Treatment in the latent and chronic phase

Regrettably there is, as yet, no known antidote to phosgene poisoning. Consequently treatment is usually directed to the main symptom - toxic pulmonary oedema - the development of which is dose-related [1374]. 

Moderate doses (50-150 p.p.m. min) can produce sub-clinical pulmonary oedema, which may be prevented or alleviated by administering glucocorticoids (dexamethasone-nicotinate aerosol, 3x5 puffs, and prednisolone, 0.1 g intravenously) as soon as possible after exposure. If radiography reveals no sign of oedema after eight hours, the patient may be discharged. If radiography is not available, supervision should be continued for twenty-four hours. 

With moderate-large doses ( 150 p.p.m. min), toxic pulmonary oedema must be expected doses of 300 p.p.m. min or greater are potentially lethal. X-ray photographs taken two hours after exposure are recommended for early diagnosis. In these cases, large amounts of glucocorticoids should be administered as soon as possible after exposure 

Sodium hydrogencarbonate given intravenously may be used to correct acidosis resuiting from phosgene intoxication. However, this should be given with caution to avoid alkalosis and increase in oedema due to over-infusion [1359]. 

Sedatives may be used if the patient seems severely agitated, although the use of morphine has been discouraged because of its depressive effect on the respiratory centre. 

---