Unterdruck and Überdruck, 1904

Abstract At the beginning of the 20th century, elective surgery within the chest was not possible; to open the pleural cavity under anesthesia meant death to the patient in almost all cases. The few exceptions to this rule—resulting from diffuse pleural adhesions or brief duration of surgical pneumothorax in robustly healthy persons—still did not permit deliberate intrathoracic procedures to be done with any expectation of success. Two papers that appeared consecutively in the same journal in 1904 proposed opposite approaches to respiratory support in the presence of surgical pneumothorax, by means of differential pressure chambers. Both methods were reasonably successful in clinical use. The life span of the static-pressure chambers was brief, however, and within a few years they were being superseded by cyclic positive-pressure inflation via the airway. The opposing methods are remembered under their German names, Unterdruck and Uberdruck.