Moritz Haager
Dec. 04, 2003

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Approach to chemical burns
 Acids, alkali, HF
Approach to radiation injuries
Chemical & nuclear warfare agents

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 > 65,000 chemicals in use; 60,000 new ones added yearly
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Impossible to know each of these
Health effects mostly unknown
Important to have a general approach
Know the common agents
Important to make use of MSDS sheets & Poison Centers

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Dermal
Ocular
Inhalation
Ingestion
Systemic effects

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Chemical agent(s)
Duration of exposure / Penetration
Concentration & pH
Type of exposure

 Acids
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Coagulation necrosis
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Coagulate proteins forming barrier to further penetration
More superficial burns
Tissues have intrinsic acid buffering capacity
Strong acids have pH < 2
 Alkali
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Liquefaction necrosis
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Combine w/ proteins & saponify lipids
Deep ongoing tissue penetration
Difficult to access with hydrotherapy
Strong bases have pH > 11

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Prehospital
ED care
Post-ED care

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Scene safety
Remove pt from danger
ABC’s & primary survey
Immediate decontamination
 Remove contaminated clothing
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Brush off dry chemicals first
Copious low pressure irrigation
Identify agent(s) & obtain MSDS sheets if possible

 Continue hydrotherapy
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Strong acids: 2-3 hrs
Strong alkali: 12 hrs or more!!
Copious amounts to offset any exothermic reaction & maximally dilute
Low pressure to prevent spray contamination

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Provide analgesia
Antibiotic prophylaxis & Tetanus prn
Identify & Tx Systemic Sx
Poison center consult to guide ongoing management

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12 mo M spilled “Resolve” multi-purpose cleaner on his leg
Mom did not notice for ~15 min
Presents w/ obvious erythema and areas of excoriation on R ant leg & R wrist
Also lips red & cracked
No stridor, wheeze, or resp distress
Vitals normal, rest of exam normal

 MSDS sheet:
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Ethylene glycol monobutyl ether, trisodium phosphate, nonoxynol-10 pH 12.0

 Management
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Flush, flush, flush
Observe cautiously for airway involvement
IV placed for analgesia & possible airway management
Lytes incl. Mg, Ca
PADIS consult (prior to obtaining MSDS)

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17 yo M comes in c/o severe pain in all digits of his hand worsening since y/d
Cleaning rusty bicycle chain with rust cleaner y/d
Indurated, tough, whitish finger tips

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Found in rust cleaners, metal cleaners
Also used for glass etching & electronics manufacturing
Dilute solutions penetrate deeply & cause delayed Sx onset & more severe burn; pain can last days
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14.5% w/v  immediate Sx
12% w/v  Sx w/in ~ 1hr
< 7% w/v  hrs before Sx develop

 Mechanism of Injury
 Corrosive burn (H + ions)
 Chemical burn (Fluoride ions)
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Penetrate tissue & form insoluble salts w/
Mg 2+ & Ca 2+
Local (tissue destruction & necrosis) & systemic effects (hypocalcemia, hypomagnesemia, hyperkalemia)  arrhythmias
Concentrated HF (>50%) to 2.5% BSA has been fatal

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Determine type & timing of exposure
Concentration & contact time
Rule out co-exposures
Rule out & monitor for systemic effects
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Cardiac monitor
Trousseau’s & Chvostek’s signs, tetany
Lytes, Ca 2+ , Mg 2+ , ECG (QT)
Tx for local & systemic toxicity

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Copious irrigation 15-30 min
 Persistent pain indicates deep penetration  need to eliminate
Fluoride ion
Debride blisters & necrotic tissue
Fluoride chelation
Ocular burns
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 sterile water or saline irrigation (may need local anesthetic drops)
Persistent pain  1% calcium gluconate irrigation (10% solution in 10x volume of NS)
Inhalation burns
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100% oxygen by mask, 2.5% calcium gluconate by nebulizer
Watch for pulmonary edema
Ingestions (Usually fatal)
 Consider gastric lavage with calcium chloride (i.e., 20 mmol calcium in
1000 cc NS) if early presentation
 Intubate prior to lavage

