[Airway resistance and lung volumes (author's transl)].

Whole-body plethysmography for measuring airway resistance and intrathoracic gas volume is a valuable tool for diagnosing pulmonary and airway functions. It is desirable to know momentary airway resistance in the course of a forced expiration and vital capacity in relation to predicted and actual thoracic gas volume as well as predicted and actual total capacity. This is a reliable means of discovering limitations of lung ventilation despite normal airway resistance during normal ventilation. With a computer and plotter attached to a whole-body plethysmograph such volume-airway resistance curves can be rapidly and well reproduced without stressing the test person. In addition, it also makes it possible to measure routinely the volume resistance breaking point (largely comparable to "closing capacity") even in ill patients.