Acute Radiation Syndrome Flashcards
ARS
A collection of symptoms associated with high level radiation doses to the entire body over a short period.
Acute Radiation Syndrome aka
ARS or radiation sickness
Syndrome
A collection of symptoms
Protracted
A large exposure all at once
Fractionated
Large exposure over an extended period of time
The three separate dose related syndromes that occur with ARS:
Hematopoietic syndrome
Gastrointestinal syndrome
Cerebrovascular syndrome
The four major response stages that occur with ARS:
Prodromal or initial stage
Latent period
Manifest illness
Recovery or death
Prodromal stage
Occurs within hours after whole body irradiation of 100 rads or more
Symptoms of Prodromal stage
Nausea, vommitting, diarrhea, fatigue, and leukopenia.
Severity of symptoms is dose related - as dose increases symptoms increase
Length of the Prodromal stage
A few hours to a few days, dependent on dose.
Latent period
Occurs after the Prodromal stage, lasts about one week.
Latent
Hidden or invisible
Latent period symptoms
No display of symptoms, general feeling of well being.
During the latent period, either…
Recovery or lethal effects begin to occur. Damage has been done but no visible symptoms
Manifest illness
Begins towards the end of the first week, symptoms begin to become visible.
Manifest
Visible
Some symptoms that occur during the manifest period are
Apathy, confusion, headaches, epilation, exhaustion, severe diarrhea, vommitting, fluid loss, dehydration, decrease in WBC/RBC/platelets, fever, infection, hemorrhage, and cardiovascular collapse
Exposed individuals to ARS may recover if
They received a sub lethal whole body dose of no more than 200-300 rads, if they have survived the first three stages, if medical support is available, recovery may occur within a 3 month period.
Likelihood of death due to ARS increases if
They have received a whole body super lethal dose of more than 600-1000 rads
Hematopoietic syndrome is aka
Bone marrow syndrome
Hematopoietic syndrome is caused when
A dose of 100-1000 rads over whole body, including massive cytopenia (decreased RBC/ WBC/platelets
Hematopoietic system is the most
Radiosensitive system in the human body
Lymphocytes are the most
Sensitive cells of the body
Death occurs primarily as a result of_____________________ during hematopoietic syndrome
Bone marrow destruction
Death occurs secondarily as a result of
Infection and/or hemorrhage
Death may occur within 6-8 weeks with a dose of
200+ rads
Survival time decreases as dose increases
Bone marrow transplants
Can be beneficial to survival
Gastrointestinal syndrome has a threshold of
600 rads and peaks after a dose of 1000 rads (damage won’t get any worse after this dose).
Gastrointestinal syndrome has a latent period lasting up to
5 days
Without treatment, gastrointestinal syndrome will cause death within
3-10 days
With treatment, survival from gastrointestinal syndrome
Will be prolonged a few more days
Death from gastrointestinal syndrome occurs as a result of
epithelial cell damage in the lining of the GI tract, intestinal epithelial tissue cannot be transplanted
During gastrointestinal syndrome, the small intestine is
Most severely affected. Including Catastrophic damage to epithelial cells, death to intestinal crypt cells.
The epithelial lining forms a biologic barrier which separates
Intestinal contents from blood.
The loss of the biologic barrier results in
Massive infection, massive bleeding, and massive dehydration
The walls of the digestive tract include
Mucosa/mucous membrane Sub mucosa Muscularis Serosa (outermost) Lumen (inner/hollow space)
The mucosa/mucous membrane is
The innermost layer, epithelial layer with a semi-permeable membrane.
The barrier between the body and the GI tract
The submucosa is the
Second layer of the digestive tract, just below the mucosa, containing glands, blood vessels, and nerves.
The muscularis is the
Muscular layer of the digestive tract containing two layers of muscles. Its shape is circular and longitudinal and its function is peristalsis (rhythmic muscular contractions)
The serosa of the digestive tract is the
Outermost layer - visceral peritoneum anchored to the abdominal wall by mesentery
Cerebraovasvular syndrome
Occurs when the CNS and cardiovascular system receive doses of 5000 rads or more, the latent period lasts up to 12 hours and death will occur within a few hours to a couple of days. No time for hematopoietic or gastrointestinal syndrome to occur.
