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.

History

  • Route/duration of exposure
  • Often exposure in household, industry, agriculture, 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/pulm edema/cough
  • Systemic sigs
    • AMS, seizures, tachy/brady dysrhythmias, hypo/hyper-tensive, GI sx, electrolyte abnormalitiyes, carboxyhemoglobinemia/methemoglobinemia, cyanide tox, toxidromic constellation of signs (e.g. cholinergic)


Resources

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

Diagnostics

  • Work up based on chemical culprit
  • POC glucose
  • BMP Electrolytes, BUN, creatinine, and glucose levels *LFTs
  • Calcium
  • Magnesium
  • Phosphorus
  • ABG - concern for metabolic acidosis, carboxyhemoglobinemias, methemoglobinemias
  • CXR - concern for pum edema

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

Decon

  • 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
  • Antidote, if available
  • Pulm invovlement
    • O2, albuterol, intbuate

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% w/ 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 meet criteria)
  • Admit if systemic sx, airway concern
  • Could d/c pts in consultation with poison control after period of obs.

References

Schaider, Jeffrey. Rosen &Barkin's 5-Minute Emergent Medicine Consult