Rosen & Barkin's 5-Minute Emergency Medicine Consult (313 page)

Hand Infections
http://emedicine.medscape.com/article/783011-overview

CODES

• 112.3 Candidiasis of skin and nails
  
• 681.02 Onychia and paronychia of finger
  
• 914.9 Other and unspecified superficial injury of hand(s) except finger(s) alone, infected
  

BASICS

• Hazmat refers to exposure to hazardous materials causing local or systemic toxicity.
  
• Pathophysiology:
  
  • Acids cause coagulation necrosis with eschar, usually limiting penetration to deeper tissue.
    
  • Alkalis cause liquefaction necrosis and soluble complexes that penetrate into deep tissues.
    
  • Damage also occurs through oxidation, protein denaturation, cellular dehydration, local ischemia, and by metabolic competition/inhibition.
    

• Hazardous materials are encountered in household, industry, agriculture, transportation accidents, and in criminal/terrorist activities.
  
• The toxicity of the materials relates to the particular substances and their effects.
  

DIAGNOSIS

• Skin:
  
  • Chemical burns; may appear deceptively mild initially
    
  • Visible liquid or powder on skin
    
  • Absorption through skin may cause systemic toxicity.
    
• Mucous membranes (eyes, nasopharynx; see Corneal Burn):
  
  • Ranges from subjective irritation to serious mucosal burns
    
  • Potential airway compromise
    
• Pulmonary:
  
  • Cough
    
  • Pleuritic chest pain
    
  • Bronchospasm
    
  • Dyspnea
    
  • Pulmonary edema (immediate or delayed)
    
• Systemic (after skin or pulmonary absorption):
  
  • Altered mental status
    
  • Seizures
    
  • Tachy/brady dysrhythmias
    
  • Hypotension/HTN
    
  • GI symptoms
    
  • Electrolyte disturbances
    
  • Carboxyhemoglobinemias and methemoglobinemias
    
  • Cyanide toxicity
    
  • Cholinergic syndrome (see Chemical Weapons Poisoning, Nerve Agents)
    

Elicit type, circumstances, and duration of exposure

• Attempt to identify substance using pre-hospital providers, Material Safety Data Sheet (MSDS), and
  Chem
  ical
  Tr
  ansportation
  E
  mergency
  C
  enter (Chemtrec).
  
• MSDS:
  
  • Identifies chemicals
    
  • Differentiates vapor vs. skin hazard
    
  • Determines need for decontamination
    
  • Limited treatment data
    
• Determine route and duration of exposure.
  
• Inhalation injury more likely in an enclosed space
  
• Determine toxicity using poison control; computerized databases, such as POISINDEX or TOXNET; or standard toxicology test.
  
• Observe as needed for systemic toxicity.
  

• Depends on substance
  
• Electrolytes, BUN, creatinine, and glucose levels
  
• LFTs
  
• Calcium level
  
• Magnesium level
  
• Phosphorus level
  
• Arterial blood gases:
  
  • Metabolic acidosis
    
  • Carboxyhemoglobinemias and methemoglobinemias
    
  • Respiratory failure
    

Chest radiograph for pulmonary edema

• Skin:
  
  • Hypersensitivity reaction
    
  • Thermal burns
    
• Pulmonary:
  
  • Pneumonia
    
  • Pulmonary embolism
    
  • Anaphylaxis
    
• Systemic:
  
  • Status epilepticus
    
  • Overdose
    
  • Psychiatric illness
    
  • Myocardial infarction
    

TREATMENT

• Recognize a HAZMAT situation:
  
  • Accident at industrial/agricultural site
    
  • Accident involving transport of hazardous materials
    
  • Suspected terrorist mass casualty incident
    
  • Cholinergic syndrome
    
  • Irritant mucous membrane symptoms
    
  • Chemical burns
    
• Protect yourself:
  
  • Approach from upwind.
    
  • Do not enter scene until safety of material is determined.
    
