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Radiation Emergencies
Charles Stewart MD EMDM
Fears
Media hype 1000’s will die Cancer Mutations
Special interest groups Terrorists
Real threats
Irradiation Contamination Incorporation
Real threats
Is the radiation exposure continuing? Irradiated patients pose no threat to the
EMS system or the provider. A patient who has an x-ray or CT does not
pose a threat to EMS Continued irradiation is a threat to the
provider Gamma emitter or x-ray device Establish a safe exposure
Real threats
Is the patient or scene contaminated Contaminated patients can hurt you Leave the contaminated scene.
Don’t bring anything with you.
Irradiation
The patient has been subjected to a high flux of gamma rays or neutrons This patient is not usually radioactive...
An exception occurs with high neutron flux Gold and some other materials absorb
neutrons and become radioactive
If irradiation continues, a tolerable dose for medical providers must be ascertained
Exposure....Irradiation
Dose depends on... Duration Distance Defenses (shielding)
Contamination
A radioactive material is on the skin, tools, or clothes.
This radioactive substance requires removal or it will continue to damage tissue. Decontamination
Incorporation
Radioactive material is inhaled, ingested, or contaminates an orifice or open wound.
The radioactive material can cause extensive cellular damage. Removal of the material may be an
interesting problem....
A few definitions
Ionizing radiation Electromagnetic radiation that
“knocks off” electrons is ionizing This happens at about 100 electron volts
Particulate radiation
Ionizing Radiation
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AlphaAlpha
BetaBeta
GammaGamma
1 m Concrete1 m Concrete
NeutronNeutron
Any radiation consisting of directly or indirectly ionizing
particles or photons.
Radiation
Alpha radiationA helium nucleus
(2 protons, 2 neutrons)
Easily stopped because the mass of the particle is so high
Radiation
Alpha radiationAlpha particles do not penetrate skin
If incorporated, alpha particle emitters will cause significant damage
Radiation
Beta radiationAn electron ejected at high speed
The charge and energy of the beta particle depends on the nuclear reaction that occurred.
Radiation
Beta radiationBeta emitters represent both an internal
and external threat to the patient (and to you!)
Radiation
Gamma radiation Exactly like X-rays
X-rays - from added external energy Gamma rays - from nuclear decay
Follows all laws of physics that pertain to light.
Inverse square law
Electromagnetic radiation (EMR) decreases with the square of the distance from the source
As distance increases by 2,intensity falls off by 4
This is why ‘distance’ is part of your protection.
Neutron radiation
Nuclear particles without a charge A product of nuclear fission Make other materials radioactive by
capture of the neutron and subsequent decay of the new isotope
Protons
Nuclear particles with a positive charge A product of nuclear fission
Van Allen belt Particle accelerators
Not a problem for EMS providers
Radiation measurement
“Flux measurement” Measures the flux of the moment ‘Geiger counter’ (beta and gamma survey) Scintillation counter (alpha survey)
Absorbed dose measurement Dosimeters
Radiation measurement
Dosimeters Film badge
Permanent record Fog with temperature and humidity
Ionization meter Sensitive to impact
Thermoluminescent dosimeter No permanent record
A few definitions....
RAD Radiation Absorbed Dose Deposition of 100 ergs of radiation per
gram of tissue.
A few definitions....
RRoentgen
Deposition of 87 ergs of radiation per gram of air.
A few definitions....
REMRoentgen Equivalent for Mammals
RBE x RAD dose = REM
(RBE = Relative Biological Effectiveness).
Maximum exposure permitted
Over age 18 5 REM / year for each year over 18
150 REM 1 time exposure in lifetime - ever.
25 REM 1 time exposure in a year.
Radiation bioeffects
History Perspective Acute effects Long term effects
Acute effects of radiation
Localized Skin erythema
Whole body Nausea and vomiting Malaise and fatigue Fever Hematologic changes
Biological effects
Clinical dosimeters Nausea and
vomiting Lymphocyte counts Skin erythema
Skin erythema
Varies with the type of radiation Akin to sunburn Rapid development may indicate a
severe exposure Not a particularly good dosimeter
Nausea and vomiting Somewhat dose related
Increased dose means quicker onset Absence of nausea implies minimal exposure
Severity of symptoms varies immensely Poor correlation with dose
Nausea and vomiting Nausea alone @ 5 or more hours - mild
exposure Vomiting @ 5 or more hours - mild exposure Vomiting @ 1-5 hours - moderate exposure Vomiting within 1 hour - severe exposure Vomiting within minutes - probably lethal
Lymphocyte count
Best biological dosimeter
< 500 lymphs/cc @ 48 hours is BAD
> 1200 lymphs/cc @ 48 hours is good.
