View source for Phosgene

''Not to be confused with [[phosgene oxime]] (CX)''

==Background==
[[File:Phosgene poster ww2.jpg|thumb|Phosgene poster]]
*Phosgene (carbonyl chloride), chemical formula COCl2, is a colorless gas (at low temperatures, can also exist as a liquid)
*Classically described as having odor of freshly cut hay
*Used as a chemical weapon, and accounted for 80% of deaths from poison gas in WWI<ref name="Hardison">Hardison LS, Wright E, Pizon AF. Phosgene Exposure: A Case of Accidental Industrial Exposure. Journal of Medical Toxicology. 2014;10(1):51-56. doi:10.1007/s13181-013-0319-6.</ref>
*Currently most frequently used in the industrial setting
**Used in the manufacture of plastics, dyes, pharmaceuticals and pesticides<ref name="Gutch">Gutch M, Jain N, Agrawal A, Consul S. Acute accidental phosgene poisoning. BMJ Case Reports. 2012;2012:bcr1120115233. doi:10.1136/bcr.11.2011.5233</ref>
*Heavier than air → stays close to ground

===Pathophysiology===
*Hydrolysis = phosgene reacts with water in the lungs to form hydrochloric acid
**Likely not clinically significant<ref name="Hardison" />
*Acylation = causes oxidative damage and depletes glutathione<ref name="Hardison" />
**Damages alveolar membrane, increases vascular permeability
**Leads to noncardiogenic pulmonary edema

==Clinical Features==
*Due to lower water solubility than other irritant gases (e.g. Chlorine gas), phosgene causes less immediate irritation of the mucous membranes and therefore is able to penetrate to and damage the lower respiratory tract
*Immediate effects (depends on concentration) - mucous membrane irritation, tachypnea, shallow breathing
**At low concentrations, no immediate symptoms may be noted<ref name="Hardison" />
*Latent phase length is inversely proportional to inhaled dose<ref name="Gutch" />
*Delayed effects (depends on total inhaled dose) - respiratory distress, cough, and finally pulmonary edema
**May take hours to develop

==Differential Diagnosis==
{{Chemical weapon DDX}}

==Evaluation==
*No specific test for exposure - workup should be based on history and sypmtoms. Consider:
**Laboratory studies (e.g. CBC, CMP, lactate)
**Chest X-ray
**ABG

==Management==
*Supportive care is the mainstay of treatment (no specific antidote exists)
*Use supplemental oxygen only as needed, and then at low concentrations to avoid reactive oxygen species formation<ref name="Hardison" />
*If intubation required, use ARDS lung-protective strategies

===Specific treatment options<ref name="Hardison" />===
''Note: Evidence is lacking, and generally based on case reports and expert opinion - consultation with local [[poison control]] is recommended''
*Corticosteroids
*N-acetylcysteine (IV or nebulized)
*NSAIDS (e.g. Ibuprofen, Colchicine)
*Terbutaline
*Nebulized albuterol

==Disposition==
*Admit

==See Also==
*[[Pulmonary chemical agents]]

==References==
<references/>

[[Category:Toxicology]]