Table 3.
Comparison of the parameters at peak exercise between treatments with tiotropium and oxitropium in incremental exercise testing
| Tiotropium | Oxitropium | P-value | |
|---|---|---|---|
| Exercise time (s) | 541 ± 227 | 498 ± 217 | 0.014 |
| Oxygen uptake (mL/minute) | 855 ± 287 | 821 ± 275 | |
| Carbon dioxide production (mL/minute) | 923 ± 362 | 889 ± 356 | 0.042 |
| Oxygen uptake/weight (mL/kg/minute) | 15.0 ± 4.8 | 14.5 ± 4.7 | |
| Oxygen uptake (% predicted) | 63.8 ± 25.7 | 61.5 ± 24.5 | |
| Minute ventilation (L/minute) | 34.4 ± 10.9 | 32.6 ± 10.5 | 0.012 |
| Heart rate (beats/minute) | 125 ± 17.8 | 122 ± 16.4 | |
| PaO2 (mmHg) | 67.1 ± 12.4 | 69.6 ± 17.8 | |
| PaCO2 (mmHg) | 43.0 ± 5.0 | 43.7 ± 5.9 | |
| Dyspnea index (%)a | 95.7 ± 19.2 | 102.0 ± 25.9 | |
| HR/predicted maximum HR (%)b | 83.1 ± 12.4 | 81.6 ± 11.6 | |
| Lactate (mEq/L) | 4.2 ± 1.7 | 3.7 ± 1.8 | |
| Norepinephrine (ng/mL) | 1.95 ± 0.63 | 2.08 ± 0.81 |
Notes:
a
Dyspnea index (%) = (minute ventilation (L/minute) at peak exercise)/(maximal voluntary ventilation (L/minute) × 100;
b
predicted maximum HR (adult) = 220 − age (years). Data are presented as mean ± standard deviation.
Abbreviations: HR, heart rate; PaCO2, arterial carbon dioxide pressure; PaO2, arterial oxygen pressure.