*
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Topical gel
 2.5% = 10% Ca gluconate in 3x volume of muco or KY jelly e.g. 25 ml in 75 ml muco) in latex glove – persistent pain after 30 min indicates need for SC or intraarterial Ca 2+
 Wear glove for 24 hrs
SC infiltration of 5-10% Ca gluconate at 0.5 ml/cm 2
 Consider regional anesthesia b/c severe pain
Intraarterial infusion
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10 ml 10% Ca gluconate in 50 ml D5W over 4 hrs into radial or ulnar artery; repeat if pain persists / returns within 4 hrs
20 ml of 20% Ca gluconate in 80 ml D5W; repeat in 12 hrs prn
 Watch for pain, arterial spasm, thrombosis  tissue necrosis and digit loss have occurred following extravasation of calcium salts
 *NB: KCL is more irritating & damaging therefore use Ca gluconate

 Evidence of hypocalcemia
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10 ml of 10% CaCL IV empirically
Repeat prn
Follow w/ serial lytes & ECG until normalizes

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24 yo F grad student spilled phenol on her sleeve – brief rinse then continued to work
Presents feeling lightheaded, nauseated, and drowsy

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Aromatic acidic alcohol
Plasticizer, antiseptic, used for DNA extraction in labs
Dilute solutions less likely to cause papillary necrosis therefore tend to penetrate more quickly
Locally causes acidic burn
Systemic absorption leads to CNS depression  coma & resp arrest, as well as hypotension, metabolic acidosis, hypothermia

 Copious irrigation
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Polyethylene glycol 200 or 400 or isopropyl alcohol most effective, but can use water (just use LOTS)
PEG can be used for ocular exposures
Physiologic support for systemic Sx
Tx in well ventilated room

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You are w/ MSF in the jungles of Cambodia
A young boy is brought in w/ severe burns after a friend stepped on unexploded ordinance which then blew up in a brilliant white flash killing his friend and showering him with burning debris

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Waxy yellow solid; spontaneous ignition in air > 34 o C
Used in munitions, insecticides, rodenticides, & pesticides
Will continue to burn on skin
 Firebombing of Dresden in WWII
Primarily causes thermal burns
Systemic effects metabolic in nature
 Hypocalcemia, hyperphosphatemia  bradyarrhythmias

 Treatment
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Submerse affected areas in COOL water, or cover in wet towels
Wash off w/ 5% Na bicarb & 3% CuSO
4 in 1% hydroxyethyl cellulose solution
 Phosphorus particles turn black
Phosphorus particles fluoresce under UV light

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Formic acid
 Bicarb for acidosis, may need HD or exchange transfusions for systemic toxicity
Anhydrous ammonia
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Alkali burns
High danger of inhalational injury
Elemental metals
 Na + & K + react w/ water to produce heat & H
2 gas & OH -
 Remove metal fragments & place in mineral oil or isopropyl alcohol (Na + ) or terbutyl alcohol (K + )

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Increased potential for terrorist use
Relatively easy to make or obtain
 Most are simple derivatives of precursor compounds in manufacture of plastics, pesticides, & fabrics
Non-traditional chemical agents can be used as weapons in the right setting
 Bhopal – methyl isocynate (2000 dead)

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Choking (pulmonary) agents
 Chlorine, Phosgene
Vesicants (Blister agents)
 Mustards, halogenated oximes
Nerve agents
 G agents (Sarin, tabun, soman), VX
Cyanide agents
Improvised agents

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3 subclasses
 Mustards
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Arsenicals
Halogented oximes
Produce cutaneous, ocular, mucous membrane, & pulmonary burns
Less lethal (primarily kill via pulmonary involvement) but highly morbid
Effects tend to be delayed
Easy to manufacture or obtain

 Sulfur mustard = prototype
 Designated H, or HD
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Easy & inexpensive to produce
Most dangerous agent in WWI
Low lethality (1-3%) but high morbidity
Most recent use by Iraq in Iran-Iraq war
Low volatility, high persistence
Delayed Sx onset (may take up to 12 hrs)  prolonged exposure

