Hazmat exposure

Background

• Definition - exposure to hazardous materials causing local/systemic toxicity

Types of Injury

• Acids
  • Cause coagulation necrosis which causes an eschar which often limits damage to deeper tissue
• Alkalis
  • Cause liquefaction necrosis that penetrates into deeper tissue
• Other mechanisms: oxidation, protein denaturation, cellular dehydration, local ischemia

Resources

• Resources to determine what is in the offending agent:
  • Poison control (800 222-1222)
  • Material Safety Data Sheet (MSDS)
    • Determines need for decon
  • Chemical Transportation Emergency Center (Chemtrec) Emergency Telephone Number: (800) 424-9300
    • Interntational and Maritime Telephone Number (collect calls accetped): +1 (703) 527-3887
  • TOXNET

Clinical Features

History

• Route/duration of exposure
• Often exposure in household, industry, agriculture, or terrorism
• Identifying the chemical is paramount

Exam

• Skin
  • Often appears deceptively normal initially
  • Look for visible remaining liquid/powder on skin

• Membranes
  • Potential for airway compromise
  • Inspect eyes/nasopharynx/cornea if indicated

• Pulm
  • Bronchospam/cough/pulmonary edema/cough

• Systemic sigs
  • altered mental status, seizures, tachy/brady dysrhythmias, hypo/hyper-tensive, GI sx, electrolyte abnormalitiyes, carboxyhemoglobinemia/methemoglobinemia, cyanide tox, toxidromic constellation of signs (e.g. cholinergic)

Evaluation

• Work up based on chemical culprit
• POC glucose
• BMP
• Calcium
• Magnesium
• Phosphorus
• LFTs
• VBG - concern for metabolic acidosis, carboxyhemoglobinemias, methemoglobinemias
• CXR - concern for pulmonary edema

Management

Logistics

• Establish Hazmat Plan
  • Affected patients need to stay in designated hot zones until decontaminated (staff can be injured secondary contamination inhalation of volatile gases)
  • Patients may arrive by EMS, private vehicle, walk ins
  • Establish security perimeter to enforce hot zone

• Protect yourself and staff
• Personal chemical protective equipment:
  • Level A: Positive-pressure self-contained breathing apparatus (SCBA), fully encapsulated chemical-resistant suit, double chemical-resistant gloves, chemical-resistant boots, and airtight seals between suit, gloves, boots
  • Level B: SCBA, nonencapsulated chemical suit, double gloves, boots
  • Level C: Air-purification device, suit, gloves, boots
  • Level D: Common work clothes

Decontamination

• Prehospital/In decon areas:
  • Hydrotherapy - irrigate skin and ocular burns immediately and continuously (>15 min)
    • Contraindicated only for elemental metals (Na, K)
  • Can allow patient to wash themselves if limited staff with protective gear
  • Dispose of all clothes/bandages/IVs

Management

• Aggressive supportive care, analgesia
• Antidotes if available
• Pulmonary involvement
  • O2, albuterol, intubate

Specific Conditions

• Chemical burns
  • Strong alkali, needs irrigation for hours
  • IVF 3cc/kg/TBSA, 1/2 given in first 8 hours
  • Hydrofluoric acid burn
    • Calcium gluconate via topic gel (10ml 10% sol'n applied topically), SC, or intra-arterial
    • IV calcium gluconate and magnesium for systemic toxicity
  • Phenol burns
    • Polyethylene glycol 300 +/- isopropyl alcohol to remove phenol from skin
  • Nitrites
    • Concern for Methemoglobinemia
    • Treat levels >30% with HF O2 and IV methylene blue (1-2mg/kg slow IV, not recommended for <6 y/o, >6 y/o 1mg/kg IV/IM)
  • Cyanide
    • Hydroxocobalamin (5mg IV /5 min, repeat once)
    • Elemental metals (Na or K)
    • Water is contraindicated
    • Cover with oil under substance can be debrided from skin

Disposition

• Transfer to burn center if criteria met
• Admit if systemic symptoms or airway concern
• Consider discharge of patients in consultation with poison control and/or after period of observation as needed

See Also

• Caustic burns
• Toxicology (Main)
• Weapon of mass destruction

External Links

• Material Safety Data Sheet (MSDS)
• TOXNET

References

Authors

Trevor C. Wilson, Neil Young, Ross Donaldson, Jonathan Warren