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)
- Determines need for decon
- http://www.msds.com/
- 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