Hydrogen Sulfide Poisoning

Aka: Hydrogen Sulfide Poisoning, Hydrogen Sulfide Toxicity, Hydrogen Sulfide, Hydrogen Sulfide Gas

1. Background: Hydrogen Sulfide
   1. Hydrogen Sulfide is a Sulfur-Based Toxic Gas
      1. Flammable, colorless gas
      2. Poisonous
      3. Malodorous (rotten egg smell)
      4. Air Pollutant
   2. Manufacturing reagent
      1. Chemical manufacturing
      2. Petroleum processing
      3. Sewage processing
      4. Metallurgy
      5. Agriculture
      6. Analytical Chemistry
2. Pathophysiology: Hydrogen Sulfide Toxicity
   1. Toxicity
      1. Cytochrome C Oxidase inhibition
      2. Neuronal Potassium channels hyperpolarized
      3. Oxygen radicals form
      4. Corrosive at mucous membranes
   2. Concentrations >100 ppm result in Loss of Smell by olfactory paralysis (no rotten egg smell detected)
   3. Concentrations >500 ppm are rapidly lethal by inhalation
3. History
   1. Sudden collapse in an enclosed work area (esp. if rotten egg smell was reported)
4. Signs
   1. Ocular
      1. Conjunctivitis
   2. Cardiopulmonary
      1. Dyspnea
      2. Cyanosis
      3. Rales
      4. Acute Respiratory Distress Syndrome (ARDS)
   3. Gastrointestinal
      1. Nausea
      2. Vomiting
   4. Neurologic
      1. Headache
      2. Syncope
      3. Seizures
5. Labs
   1. See Poisoning
   2. Sulfide concentrations
      1. Blood sulfide concentration
      2. Blood and urine thiosulfate concentration
   3. Venous Blood Gas (or Arterial Blood Gas)
      1. Metabolic Acidosis (due to Lactic Acidosis)
6. Imaging
   1. Head MRI or Head CT
      1. As indicated for neurologic findings
7. Management
   1. Respiratory Management
      1. Nonrebreather 100% oxygen
      2. Noninvasive Positive Pressure Ventilation (e.g. BiPap) or Mechanical Ventilation with PEEP
   2. Hypotension management
      1. Intravenous Fluids
      2. Vasopressors
   3. Sulfide Antidotes
      1. Sodium Nitrite 3% 0.2 ml per kg (children) up to 10 ml or 300 mg in adults IV over 2-4 min
      2. Hydroxycobalamin (cyanokit) 2.8 ml/kg or 70 mg/kg (children) up to 200 ml or 5 g in adults over 15 min
      3. Cobinamide (experimental)
   4. Disposition
      1. Admit all patients with respiratory of neurologic signs or symptoms
      2. Patients with only mild mucosal irritation (e.g. Conjunctivitis) may be discharged home
8. Complications
   1. Neurologic and psychiatric sequelae may be longstanding
9. Resources
   1. Hydrogen Sulfide (OSHA)
      1. https://www.osha.gov/hydrogen-sulfide
   2. Hydrogen Sulfide Toxicity (Stat Pearls)
      1. https://www.ncbi.nlm.nih.gov/books/NBK559264/
10. References
    1. Tomaszewski (2017) Crit Dec Emerg Med 31(10): 24