Analysis of ventilation and performance abnormalities by washout in alveolar air and arterial blood continuous measurement of inert gas

Abstract

The availability of a rapidly responding arterial catheter and gas analyzer permits the observation of inert gas washout from arterial and alveolar sources. These curves are a logical development of alveolar washout techniques and appear to provide significant new information. While a detailed and formal mathematical treatment of combined alveolar, arterial, and mixed venous washout curves has not yet been derived, inspection and measurement of the y-intercept of the terminal slow space has provided considerable understanding into the distribution of V/Q ratios in the critically ill patient.