Mechanismus einer Toleranzsteigerung bei wiederholter Einatmung von Lungen�dem erzeugenden Gasen

Pathogenesis of phosgene poisoning

Phosgene inhalation in concentrations greater than 1 ppm may produce a transient bioprotective vagus reflex with rapid shallow breathing in some individuals. Phosgene concentrations greater than 3 ppm are moderately irritating to eyes and upper airways. Toxic phosgene doses (greater than or equal to 30 ppm X 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.

Early diagnosis of phosgene overexposure

At the present time, the following parameters can be recommended for "early diagnosis" of phosgene overexposure: Phosgene indicator paper badges, to be worn by all persons involved in handling phosgene (these badges permit immediate estimation of the exposure dose in each individual case); Observation of the initial irritative symptoms of the eye and the upper respiratory tract after phosgene inhalation can provide a rough indication of the inhalation concentration and dose; X-ray photographs of the lungs make it possible to detect incipient toxic pulmonary edema at an early stage, during the clinical latent period. A number of additional parameters require further critical investigation.