Pulmonary effects of acute exposure to nitrous fumes.

Four cases of poisoning by nitrous fumes are reported. Three patients presented with pulmonary oedema, and one of these progressed to the phase of bronchiolitis obliterans; the fourth patient presented with the clinical features of bronchiolitis obliterans. Pulmonary function studies in both phases showed a predominantly restrictive pattern of ventilatory abnormality with a tendency to hypoxaemia, hypocapnia, and reduced transfer factor. Complete recovery followed prompt treatment with corticosteroids. It is emphasized that three of these four accidents were preventable.