[Postoperative ventilation in non-intubated patients with iron lung versus conventional ventilation]

Postoperative ventilation using a steel lung is an alternative to conventional ventilation through an endotracheal cannula. Both methods were compared in two groups of patients undergoing major abdominal surgery. Group A was ventilated using a Servo Ventilator 900C, whereas group B was ventilated using a newly designed steel lung. The duration of ventilation using the steel lung and that of postoperative intubation were significantly shorter than those used in group A, in spite of a higher anesthesiological and surgical risk in patients in group B. pO2 was significantly increased during ventilation with the steel lung in comparison to conventional ventilation. An automatic classification of EEG activity was used to estimate depth of anesthesia. This showed a close correlation between clinical signs and anesthesiological levels. The spectroanalytical evaluation of ventilation curves allowed the early recognition of spontaneous breathing and determined tidal volumes using steel lung ventilation.