Cerebrovascular syndrome is the
Breakdown of the blood-brain barrier.
This allows fluid for blood to leave blood vessels a center the brain tissue causing massive edema to the brain.
Damaged blood vessels during cerebrovascular syndrome permits
Fluid to leak into the brain causing increased intracranial pressure.
Symptoms of cerebrovascular syndrome include
Disorientation, shock, agitation, stupor, ataxia, loss of balance, fatigue, lethargy, seizures, and coma.
Death caused by cerebrovascular syndrome is due to
Massive cerebral edema; cardiovascular system failure
Somatic effect
Biological damage sustained by a living organism as a result of exposure to ionizing radiation
Soma
Body
Early somatic effects versus late somatic effects
Depends on the length of time from irradiation to the appearance of symptoms as a result of irradiation
Genetic effects
Biological effects of radiation to future generations
Stochastic effects
Probabilistic.
May include leukemia and other cancers but cannot be 100% sure radiation caused the effect
Nonstochastic effects
Deterministic effects that can be early or late.
“No doubt” the radiation exposure caused the effect.
Radium watch dial painters (1920’s-1930’s)
Factories primarily in New Jersey, mainly young girls using sable brushes for a fine point, ingested large amounts of radium which incorporated into bone tissue causing decalcification of bone, sarcoma, and carcinoma; radium jaw.
Uranium miners, Navajo (1950’s-1960’s)
50% died of lung cancer from the uranium mines in NM and AZ, mainly Navajo. Employed 15000 miners, who brought home radioactive dose on clothes and contaminated homes and families.
Uranium is a fuel for nuclear power and weapons, is a tradition element (radon, radium), emits alpha, beta, gamma radiation and has a half life of
4.5 billion years!
Early medical radiation workers (1896-1910’s)
Radiologists, dentists, technologists, physicists received high exposures to face and hands due to no protective equipment used. An increased incidence of aplastic anemia and leukemia.
Since the 1940’s
Radiation Workers have NO documented increase in adverse health effects due to their occupational exposure
Thorotrast patients (1925-1945)
An early contrast agent for angiography had an uptake into the liver and spleen leading to an increased incidence of liver cancer, cancer of spleen, biliary carcinoma, and angio sarcoma.
Infant thymus gland patients (1940’s-1950’s)
Thymus gland in infants irradiated to treat enlargement of thymus gland which is located in the superior mediastinum directly adjacent to the thyroid gland.
Marshall Islanders (1946) - Bikini Atoll
Nuclear testing with an unexpected wind shift which carried fallout pattern over inhabited islands. The average dose to thyroid was 12 Gray (1200 rads)
Hiroshima and Nagasaki (1945)
Estimated combined population of 300,000; estimated 80,000 killed immediately, estimated 70,000 injured. All survivors suffered from various degrees of radiation exposure.
Approximately 100,000 survivors studied from Nagasaki/Hiroshima and found
Increased incidence of leukemia, thyroid/lung cancer, bone/breast cancer.
One out of every 3 hundred survivors died of malignancy attributed to the whole body radiation exposure.
Chernobyl, USSR (1986)
Meltdown/explosion at a nuclear power plant, tried to “cover it up” with no international notification, discovered by Swedish monitoring systems. Delay in administering aid resulted in millions developing radiation induced illnesses
Fukushima Daiichi (2011)
Earthquake followed by tsunami caused nuclear power plant to meltdown and cause exposure to millions.
LD 50/30 & LD 50/60
Dose to kill 50% of a population within 30or 60days after exposure.
50/60 used for humans due to slower recovery rate and inaccurate results if only 30 days given to determine whether or not death will occur.
A whole body dose of 300-400 rads is said to be the
Lethal dose generally requires for humans without medical intervention; the dose may be higher with medical intervention.
Radioactivity
An unstable nucleus emitting energy and/or particles in an effort to become stable. The energy is gamma radiation and the particles are alpha particles, protons, neutrons, and beta particles.
Doubling dose
Measures the effectiveness of radiation in causing mutations.
- measures the radiation dose that causes the number of spontaneous mutations in a given generation to increase by two (doubling)
Doubling dose is estimated to be a mean dose of
156 rem and was determined from the Japan bomb survivors.
