Phosgene

Background

• phosgene (COCl2) is a highly toxic, colorless gas or liquid
• gained infamy in WWI - responsible for 85% of deaths due to chemical weapons
• pulmonary irritant
• major complication is non-cardiogenic pulmonary edema
• used in chemical reactions - large scale exposures usually 2/2 industrial accidents
  • manufacturers of dyes, resins, coal tar, pesticides
• some people may note a smell of newly mown hay

Clinical Features

• eye and throat symptoms may occur at very low concentrations
• unpredictable latent phase
• development of noncardiogenic pulmonary edema

Pathophysiology

• acrylation reaction with amino, hydroxyl, and sulfhydryl goups
• membrane structural changes, protein denaturation, depletion of glutathione
• increased vascular permeability leads to noncardiogenic pulmonary edema

Evaluation

• high index of suspicion, ask about work history/exposures
• no combination of labs/xrays can predict whether pt will develop pulmonary edema
• latent phase can be 30 min - 72hrs but significant exposures usually developed pulmonary symptoms within 24 hrs

Management

• supportive care
• with pulmonary edema pts may require intubation with high PEEP
• albuterol for bronchospasm
• steroids recommended but no solid evidence for efficacy
• no specific antidote exists

References

1. Balmes JR. Phosgene. Olson KR, ed. Poisoning and Drug Overdose. 6th ed. New York, NY: McGraw-Hill; 2012. Chapter 127.
2. Grainge C, Rice P. Management of phosgene-induced acute lung injury. Clin Toxicol (Phila). 2010 Jul. 48(6):497-508
3. Gresham C, LoVecchio F. Industrial Toxins. Tintinalli JE, Stapczynski JS, Cline DM, Ma OJ, Cydulka RK, Meckler GD, eds. Tintinalli’s Emergency Medicine: A Comprehensive Guide. 7th ed. New York, NY: McGraw-Hill; 2011. Chapter 198