea (NVD)
• Fright
• Lasts days to minutes depending on Dose

2. Latent stage
   • The calm before the storm

3. Manifest illness
   • Where actual processes occurring in Latent Stage are now apperant

4. Recovery or Death

**after an Acute Exposure the patient will go through all of these stages

SYNDROMES:

  (4 of them in increasing order of dose)

1. Sub-clinical Syndrome (50 cGy – 200cGy)

• NVD
• More chance of recovery
• Major problem might be if the person irradiated has children in the future (mutations and aberrations may occur to the future generation (spermatagonium can be affected))

2. Bone Marrow Syndrome / Hemopeotic Syndrome  ( 300 – 800 cGy)

• Prodromal stage lasts hours (NVD)
• Latent Stage up to 3 weeks
• WBC’s, platelets being knocked out
• Infection and bleeding sets in
• Manifest Illness Stage lasts 3 – 5 weeks
• Pancytopenia depression of all blood cells (RBC’s go down due to bleeding)
• Infections set in
• Recover or Die based on Dose
• Location of patient to a hospital with antibiotics is important
• Death or Recovery occurs after 6 weeks

3. GI Syndrome (500 – 1200 cGy)

• Death occurs at 1000cGy
• 3 – 10 days total
• prodromal stage : severe NVD lasts hours
• Latent Stage : 2 – 5 days (flattening of the villi due to lack of crypt cells)
• Manifest Illness : on the 5th – 10th day
• Severe diahhrea
• Complete exhaustion
• Transfusions are given as a last resort
• Fluids and broad spectrum antibiotics are given

4. CNS Syndrome (Cerebro Vascular Syndrome)

Person dies from CNS damage before onset of anything else!!!

• Over 2000 cGy
• 2-3 days till death
• Prodromal Stage : last minutes with nervousness, NVD, burning, restlessness, convulsions
• Latent Stage : lasts several hours
• Manifest Illness : lasts 5 – 6 hours with watery diahhrea, convulsiuons, coma, then death
• Walls of blood supply to the brain collapse and the brain receives no blood