Table 2.
Mean ( ± SD) physiological variables across conditioned respiratory tasks.
| Anticipation | Resistance | ||||
|---|---|---|---|---|---|
| No impending resistance | Uncertain impending resistance | Certain impending resistance | Average | Peak | |
| Pressure (cmH2O) |
-0.14 (0.11) | -0.17 (0.12) | -0.18 (0.24) | -5.80 (3.64)* | -14.67 (8.28)* |
| PETCO2
(%) |
4.41 (0.71) | 4.41 (0.67) | 4.32 (0.68)* | 4.46 (0.67) | 4.62 (0.66)* |
| PETO2
(%) |
18.1 (1.0) | 18.1 (1.0) | 18.3 (1.1)* | 18.5 (1.0)* | 18.9 (1.0)* |
| Respiratory rate (min-1) | 12.8 (3.7) | 12.5 (3.8) | 12.4 (3.6) | 11.2 (4.6) | 13.8 (5.9) |
| RVT increase (%) | -4.4 (7.4) | 7.8 (19.6)* | 11.0 (23.0)* | -16.1 (21.6)* | 16.6 (28.5)* |
*Significantly (p<0.05) different from ‘no impending resistance’ condition.
Abbreviations: Pressure, average mouth pressure across all ventilatory cycles; PETCO2, pressure of end-tidal carbon dioxide; PETO2, pressure of end-tidal oxygen; RVT, respiratory volume per unit time.