Background and Etiology

• Definition of Hydrocarbon: compounds composed predominantly of carbon and hydrogen
• Industrial and Commercial Sources of Hydrocarbons: the hydrocarbons of greatest accessibility are derived from petroleum and wood
  • Most of the dangerous hydrocarbons are derived from petroleum distillates and include aliphatic (straight-chain) hydrocarbons and aromatic (benzene-containing) hydrocarbons
• Common Hydrocarbons Associated with Human Exposures
  • Citronella Oil
  • Gasoline
  • Jet Fuel
  • Kerdan: aromatic hydrocarbon-enriched petroleum distillate
  • Kerosene (Paraffin)
  • Lamp Oil
  • Lighter Fluid
  • Mineral Seal Oil: mineral seal oil is found in furniture polish
  • Mineral Spirits
  • Turpentine (Pine Oil)
• Types of Hydrocarbon Exposure
  • Unintentional or Intentional Ingestion
  • Unintentional or Intentional Inhalation
  • Dermal Exposure

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Clinical Presentations

Hydrocarbon Ingestion with Aspiration Pneumonitis

• Physiology: accidental or intentional ingestion of hydrocarbons with subsequent aspiration
  • Risk of aspiration is increased with lower viscosity and higher volatility of the hydrocarbon: mineral seal oil has low viscosity and is a particular risk
  • Volatile hydrocarbons may displace alveolar oxygen, leading to hypoxia
  • Although effects of hydrocarbon on pulmonary surfactant have been suggested to be contributory, the chemical pneumonitis due to hydrocarbons appears to be non-specific
  • Hydrocarbon contact with alveolar membranes -> hemorrhage, hyperemia, edema, surfactant inactivation, leukocyte infiltration, and vascular thrombosis -> pneumonitis and acute lung injury
• Diagnosis
  • CXR/Chest CT: infiltrates predominantly in aspiration-prone lung regions
• Clinical
  • Pulmonary Manifestations (due to aspiration)
    • Hydrocarbon Pneumonitis (see Pneumonia): symptoms usually begin with the first few hrs after exposure and usually resolve within 2-8 days
    • Acute Lung Injury-ARDS (see Acute Lung Injury-ARDS)
    • Pneumatocele (see Cystic-Cavitary Lung Lesions): common complication
  • Neuro Manifestations
    • Initial Phase: disinhibition (similar to alcohol intoxication) or narcotic-like depression -> euphoria
    • Later Phase: lethargy, headache, obtundation, coma
    • Seizures: uncommon (likely are related to hypoxia)
  • GI Manifestations
    • Local irritation with abdominal pain and nausea
    • Vomiting: increases likelihood of aspiration
  • Cardiac Manifestations
    • Arrhythmias: due to hypoxia, myocardial sensitization to catecholamines, and direct myocardial damage
    • Sudden death: has been reported to occur as a result of coronary vasospasm due to hydrocarbons
  • Hematologic Manifestations
    • Bone marrow toxicity
    • Hemolytic Anemia (see Hemolytic Anemia)
  • Other Manifestations
    • Acute Kidney Injury (see Acute Kidney Injury): with chlorinated hydrocarbons
    • Fulminant Hepatic Failure (see Fulminant Hepatic Failure): with chlorinated hydrocarbons
    • Renal Tubular Acidosis (see Metabolic Acidosis-Normal Anion Gap): with toluene toxicity
    • Skin Irritation or Chemical Burns: with skin contact
• Treatment: supportive care
• Prognosis: highest rates of morbidity and mortality result from accidental ingestion by children under 5 y/o

Fire Eater’s Lung

• Epidemiology: variant of hydrocarbon pneumonitis, which occurs predominantly in young adults who are exposed to hydrocarbons via their use in “fire-eating” displays
• Physiology: as above
• Clinical
  • Pulmonary Manifestations (due to aspiration)
    • Hydrocarbon Pneumonitis (see Pneumonia): symptoms usually begin with the first few hrs after exposure and usually resolve within 2-8 days
    • Acute Lung Injury-ARDS (see Acute Lung Injury-ARDS)
    • Pneumatocele (see Cystic-Cavitary Lung Lesions): common complication
• Treatment: supportive care

Hydrocarbon Fume Inhalation

• Epidemiology
• Physiology: inhalation of hydrocarbon fumes (in contrast to aspiration of ingested hydrocarbons, as in seen in hydrocarbon aspiration pneumonitis)
• Clinical: main clinical features of hydrocarbon fume inhalation are usually neurologic and cardiac
  • Pulmonary Manifestations
    • Acute Lung Injury-ARDS (see Acute Lung Injury-ARDS): unusual, but has been reported
  • Neuro Manifestations: common
  • Cardiac Manifestations: common
• Treatment: supportive care

Other Manifestations

• Contact Dermatitis-Irritant Type (see Contact Dermatitis)

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References

• Mineral spirits inhalation associated with hemolyis, pulmonary edema, and ventricular fibrillation. Ann Int Med 1991; 151: 1437-1440