Effect of mechanical loading on ventilatory response to CO2 and CO2 excretion

The ventilatory response to CO(2) (S) and respiratory exchange ratio have been measured in 10 healthy subjects breathing naturally and through added resistive loads. The changes in these values produced by the added loads were shown to be correlated with the unloaded CO(2) responsiveness. The results indicated that poorly responsive individuals had a greater depression of ventilatory response to CO(2) and were more liable to retain CO(2).These observations raise the possibility that the constitutional CO(2) responsiveness of an individual influences the alveolar ventilation achieved in the presence of airways obstruction. The propensity to develop respiratory failure may thus be conditioned by the premorbid CO(2) responsiveness.