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)

Differential Diagnosis

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

External Links

References