Ether Clearance as a Measure of Alveolar Ventilation I. A Demonstration of Factors that Influence the Effectiveness of Intermittent Positive Pressure Breathing (IPPB/I) Therapy

¹ Buffalo, New York

A new method of determining effective ventilation in a variety of laboratory and clinical problems is presented. The measurement of ether clearance from the lungs following its administration by intravenous solution is a relatively simple and safe procedure which avoids the difficulties of previous methods for alveolar gas determinations. As such, it is applicable in both normal and abnormal lungs, in anesthetic and non-anesthetic states and in rebreathing studies when alterations in the usual respiratory gases are not desirable.

The feasibility of this new method is illustrated by laboratory demonstrations of the effects of some variables in intermittent positive pressure breathing (IPPB/I) on ventilation in dogs. Ventilation increased in proportion to peak inspiratory pressure, to the rate of respiration, and in general proportion to the size of the animal when the airway was unobstructed. Ventilation was not, however, directly proportional to peak inspiratory flow rate, nor to frequency of respiration in the partially obstructed airway. The further applicability and studies of these principles by this method in clinical subjects is indicated.