Alveolar pressure response to “top-hat” gas flow or pressure waves in artificial ventilation

Abstract

Patients and dogs were anaesthetized and paralysed and their airways were exposed to an instantaneous pressure change applied during artificial ventilation. Measurements of respiratory gas flow and volume, and of trachéal, oesophageal and pleural pressures were made. The results presented support the hypothesis that alveolar pressure responds to an instantaneous pressure change in a patient's airway during artificial ventilation by an instantaneous step change of pressure. Methods for measuring oesophageal pressure and for calculating kinetic respiratory resistance and compliance are discussed.