Lymphocyte count
Lymphs/cc @ 48 hours 1500 or more - good prognosis 1000 - 1500 - moderate exposure 500 - 1000 - severe exposure 100 - 500 - very severe exposure less than 100 - uniformly lethal
Biological effects Whole body exposure
Mild exposure Hematopoietic syndrome GI syndrome Neurovascular syndrome
Mild exposure
Less than 200 rads Symptoms
Nausea and vomiting Possible hair loss
Prognosis - excellent Use contraception for 6 months
Hematopoietic syndrome
200 - 1000 rads Symptoms
Nausea and vomiting Diarrhea Pancytopenia Bone marrow suppression
Prognosis - good to poor
Gastrointestinal syndrome
1000 to 5000 rads Symptoms
Intractable nausea and vomiting Bowel necrosis Bone marrow suppression
Prognosis - poor
Neurovascular syndrome
5000+ rads Symptoms
Prodromal nausea and vomiting Rapid onset
Listlessness Tremors and ataxia Convulsions
Prognosis - hopeless
Where can we intervene.... Intermediate
exposure High level exposure
Radiation exposure treatment
No acute therapy Some pre-exposure treatment available
Radiation injury team concept Protection from infection Control of bleeding Supportive therapy
Intermediate Exposure
100 - 400 rads 5-50% death (untreated)
Bone marrow suppression Nausea, vomiting and diarrhea
Treatment helpful
High level exposure
400- 1000 rads Combination of GI and hematologic
syndromes Maximum lifesaving effort required
About 1 week to arrange the consults Laminar airflow “clean” rooms Marrow transplant
Long term effects
Cataracts Shortened life span Genetic effects Cancers
Leukemia Bone cancer (incorporation) Lung cancer (incorporation)
Long term effects
Dose related The minimum dose has not been
established Lower incidence of disease ?? Lowered resistance to infection
Exposure....
Measure the type and amount of the radioactive source.
If the source cannot be shielded or removed, then the allowable radiation exposure times must be calculated.
Decontamination
Starts at the scene Treat patient first
Medical therapy Remove contamination Wash patient
Decontamination Contamination can
be reduced remarkably by simply removing the clothing
Decontamination preparation
Disposable equipment Makeshift ambulances Litters and gurneys
Nondisposable equipment Cover all equipment with plastic Remove everything you can Don’t use expensive vehicles
Decontamination preparation
Establish a secured area Controlled access ? Cover with plastic sheeting Showers with a holding tank No “dirt” to leave the area
Decontamination agents
Soap and water Phosphate detergents
Tide EDTA or DPTA Potassium permanganate and sodium
bisulfate
Establish protocols
Train Train Train
Treat the patient first
Keep in mind that the patient is not radioactive...
You have to protect yourself from contamination not from the patient.
PROTECT yourself
Wear a dosimeter Dosimeters are not protective! They just tell you how much you got.
Distance
Increasing distance will decrease the dose by a factor calculated by the inverse square law
Decontamination
Estimates The amount remaining The amount removed
Save all fluids/stools/tissues If the patient excretes it, uses it, or loses
it... save it.
Decontamination
Flush... don’t scrub Scrubbing damages the skin
May use soap or decontamination solutions
Decontaminate highest radiation areas first.... if possible
Decontamination
May be augmented by... Prevention of uptake Enhancement of excretion
Check with your friendly radiation biophysicist for further details! Chelation Blocking Isotope dilution
Decontamination
Hair Shower Cut Do not shave
Decontamination
After decontamination.... Bag it. Patient clothing Dressing materials Metal items Tools
Label: Radioactive / do not discard
Decontamination
Staff Shower Fresh clothing Monitor for contamination
Special problems
Wounds Inhalation Ingestion / splash
Wounds
Cover with a self-adhesive surgical drape Prevents recurrent contamination
Then decontaminate / irrigate Surgical debridement
Inhalation
Half will be returned to pharynx Do not swallow
Save sputum ?? lung lavage
Ingestion / splash
Irrigate Mouth Eyes Ears ? Genitalia
Save the irrigation for analysis
Prophylaxis
Evacuation from area Agents to decrease uptake
Iodine Fluids ?? depends on contaminants
Prophylaxis
For radioactive iodine contamination a stable isotope of iodine is administered... SSKI
For radioactive tritium, a stable isotope of hydrogen is used... water
Prophylaxis
Chelating agents may be used if the patient has internal contamination with any of the transuranic elements Plutonium, uranium, neptunium,
americium.. ect.
Exposure protective zones
Electromagnetic PulseSeen with nuclear weapons
Effects ALL unshielded electronics
May render computers unusableAuto ignition
CT
Monitoring devices
Phones, radios and other communications
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Electromagnetic Pulse
Operation ‘Starfish Prime’ 1962Killed power in Hawaii
800 miles away
Worst with airburst > 30,000 feetStill bad with ground burst
Needs to be studied.Faraday cage may be sufficient
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