Rosen & Barkin's 5-Minute Emergency Medicine Consult (658 page)

• Irritant gas exposure
  
• Asphyxiant gas exposure
  
• Cardiogenic pulmonary edema
  
• COPD exacerbation
  
• Asthma exacerbation
  
• Pneumonia
  

TREATMENT

• 100% oxygen by face mask
  
• Intubation for patients with agonal breathing
  
• Rapid transport to ED for those with stridor:
  
  • May need advanced airway management
    
• Albuterol nebulizer therapy for bronchospasm
  

• 100% oxygen via face mask
  
• Intubation:
  
  • Respiratory distress
    
• Drooling
  
• Stridor:
  
  • Refractory hypoxia
    
  • CNS depression
    
  • Significant facial/upper airway burns
    
• Establish IV access.
  

• Inhaled or nebulized albuterol as needed for bronchospasm
  
• Corticosteroids as needed for patients with history of asthma or COPD
  
• Intubated patients:
  
  • Low endotracheal tube cuff pressure
    
  • Frequent suctioning
    
  • Positive end-expiratory pressure
    
• If indicated, treat for carbon monoxide toxicity:
  
  • 100% oxygen
    
  • Hyperbaric oxygen in appropriate cases when available
    
• If indicated, treat for cyanide toxicity:
  
  • 100% oxygen
    
  • Hydroxocobalamin (preferred)
    
  • If only older nitrite-containing cyanide antidote kit is available
    
  • Sodium nitrite should be used with caution in cases of significant carbon monoxide exposure
    
  • Sodium thiosulfate can be used safely with CO exposures
    

• Albuterol nebulization: 2.5–5 mg in 2.5 mL of normal saline q20min:
  
  • Alternatively, 15 mg nebulizer treatment continuous over 1 hr
    
• Methylprednisolone 40 mg IV (peds: 1–2 mg/kg)
  
• Prednisone: 40–60 mg PO (peds: 1–2 mg/kg)
  
• Sodium thiosulfate 12.5 g (50 mL of 25% solution) slow IV infusion (peds: 412.5 mg/kg or 1.65 mL/kg of 25% solution)
  
• Hydroxocobalamin 5 g IV infused over 15 min (peds: 70 mg/kg)
  

FOLLOW-UP

• Intubated
  
• Significant associated burns
  
• Persistent dyspnea, hoarseness, odynophagia, carbonaceous sputum
  
• Persistent cough
  
• Asthma/COPD with bronchospasm
  
• Significant carbon monoxide or cyanide exposure
  
• Comorbid medical illnesses
  

• Minimal exposure history
  
• Asymptomatic
  
• Significant exposure history, asymptomatic after 4–6 hr observation
  

• In cases of significant associated burn injuries, transfer to burn facility as appropriate.
  
• In cases of significant carbon monoxide toxicity, transfer to hyperbaric oxygen facility as appropriate.
  

Burn follow-up for patients with associated burns.

• In suspected cases of cyanide exposure, do not wait for the level before initiating therapy.
  
• Order carboxyhemoglobin to evaluate for potential carbon monoxide exposure.
  

• Peck MD. Structure fires, smoke production, and smoke alarms.
  J Burn Care Res
  . 2011;32(5):511–518.
  
• Rehberg S, Maybauer MO, Enkhbaatar P, et al. Pathophysiology, management and treatment of smoke inhalation injury.
  Expert Rev Respir Med
  . 2009;3(3):283–297.
  
• Toon MH, Maybauer MO, Greenwood JE, et al. Management of acute smoke inhalation injury.
  Crit Care Resusc
  . 2010;12(1):53–61.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Carbon Monoxide
  
• Cyanide
  
• Hyperbaric Oxygen
  

CODES

• 506.2 Upper respiratory inflammation due to fumes and vapors
  
• 508.2 Respiratory conditions due to smoke inhalation
  
• 947.1 Burn of larynx, trachea, and lung
  

BASICS

• Pit viper venom:
  
  • Mixture of proteolytic enzymes and thrombin-like esterases:
    
    • Enzymes cause local muscle and subcutaneous tissue necrosis.
      
    • Esterases have defibrinating anticoagulant effect, leading to venom-induced consumption coagulopathy (VICC) in severe envenomations.
      
• Bite location:
  
  • Extremity bites most common
    
  • Head, neck, or trunk bites more severe than bite on extremities
    
• Severe envenomation:
  
  • Direct bite into artery or vein
    
  • Neurotoxic envenomations
    
• Bite mark significance:
  
  • Pit viper bite: Classically includes 1 or 2 puncture marks
    
  • Nonvenomous snakes and elapids: Horseshoe-shaped row of multiple teeth marks
    
• 25% of all pit viper bites are dry and do not result in envenomation.
  

• Pit vipers (Crotalinae):
  
  • Account for 95% of all envenomations
    
  • Rattlesnakes, cottonmouths, and copperheads
    
• Coral snakes (Elapidae):
  
  • Neurotoxic
    
  • Western coral snakes, found in Arizona and New Mexico
    
  • More venomous eastern coral snakes, found in Carolinas and Gulf states
    

Occur in zoos or in owners of exotic snakes

• 30% of all snakebites involve patients younger than 20 yr. 12% of all snakebites are 9 yr or younger.
  
• Because of their low body weight, smaller children and infants are more vulnerable to severe envenomation with systemic symptoms.
  

DIAGNOSIS

• Local (Crotaline):
  
  • Classic skin changes:
    
    • 1 or 2 puncture wounds
      
    • Pain and swelling at site
      
  • Swelling and edema of involved extremity:
    
    • Within 1 hr in severe envenomations
      
    • Tender proximal lymph nodes
      
  • Ecchymosis, petechiae, and hemorrhagic vesicles develop within several hours.
    
• Systemic (Crotaline):
  
  • Weakness, dizziness
    
  • Diaphoresis
    
  • Nausea
    
  • Scalp paresthesias
    
  • Periorbital fasciculations
    
  • Metallic taste
    
  • Severe bites can lead to:
    
    • Coagulopathy (VICC)
      
    • Hypotension
      
    • Pulmonary edema
      
    • Hematuria
      
    • Rhabdomyolysis
      
    • Renal failure
      
    • Cardiac dysfunction
      
  • Potential elevated compartment pressure in involved extremity
    
• Symptoms (Crotaline):
  
  • Primarily neurotoxic, leading to weakness, diplopia, confusion, delayed respiratory depression:
    
    • Local effects may be deceivingly minimal.