Physiological inferences from intra-breath measurement of pulmonary gas exchange

Intra-breath measurements allow study of certain pulmonary variables. The authors show that mean alveolar PCO/sub 2/ (which closely reflects arterial PCO/sub 2/ in normal subjects) and volume series dead space can be measured online, breath-by-breath. Further study of the intra-breath profiles of such variables (e.g. PCO/sub 2/, PO/sub 2/, R, N/sub 2/, Ar/N/sub 2/) are expected to improve understanding of both normal and impaired lung function.<>