Ventilatory Response to Carbon Dioxide in Pulmonary Emphysema

Abstract

The ventilatory response to CO2 is diminished in the patient with pulmonary emphysema to an amt. which is proportional to the degree of CO2 retention. This general relationship defines a trend which the subject without pulmonary disease also obeys if he has a disturbance in acid base balance resulting in changed CO2 retention. As the degree of CO2 retention is corrected in the subject without pulmonary disease, his ventilation response changes in a predictable fashion according to this trend. The CO2 content in the subject with respiratory acidosis secondary to chronic pulmonary emphysema can be lowered by the carbonic anhydrase inhibitor "6063," but his ventilation response to inspired CO2 is less than predicted. This appears to be due to the mechanical limitations of that disease. Certain predictions concerning changes in the sensitivity of the respiratory center secondary to CO2 adaptation in health or disease are made and discussed.