Therefore, at steady state:
Therefore, (10) reduces to:
| Net CO2 production: | |
| (1) |
| Net O2 consumption: | |
| (2) |
| Respiratory quotient: | |
| (3) |
| Inspired & expired gas composition: | |
| (4) |
| (5) |
| X represents gases that are neither produced nor excreted. Therefore, at steady state: | |
| (6) |
| Solving for | |
| (7) |
| Using (7) to restate (1) and (2) as | |
| (8) |
| (9) |
| Substituting (8) and (9) into (3): | |
| (10) |
| The same result can be obtained by solving for | |
| (7a) |
| (8a) |
| (9a) |
| (10a) |
| Under normal physiologic circumstances, Therefore, (10) reduces to: | |
| (11) |
| By Dalton's law of partial pressures, the full humidification of alveolar air and the high diffusibility of CO2: | |
| (12) |