Sulfur Dioxide Poisoning

Aka: Sulfur Dioxide Poisoning, Sulfur Dioxide, Sulfurous Anhydride, Sulfurous Oxide

1. Background
   1. Highly toxic, colorless, water-soluble, nonflammable gas
      1. Pungent odor and highly irritating
      2. Sulfur Dioxide forms sulfurous acid when combined with water
   2. Sources
      1. Environmental air pollutant
         1. Coal-fired power plants
         2. Copper Smelters
         3. Oil Refineries
         4. Volcanic Eruptions
      2. Chemical agent in Manufacturing (pharmaceutical aid, antioxidant)
         1. Sulfuric Acid Manufacturing
         2. Food Preservation Facilities (e.g. dried fruit preparation)
         3. Fertilizer manufacture
         4. Paper Manufacturing
         5. Disinfectant in breweries, granaries and food factories
2. Mechanism
   1. Upper airway irritation
      1. Water soluble gas deposits as sulfurous acid on mucosa of upper airway and resulting in irritation
   2. Inhalation Injury
      1. Oxidative injury to lung on deep inspiration
3. Pharmacokinetics
   1. Irritation level exposure: 20 ppm
   2. Life threatening level exposure: 100 ppm
4. Findings: Initial Irritant-Level Exposure
   1. Mucosal Irritation
      1. Irritant Conjunctivitis
      2. Nasal irritation
      3. Pharyngitis
   2. Respiratory Irritation
      1. Cough
      2. Wheezing
      3. Chest Tightness
   3. Skin Irritation
      1. Skin redness and pain
      2. Blisters may occur
5. Findings: Significant Inhalation Injury
   1. Bronchospasm or reactive airway findings
   2. Obstructive Lung Disease exacerbation (Asthma Exacerbation, COPD exacerbation)
   3. Acute Respiratory Distress Syndrome
6. Imaging
   1. Chest XRay
      1. Indicated for presentation with ongoing respiratory symptoms
7. Diagnostics
   1. Obtain Pulse Oximetry
8. Management
   1. Decontamination of symptomatic patients
      1. Eye Irrigation
      2. Wash skin
      3. No risk of exposures to medical staff (outside original Sulfur Dioxide exposure site)
   2. Supportive Care
      1. Supplemental Oxygen for Hypoxia
      2. Inhaled or Nebulized Albuterol for bronchospasm, Wheezing
      3. No evidence for Corticosteroids (consider for Obstructive Lung Disease exacerbation)
      4. No antibiotic prophylaxis recommended
   3. Disposition
      1. May discharge at 4-6 hours after exposure if asymptomatic
      2. Hospital observation for persistent respiratory symptoms beyond 4-6 hours from exposure
9. Complications
   1. Chronic Bronchitis
   2. Pulmonary Fibrosis
   3. Bronchiolitis Obliterans
10. Resources
    1. Sulfur Dioxide Exposure Medical Management (CDC)
       1. https://wwwn.cdc.gov/TSP/MMG/MMGDetails.aspx?mmgid=249&toxid=46
    2. Sulfur Dioxide Safety Data Sheet (Canadian Occupational Safety)
       1. https://www.ccohs.ca/oshanswers/chemicals/chem_profiles/sulfurdi.html
    3. Sulfur Dioxide Poisoning (Kansas Poison Control)
       1. https://www.kansashealthsystem.com/-/media/Files/PDF/More-Poisons/Sulfur-Dioxide.pdf
11. References
    1. Tomaszewski (2018) Crit Dec Emerg Med 32(6):32