Diphosgene symptoms

Inhalation is the major route of exposure. Diphosgene is extremely damaging to mucous membranes, eyes, skin, and the respiratory tract, and may cause minor irritation to severe tissue damage and death. Toxicity effects vary with the concentration of vapor and the length of exposure. Signs and symptoms of toxicity may be immediate or delayed. The delayed (up to 6h) acute respiratory distress syndrome is characteristic of chocking agent inhalation. 

Diphosgene usually causes irritation to eyes and the upper respiratory tract at low concentration. Inhalation can cause fatality if the concentration is > 25 ppm. Surface burns are the common symptoms... 

For the respiratory tract, inhalation can cause spasms, inflammation and edema of the larynx and bronchi, dyspnea, cyanosis, pneumonia, and pulmonary edema. Serious symptoms, such as pulmonary edema and asphyxiation, may not be observed for hours after overexposure. Occasionally, cardiac failure occurs as a complication of severe pulmonary edema. With regards to the cardiovascular system, diphosgene can cause rapid heartbeat and hypotension. Gastrointestinal exposure may cause nausea and vomiting in patients and may be fatal. 

After completing decontamination, the only effective management consists of close observation for the development of respiratory distress and supportive care. There are no known antidotes for pulmonary agent exposure. Patients exposed to phosgene or diphosgene require monitoring for a minimum of 12h because of the possibility of delayed symptoms (2). Strict bed rest is essential for patients with mild and moderate exposmes, because any exertion, even minimal exertion, can shorten the clinical latent period and inaease the severity of respiratory symptoms (8). In symptomatic patients, physical activity can cause clinical deterioration and even death (8). Supportive care consists of managing secretions, bronchospasm, hypoxia, and pulmonary edema. 

The major symptoms of diphosgene poisoning are similar to those of phosgene, as listed in Table 5.18 (p. 287). 

Onset of symptoms is very rapid with even a moderate concentration of exposure causing severe respiratory dysfunction within 6-8 hours. It is more toxic than chlorine, but less so than phosgene or diphosgene. 

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