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“Radiomimetic”
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Contaminates environment
Penetrates clothing & skin easily w/o visible or perceptible effects
Precise cellular action unknown but acts similar to alkylating agents
 Inhibits glycolysis  cellular death
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Primary tissue irritant
DNA, RNA, & protein damage
 Mutagenic, carcinogenic, teratogenic
Poorly soluble in water; dissolves readily in skin oils
 Predilection for moist areas of body
 (eyes > resp tract > scrotum > face > anus)

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Ocular
 Corneal ulceration, iritis, blindness
Respiratory
 URT irritation, chemical pneumonitis respiratory failure, death
GI
 N &V
Hematologic
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Bone marrow suppression, pancytopenia
CVS
 CV collapse, shock, death
Immune system
 Immunosupression, sepsis
Dermal
 Cutaneous burns

 Decontamination
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Prior to entry into medical facility
Protect workers
Remove all clothing (contaminated)
0.5% hypochlorite (bleach) irrigation
Debride & decontaminate bullae
US Military kits:
 2 sets of paper towels soaked with phenol & hydroxide followed by chloramine
Adsorbents (flour, talcum powder)
Water less ideal b/c poor solubility but may use in large amounts if nothing else available
Ocular exposures should be rinsed w/ 2.5% thiosulfate sol’n & then topical abx, & cycloplegics  optho consult

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 No antidote; Tx is supportive
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Bronchodilators, O
2
, steroids, bronchoscopy, mechanical ventilation
Analgesia
Tx cutaneous injuries like burns
Most pts recover completely
Factors associated w/ poor prognosis
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Erythema >50% BSA
Dyspnea w/in 4-6 hrs of exposure
Respiratory failure
 Bone marrow suppression

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Difficult to detect, delayed onset
Potent, w/ significant morbidity
Easy to make, store, transport, & deliver
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Bombs, aerosol, vapour, rockets, canisters
9 openly documented manufacturing methods that can be done with high school lab supplies in someone's basement (the MDA of terrorism if you will)
Cheap
Persistent; difficult to clean up
Sig. experience in mid-east due to use in Iran-Iraq war

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Phosgene oxime (CX, dichloroform oxime)
Also known as urticariants or nettle gases
Fair water solubility
Immediate Sx onset; unpleasant odor
No confirmed battlefield use
Penetrates clothing, rubber, & skin rapidly (sec’s)
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Enhances penetration of other agents
2 proposed MOA’s
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Direct injury due to corrosive effect & enzyme inhibition
Indirect injury due to alveolar macrophage activation & secondary pulmonary injury (delayed)

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Immediate effects & absorption
Mild irritation  severe pain
Skin has grayish blanched appearance & surrounding erythema which can go on to blister or form hives & pruritus
Turns brown & into dark eschar over 24h – 1 wk
Also immediate conjunctivitis & ocular pain

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No antidote
Decontaminate & Supportive Care
 US military
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M291 decontamination kits
Flush w/ large amounts of water

 Military & terrorist mission goals differ
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Many chemical deemed poor for warfare more than appropriate for terror attacks
Thousands of commercial compounds can potentially become weapons
 E.g. 911 – jetliners turned into bombs
CDC threat list
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11 categories of diverse potential biological & chemical weapons
Underscores need for generalized approach & disaster planning

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Prehospital decontamination ideal
 Assume decontamination has NOT occurred
Protective clothing
 No PPC suit can protect against all agents, but Level A suits are best
Latex gloves useless; nitrile much better

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How large were the atomic (fission) bombs dropped on Hiroshima &
Nagasaki?
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Equivalent to 12,500 & 20,000 tons of TNT respectively
66, 000 people instantly died & 69,000 injured in Hiroshima
Blast radius was 3 miles in diameter
What are modern (fusion) thermonuclear warhead yields?
 In the mega ton range (largest ever detonated 100 MT)
What was is the lethal radius of a 10 KT weapon? A 20 MT weapon?
 3 miles vs. 35 miles
How many nuclear devices have been detonated?
 A: > 2000 tests, >500 above ground
How many nuclear warheads were held at the height of the Cold
War?
 Over 69,000 in 1985
How many now?
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32, 000 = > 10,000 MT TNT

 Ionizing radiation
 Short wavelength, high frequency
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High energy: 1 billion x that of non-ionizing
UV, X, & γ rays; α & β particles; neutrons
Released by unstable atomic particle decay = radioactivity
Ability to knock electrons out of orbit of other atoms (ionize them)

