Ventilatory response to carbon dioxide in bronchial asthma and chronic obstructive lung disease.
A comparative study was made of ventilatory and airway occlusion pressure (P0.1; a parameter reflecting respiratory center output) responses to carbon dioxide between 11 patients with bronchial asthma and 10 chronic obstructive lung disease (COLD). Increments in ventilatory volume (VE) produced by a rise in end-tidal CO2 pressure (PETCO2), i.e. delta VE/BSA/delta PETCO2, were smaller in 4 patients with hypercapnic COLD than in 6 normal subjects. On the other hand, increments in P0.1 produced by an elevation of PETCO2 (i.e. delta P0.1/delta PETCO2) tended to be diminished in patients with hypercapnic COLD. Higher values for both VE/BSA and P0.1 were observed in 6 patients with normocapnic COLD, but the differences from corresponding control values failed to achieve statistical significance due to a large variance. In 11 patients with bronchial asthma without attack, VE/BSA elevated significantly at PETCO2 levels of 50 and 60 torr, but values of delta VE/BSA/delta PETCO2 were virtually same as those in normal subjects.
D001249:Asthma / Q000503:physiopathology*; D002245:Carbon Dioxide; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology; D008173:Lung Diseases, Obstructive / Q000503:physiopathology*; D010313:Partial Pressure; D011659:Pulmonary Gas Exchange; D012119:Respiration; D013147:Spirometry; D013990:Tidal Volume
D002245:Carbon Dioxide