Table 5.
End-Tidal Carbon Dioxide Kinetics
| Young | Middle-Aged | Older | P-Value | |
|---|---|---|---|---|
| PETCO2 Baseline (mmHg) | 34.6 ± 4.0 | 34.4 ± 2.8 | 31.6 ± 4.0 | <0.001*# |
| PETCO2 Time Delay (s) | 33.5 ± 53.0 | 42.5 ± 63.4 | 36.6 ± 47.3 | 0.77 |
| PETCO2 τ (s) | 41.3 ± 27.1 | 35.7 ± 21.1 | 46.6 ± 56.1 | 0.51 |
| PETCO2 Amplitude (mmHg) | 7.0 ± 5.0 | 6.7 ± 5.2 | 6.0 ± 4.4 | 0.46 |
| PETCO2 Steady State (mmHg) | 41.8 ± 5.2 | 41.0 ± 5.2 | 37.5 ± 4.7 | <0.001*# |
Data are presented as mean ± standard deviation. PETCO2, end-tidal carbon dioxide; mmHg, millimeters of mercury; s, seconds. The p-value represents the analysis of variance. Symbols indicate significant pairwise differences from Tukey post-hoc analysis:
*
p ≤ 0.025 for young vs. older adults
^
p ≤ 0.025 for young vs. middle-aged adults
#
p ≤ 0.025 for middle-aged vs. older adults.