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Rate of change of alveolar carbon dioxide and the control of ventilation during exercise.

1984; Wiley; Volume: 355; Issue: 1 Linguagem: Inglês

10.1113/jphysiol.1984.sp015401

1469-7793

Christopher Allen, N L Jones,

Cardiovascular and exercise physiology

The relationship between rate of change of alveolar PCO2 (delta PA, CO2/delta te), CO2 output (VCO2) and ventilation (VE) has been determined following a rapid increase in exercise intensity, to test the hypothesis that VE is related to VCO2 by a feed‐forward control system responding to delta PA, CO2/delta te. There was a close relationship between delta PA, CO2/delta te and VCO2 (delta PA, CO2/delta te = 3.2 VCO2 + 0.85), but delta PA, CO2/delta te increased more rapidly than VCO2. Increases in mean inspiratory flow, an index of inspiratory drive, were more closely related to changes in delta PA, CO2/delta te than to changes in VCO2. Increases in VE during transient and steady‐state conditions may be described by the equation: VE = 6.76 delta PA, CO2/delta te ‐3.50, a relationship which is consistent with a feed‐forward control system.