Pathogenesis of Phosgene Poisoning

Abstract

Phosgene inhalation in concentrations > 1 ppm may produce a transient bioprotective vagus reflex with rapid shallow breathing in some individuals. Phosgene concentrations > 3 ppm are moderately irritating to eyes and upper airways. Toxic phosgene doses ( ≥ 30 ppm-min) inhaled into the terminal respiratory passages render the blood-air-barrier more permeable to blood plasma, which gradually collects in the lung. Some time passes, however, until the collection of fluid provokes signs and symptoms. This period in which the patient experiences relative well-being is known as the clinical latent phase. The clinical symptoms which follow and the pathological changes underlying them are discussed in detail; dose-effect relationships are demonstrated. The regression phase after poisoning has been overcome is briefly sketched.