1 / 73

Chemical Burns & Radiation Injuries

Chemical Burns & Radiation Injuries. Moritz Haager Dec. 04, 2003. Objectives. Approach to chemical burns Acids, alkali, HF Approach to radiation injuries Chemical & nuclear warfare agents. Perspective. > 65,000 chemicals in use; 60,000 new ones added yearly

limei
Download Presentation

Chemical Burns & Radiation Injuries

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chemical Burns & Radiation Injuries Moritz Haager Dec. 04, 2003

  2. Objectives • Approach to chemical burns • Acids, alkali, HF • Approach to radiation injuries • Chemical & nuclear warfare agents

  3. Perspective • > 65,000 chemicals in use; 60,000 new ones added yearly • 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

  4. Chemical Exposure • Dermal • Ocular • Inhalation • Ingestion • Systemic effects

  5. Determinants of injury severity • Chemical agent(s) • Duration of exposure / Penetration • Concentration & pH • Type of exposure

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

  7. General Approach • Prehospital • ED care • Post-ED care

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

  9. ED Care • Continue hydrotherapy • 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

  10. ED Care • Provide analgesia • Antibiotic prophylaxis & Tetanus prn • Identify & Tx Systemic Sx • Poison center consult to guide ongoing management

  11. Case 1 • 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

  12. Case 1 • MSDS sheet: • Ethylene glycol monobutyl ether, trisodium phosphate, nonoxynol-10 • pH 12.0

  13. Case 1 • Management • 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)

  14. Case 2 • 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

  15. Hydrofluoric Acid • 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 • 14.5% w/v  immediate Sx • 12% w/v  Sx w/in ~ 1hr • < 7% w/v  hrs before Sx develop

  16. Hydrofluoric Acid • Mechanism of Injury • Corrosive burn (H+ ions) • Chemical burn (Fluoride ions) • Penetrate tissue & form insoluble salts w/ Mg2+ & Ca2+ • Local (tissue destruction & necrosis) & systemic effects (hypocalcemia, hypomagnesemia, hyperkalemia)  arrhythmias • Concentrated HF (>50%) to 2.5% BSA has been fatal

  17. HF: Approach • Determine type & timing of exposure • Concentration & contact time • Rule out co-exposures • Rule out & monitor for systemic effects • Cardiac monitor • Trousseau’s & Chvostek’s signs, tetany • Lytes, Ca2+, Mg2+, ECG (QT) • Tx for local & systemic toxicity

  18. HF: Local Treatment • Copious irrigation 15-30 min • Persistent pain indicates deep penetration  need to eliminate Fluoride ion • Debride blisters & necrotic tissue • Fluoride chelation • Ocular burns • 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 • 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

  19. Fluoride Chelation: Calcium gluconate* • 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 Ca2+ • Wear glove for 24 hrs • SC infiltration of 5-10% Ca gluconate at 0.5 ml/cm2 • Consider regional anesthesia b/c severe pain • Intraarterial infusion • 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

  20. HF: Systemic Treatment • Evidence of hypocalcemia • 10 ml of 10% CaCL IV empirically • Repeat prn • Follow w/ serial lytes & ECG until normalizes

  21. Case 3 • 24 yo F grad student spilled phenol on her sleeve – brief rinse then continued to work • Presents feeling lightheaded, nauseated, and drowsy

  22. Phenol • 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

  23. Phenol: Treatment • Copious irrigation • 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

  24. Case 4 • 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

  25. Phosphorus • Waxy yellow solid; spontaneous ignition in air > 34oC • 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

  26. Phosphorus • Treatment • Submerse affected areas in COOL water, or cover in wet towels • Wash off w/ 5% Na bicarb & 3% CuSO4 in 1% hydroxyethyl cellulose solution • Phosphorus particles turn black • Phosphorus particles fluoresce under UV light

  27. Highlights • Formic acid • Bicarb for acidosis, may need HD or exchange transfusions for systemic toxicity • Anhydrous ammonia • Alkali burns • High danger of inhalational injury • Elemental metals • Na+ & K+ react w/ water to produce heat & H2 gas & OH- • Remove metal fragments & place in mineral oil or isopropyl alcohol (Na+) or terbutyl alcohol (K+)

  28. Part II: Chemical Warfare Agents

  29. Why we should know this • 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)

  30. Chemical Warfare Agents • Choking (pulmonary) agents • Chlorine, Phosgene • Vesicants (Blister agents) • Mustards, halogenated oximes • Nerve agents • G agents (Sarin, tabun, soman), VX • Cyanide agents • Improvised agents

  31. Vesicants • 3 subclasses • Mustards • 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

  32. Mustard Agents • Sulfur mustard = prototype • Designated H, or HD • 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

  33. Mustard: MOA • “Radiomimetic” • 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 • 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)

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

  35. Mustard: Treatment • Decontamination • 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

  36. Mustard: Treatment • No antidote; Tx is supportive • Bronchodilators, O2, steroids, bronchoscopy, mechanical ventilation • Analgesia • Tx cutaneous injuries like burns • Most pts recover completely • Factors associated w/ poor prognosis • Erythema >50% BSA • Dyspnea w/in 4-6 hrs of exposure • Respiratory failure • Bone marrow suppression

  37. Mustard Burns

  38. Mustard as a terror weapon • Difficult to detect, delayed onset • Potent, w/ significant morbidity • Easy to make, store, transport, & deliver • 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

  39. Halogenated Oximes • 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) • Enhances penetration of other agents • 2 proposed MOA’s • Direct injury due to corrosive effect & enzyme inhibition • Indirect injury due to alveolar macrophage activation & secondary pulmonary injury (delayed)

  40. CX: Clinical effects • 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

  41. CX: Treatment • No antidote • Decontaminate & Supportive Care • US military • M291 decontamination kits • Flush w/ large amounts of water

  42. Improvised Agents • Military & terrorist mission goals differ • 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 • 11 categories of diverse potential biological & chemical weapons • Underscores need for generalized approach & disaster planning

  43. General Guidelines • 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

  44. Part III: Radiation Injury

  45. Quiz • How large were the atomic (fission) bombs dropped on Hiroshima & Nagasaki? • 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? • 32, 000 = > 10,000 MT TNT

  46. Basics • Ionizing radiation • Short wavelength, high frequency • 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)

  47. Ionizing Radiation

  48. Units • SI Units • 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 • 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

  49. Real Life Examples • 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)

  50. Types of exposure • External radiation • 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

More Related