THE CHANGING STATE OF BREATHING DURING INHALATION OF CO₂, STUDIED WITH AN INEXPENSIVE, RECORDING CO₂-ANALYZER

¹ Department of Therapeutics, University of Edinburgh

A method is described for recording alveolar CO₂ tension using simple and inexpensive apparatus. The changing state of hyperventilation due to CO₂ has been studied and a procedure devised for deriving the steady-state CO₂-response line from data obtained during the changing state. This procedure has considerable practical advantages over conventional methods. Evidence is presented to show that the time needed for equilibration of CO₂ between the arterial blood and the cells of the respiratory centre is of the order of 4 min.

Note:

We are greatly indebted to Professor Sir Derrick Dunlop for providing facilities for this work. Dr. D. J. C. Cunningham's criticism has been a constant stimulus. Messrs. Geigy Pharmaceuticals Ltd. provided a generous grant for apparatus, and one of us (J. L. A.) held a Riker Research Fellowship during this work. We thank Miss Susan Cole for help with some of the experiments.