[Morphology of pulmonary atelectasis in patients operated on and not operated on taking into account pulmonary surfactant state].

The results of clinico-anatomical analysis and of histological examinations of 210 cases of atelectasis with simultaneous study of lung surfactant (126 cases) are described. Electron microscopic examinations of lung tissues were conducted in 8 cases of early autopsy. The postoperative atelectases were compared with those in nonoperated patients. The postoperative atelectases were characterized by substantially larger lesions and prevalence of reflectory, aspiratory, and polyetiological types of lesions. A certain dynamics of changes in the lung surfactant activity was established: a substantial increase of the activity during in the acutest phase of atelectasis and its significant decline towards the end of the first week of the disease. The changes of the surfactant indices directly depend on the synthesizing activity of type II pneumocytes. The decrease of the surfactant occurs secondarily as atelectasis advances.