  • Use Level A protective gear if safety not established
    
  • Anyone able to walk and talk is minimally contaminated.
    
• 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
    
  • Identify substance:
    
    • Department of Transportation (DOT) placard, MSDS, shipping papers, hazard labels
      
    • If unsuccessful, call Chemtrec (1[800] 424-9300) to determine substance and toxicity.
      
    • Hazmat teams can do chemical testing.
      
• Determine toxicity and need for decontamination:
  
  • Poison control (1[800] 222-1222)
    
  • Chemtrec
    
• Decontaminate:
  
  • Hazmat team
    
• Treat:
  
  • Provide basic life support and advanced life support care as indicated.
    
  • Generally basic list support only in a “hot zone”
    
  • Irrigate skin and ocular burns immediately and continue until arrival at hospital.
    

• Protect ED personnel:
  
  • Secondary contamination can occur from dermal contact or through inhalation of volatile gases/particles.
    
• Keep patients outside in designated hot zones until decontaminated.
  
• When in doubt, decontaminate.
  
• Expect contaminated patients to arrive via emergency medical services or private vehicle.
  
• If treatment is required before/during decontamination:
  
  • Use minimum necessary staff in appropriate personal protection gear.
    
  • Focus on life- and limb-saving care only.
    
• Decontamination:
  
  • Security to enforce hot zone
    
  • Remove, label, and double-bag clothing (including contact lens).
    
  • Copious irrigation with soap and water for 10–15 min with special attention to obviously contaminated areas, wounds, and exposed eyes
    
  • Recapture water to prevent contamination of the sewer and downstream areas:
    
    • In an emergency or mass casualty situation, it is acceptable to let water drain into sewer.
      
  • Hydrotherapy:
    
    • Mainstay of therapy for chemical burns
      
    • Contraindicated only for elemental metals (sodium and potassium)
      
  • Allow patient to decontaminate himself or herself or use trained decontamination team.
    
  • Decontaminate children, dependent elderly, mentally/physically challenged and their appliances (e.g., wheelchairs) with caregivers
    
  • Gloves, masks, goggles, and disposable gowns provide some protection
    
  • Remove/replace bandages, tourniquets, airway adjuncts, IV sets
    
  • Retriage after decontamination.
    

• Provide supportive care as needed.
  
• Determine if antidotal treatment would be effective and available.
  
• Hazmat incidents provoke extreme fear:
  
  • Expect casualties suffering from collective hysteria.
    
  • Knowledge of toxicologic profile can exclude contamination in these patients.
    
• ED staff may become symptomatic even if chemical concentrations in the air are below toxic levels and may need to be escorted to fresh air.
  
• Chemical burns:
  
  • Irrigation should be started as soon as possible and, if owing to a strong alkali, may need to be continued for hours.
    
  • Aggressive fluid resuscitation with 2–4 mL/kg lactated Ringer solution per total burn surface area (TBSA) percent over 24 hr with 1/2 given over the 1st 8 hr
    
  • Pain control
    
• Pulmonary symptoms:
  
  • Bronchodilators, oxygen, intubation, and mechanical ventilation
    
• Selected special treatments:
  
  • Hydrofluoric acid burns:
    
    • Calcium gluconate via topical cutaneous gel, SC, or intra-arterial
      
    • For systemic toxicity: IV calcium gluconate and magnesium
      
  • Phenol burns:
    
    • Remove phenol from skin with polyethylene glycol 300 or 400 or with isopropyl alcohol.
      
  • Nitrates:
    
    • Ingested or extensive burns may cause methemoglobinemia.
      
    • Treat levels >30% with high-flow oxygen and IV methylene blue.
      
  • Elemental metals (sodium/potassium):
    
    • Water lavage is contraindicated and dangerous.
      
    • Cover with oil until substance can be débrided from skin.
      
  • Cyanide toxicity:
    
    • Hydroxocobalamin administration
      
  • Organophosphates/carbamate insecticides (see Chemical Weapons Poisoning)