Gas Exchange in the Lung, Computer Feed Back Controlled Physiological Matching of Artificial Ventilation

Abstract

Maintenance of adequate gas exchange in the critically ill can often only be achieved by artificial ventilation. Physiological negative pressure insufflation was primarily achieved by Sauerbruch’s negative-pressure chamber and later developed to an artificial respirator generally called the “iron lung”. However, for ventilation respectively insufflation the body of the patient needed to be enclosed in a chamber and access for nursing measures, positioning of the patient, cleaning e.g. was difficult. Furthermore, changes of parameters in ventilation, introduction of positive pressure gradients if needed and high frequent ventilation mode was not possible. Intermittent positive pressure ventilation via endotracheal tubes, as used generally today, proved to be more practical and efficient.