Gas exchange parameters
| Baseline sea level | Hypoxia at rest | Hypoxia during exercise* | p Value | |
|---|---|---|---|---|
| SpO2,% | ||||
| PAH | 97 (1) | 90 (4)† | 91 (2)† | 0.01 |
| Control | 98 (1) | 94 (2) | 94 (2) | 0.01 |
| PaO2, mm Hg | ||||
| PAH | 86 (10) | 55 (6)* | – | 0.01 |
| PaCO2, mm Hg | ||||
| PAH | 33 (4) | 33 (5)* | – | 0.87 |
| VE, L/min | ||||
| PAH | 13.5 (3.8)† | 13.6 (4.8)† | 21.9 (6.6) | 0.01 |
| Control | 9.5 (2.9) | 8.4 (2.2) | 18.4 (3.5) | 0.01 |
| VT, L | ||||
| PAH | 0.73 (0.25) | 0.71 (0.24) | 1.11 (0.45) | 0.01 |
| Control | 0.67 (0.10) | 0.66 (0.13) | 0.97 (0.23) | 0.01 |
| RR, bpm | ||||
| PAH | 19 (4)† | 19 (5)† | 22 (7) | 0.55 |
| Control | 14 (4) | 13 (5) | 20 (3) | 0.02 |
| VO2, mL.min.kg | ||||
| PAH | 4.68 (0.75) | 4.54 (1.33) | 6.92 (1.97) | 0.01 |
| Control | 4.26 (0.74) | 3.57 (0.51) | 8.54 (2.11) | 0.01 |
| Borg 1–10 | ||||
| PAH | 0.4 (0.5)† | 1.0 (1.1)† | 1.7 (0.8)† | 0.01 |
| Control | 0.0 (0.0) | 0.0 (0.0) | 0.1 (0.4) | 0.39 |
Data presented as mean (SD). N=14 PAH, N=7 Control.
*N=11 PAH.
†versus Control unpaired t-test p<0.05.
PAH, pulmonary arterial hypertension; PaO2, pressure of arterial oxygen; RR, respiratory rate; SpO2, pulse oximetry; VE, minute ventilation; VO2, oxygen uptake; VT, tidal volume.