Table 3.
Relationship of ventilation, oxygenation and dyspnea to exercise tolerance. Peak VT: tidal volume achieved at the end of the test, peak VE – minute ventilation achieved at the end of the test, peak IVC – inspiratory vital capacity achieved at the end of the test, IVC fall – percentage change of inspiratory vital capacity between start and end of the test, peak SpO2 – peak oxygen saturation measured by pulse oximetry achieved at the end of the test, SpO2 fall – percentage fall of oxygen saturation between start and end of the test, peak VAS – dyspnea measured by visual analog score at the end of the test, 6MWD – distance reached during the 6-min walk-test, pVO2 (6MWT) - peak oxygen consumption achieved during the 6-min walk-test, pVO2 (CPET) - peak oxygen consumption achieved during cardiopulmonary exercise test.
| 6MWD | pVO2 (6MWT) | pVO2 (CPET) | |
|---|---|---|---|
| peak VT | r = 0.5613 P = 0.0154 |
r = 0.7384 P = 0.0005 |
r = 0.2121 P = 0.3982 |
| peak VE | r = 0.6702 P = 0.0023 |
r = 0.89 P < 0.0001 |
r = 0.516 P = 0.0284 |
| peak IVC | r = 0.5301 P = 0.0236 |
r = 0.6299 P = 0.0051 |
r = 0.1599 P = 0.5264 |
| IVC fall | r = −0.3261 P = 0.1867 |
r = −0.369 P = 0.1318 |
r = −0.4977 P = 0.0356 |
| peak SpO2 | r = 0.5311 P = 0.0233 |
r = 0.3628 P = 0.139 |
r = −0.05423 P = 0.8308 |
| SpO2 fall | r = 0.05596 P = 0.8255 |
r = 0.05471 P = 0.8293 |
r = −0.2899 P = 0.2433 |
| peak VAS | r = −0.2727 P = 0.2735 |
r = −0.02295 P = 0.928 |
r = −0.09006 P = 0.7223 |