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SI Units
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Sievert (Sv) = exposed dose or dose equivalent
 1 Sv = 1 Gy
Gray (Gy) = absorbed dose
 1 Gy = 1 joule energy absorbed / Kg tissue
Becquerel (Bq) = activity
Older Units
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Rem = radiation equivalent man
 1 rem = 0.01 Gy
Rad = radiation absorbed dose
 1 rad = 0.01 Sv
Roentgen (R) = exposure
 1 R = 0.01 Gy
Curie (Ci) = activity
 1 Bq = 27 pCi

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1 CXR = 0.02 mSv
Background radiation ~3 mSv / yr (150
CXR’s)
AXR 1.5 mSv (75 CXR’s)
Abdominal CT 6 – 8 mSv (300-400 CXR’s)
Background radiation in affected parts of
Belarus, Ukraine, & Russia 6 -11 mSv / yr
(300 – 550 CXR’s)
Firefighters in Chernobyl 0.7 – 13 Sv
(35,000 – 650,000 CXR’s)

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External radiation
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E.g. X-rays
Only neutrons can produce radioactivity
 I.e. a pt exposed to other radiation is NOT radioactive & poses no risk to others
External contamination
 E.g. radioactive spill in lab
Incorporation & internal contamination
 Ingestion, inhalation, open wounds

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Direct effects
 Ionization & damage of molecules (e.g. cross-linking of DNA)
 100 mGy -- get ssDNA damage (reparable)
 0.5 - 5 Gy -- dsDNA damage (irreparable)
Indirect effects
 Ionization of H
2
O to H
2
O + radical  decays to free radicals which react with & damage other molecules

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Dose rate
 How fast a given dose is delivered
Energy
Total dose
Total vs. partial exposure
Tissue(s) exposed (radiosensitivity)

 Three laws of radiosensitivity
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Bergonie & Tribondeau, 1906
Varies directly w/ rate of cell proliferation
Varies directly w/ # of future divisions
Varies inversely w/ degree of morphologic & functional differentiation
 Lymphocyte is the exception = most radiation-sensitive cell in body

 Deterministic (nonstochastic)
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Threshold dose
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Effect is not seen if threshold dose is not exceeded
See dose-response curve
Effects manifest w/in mins – wks
 E.g. ARS
 Stochastic
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No threshold dose
 Controversial
Not all exposed individuals manifest the effect
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No clear dose-response curve
Effect less pronounced at high exposures
E.g. = radiationinduced carcinogenesis

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Nuclear device detonation
 Military use (e.g. Hiroshima, Nagasaki)
 Terrorist use
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“Dirty” bombs
 RDD (radiation dispersal device)
Industrial accidents / spills
 Chernobyl, Three mile island
Medical & Research
 Radiation Tx, Radioisotope spills

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Blast & thermal effects
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Most significant injuries acutely therefore Tx conventional injuries first
Megaton yield weapons  lethal radius from blast & thermal effect larger than that for radiation effect Radiation effects
Radiation effects
 Intense neutron & gamma ray release
Fallout
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Radioactive particulate matter (soil etc) following significant radiation release or nuclear explosion
Can poison food chain & render area uninhabitable for yrs
Can travel great distances (e.g. Chernobyl)

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Most common cause of death in 1 st 60d following external whole body irradiation
Divided into sequential subsyndromes:
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Hematopoietic (1- 5 Gy)
Gastrointestinal (6-30 Gy)
CVS / CNS (>30 Gy)
4 separate stages
 Prodromal, latent, manifest illness, recovery
Timing of stages & subsyndromes inversely related to dose received
LD
50 for radiation is estimated to be 4.1 Gy (95%CI
2.55 – 5.5)

Dose
(Gy)
0.5 – 2
2.1 – 3.5
3.6 – 5.5
> 5.6
Onset
(h)
≥ 6
2 – 6
1 – 2
Mins – 1
Duration
(h)
< 24
Latency
≥ 3 wks
12 – 24 2 – 3 wks
24 1 – 2.5 wks
48 2 – 4 days

