radiation emergencies charles stewart md emdm. fears n media hype n 1000’s will die n cancer n...

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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