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1 o Sx are N &V, diarrhea (occ bloody)
Anorexia, weakness, fatigability
Time of onset inversely related to dose
Duration & severity directly related to dose
 Mild Sx occurring ≥ 2 hrs post-exposure
& lasting < 24 h usually imply dose < 2
Gy

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Duration inversely related to dose
 Hrs - wks
May be asymptomatic w/ lower doses
More at risk for infection
Delayed wound healing
Critical to monitor closely

 Hematopoetic (1 – 5 Gy)
 Delayed onset of pancytopenia due to stem cell irradiation
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Death due to sepsis +/- hemorrhage
Takes mos – yrs to recover
Lymphocyte & platelet counts can be used to estimate exposure & guide mgmt
Lymphocyte count 24-48 h post-exposure
(x1000 / mm 3)
3.0
1.2 – 3.0
0.4 – 1.2
0.1 -0.4
< 0.1
Estimated Dose (Gy)
≤ 0.25
1 – 2
2 – 3.5
3.5 – 5.5
> 5.5

 Gastrointestinal (6 -30 Gy)
 GI stem cell death  breakdown of intestinal mucosa w/ hemorrhages, fluid
& electrolyte shifts, & bacterial translocation
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Sepsis
Malnutrition
Paralytic ileus
Hypovolemia & electrolyte imbalances

 CVS / CNS (> 30 Gy)
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Direct damage to CNS & CVS tissues
C/o burning pain of skin w/in mins
Pyrexia, ataxia, elevated ICP & coma, hypotension w/in mins - hrs

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Skin burns
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Transient erythema w/in hrs
Secondary erythema w/in 5 – 21d
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Timing inversely proportional to dose
Low doses  progress to dry desquamation
High doses  wet epidermitis & blisters
Tx same as thermal burns +/- steroid creams
Acute radiation pulmonitis
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Severe dyspnea, “thundering” creps
 High dose exposure – almost universally fatal
Psychological Impact
Chronic Health effects

 Triage
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Radiation injury unlikely
 Absence of prodromal N & V & D
Probable radiation injury (survivable)
 Group most likely to benefit from intensive medical care
Severe radiation injury (usually fatal)
 Analgesics, comfort measures

 External Decontamination
 Should occur ASAP & prehospital if possible
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Showering or washing w/ soap & water achieves
~95% decontamination
Debride & clean open wounds
Risk to medical personnel exposed to contaminated persons appears to be minimal
Monitor w/ whole body radiation counters,
Geiger counters, thyroid scanners & bioassay sampling

 Internal Decontamination
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Knowledge of radioisotope important to guide management
Decrease absorption
 Cathartics, SBL, charcoal, BAL for severe inhalation
Increase elimination
 Chelation
Block uptake / incorporation
 Antidotes E.g. potassium iodide (need to start w/in 12-
24h at latest)
Bioassay & Geiger counts on urine & feces to guide ongoing Tx

 Prussian blue
 Penicillamine
 Chlorthalidone
 Deimercaprol
 Deferoxamine
 Ca-EDTA
 Zn-DTPA
 Cesium
 Cu, Co, Ag, Pb, Hg
 Rubidium
 Polonium
 Iron
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Cd, Cr, Pb, Zn
All the weird ones ±
American names

 Medical Tx
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Largely supportive
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Symptomatic Tx
Infection control
Serial CBC’s
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Transfuse if plts < 20
CSF may be useful
Bone marrow transplant may be necessary
Any necessary surgery should occur either w/in
36 hrs; otherwise wait at least 3 mos
 Fibroblasts & osteoblasts radiosensitive -- impaired wound healing

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Stochastic effects
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Highly controversial topic
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While exposure to radiation appears to increase risk of CA, birth defects, and other health problems we still don’t know what a
“safe” dose is
Most people think risk of exposure is cumulative but even this is not clear-cut
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One very large single dose likely more harmful than same dose over long time period
Mutation rate in crops of contaminated regions in Europe 6x higher than elsewhere
Increased incidence of thyroid CA
Increased incidence of various CA’s in atomic bomb survivors & aftermath of Chernobyl w/ exposures > 50 - 100 mSv
Studied hindered by methodological flaws -- difficult to determine precise risk for an individual exposed to increased radiation