Ventilation, breathing reserve, typical end criteria for maximum effort and reason for termination during the cardiopulmonary exercise test at baseline and after intervention
| Variables | Exercise | Control | p Value |
|---|---|---|---|
| Mean baseline, after surgery | |||
| Peak ventilation, L/min | 48.5±13.2 | 46.1±14.8 | 0.517 |
| Breathing reserve*, % | 39.2±13.6 | 44.4±12.3 | 0.122 |
| Respiratory exchange ratio | 1.05±0.08 | 1.08±0.09 | 0.132 |
| Blood lactate concentration†, mmol/L | 3.9±1.1 | 4.6±1.9 | 0.159 |
| Maximum heart rate, beats/min | 140±18.2 | 132±23.5 | 0.154 |
| 6–20 Borg scale, rating number | 17.5±0.8 | 17.3±1.2 | 0.937 |
| Reason for test termination | |||
| Leg fatigue, n (%) | 5 (17) | 5 (16) | |
| Dyspnoea, n (%) | 15 (50) | 15 (48) | |
| General fatigue, n (%) | 5 (17) | 8 (26) | |
| After intervention | |||
| Peak ventilation, L/min | 60.3±16.9 | 49.8±15.8 | 0.025 |
| Breathing reserve*, % | 29.1±17.3 | 39.7±13.3 | 0.017 |
| Respiratory exchange ratio | 1.09±0.08 | 1.12±0.09 | 0.220 |
| Blood lactate concentration†, mmol/L | 4.9±1.7 | 5.1±2.2 | 0.730 |
| Maximum heart rate, beats/min | 148±19.9 | 136±21.8 | 0.045 |
| 6–20 Borg scale, rating number | 17.7±1.4 | 17.6±0.9 | 0.652 |
| Reason for test termination | |||
| Leg fatigue, n (%) | 4 (56) | 7 (26) | |
| Dyspnoea, n (%) | 14 (56) | 11 (41) | |
| General fatigue, n (%) | 5 (20) | 7 (26) | |
Data are presented as mean±SD or n (%).
*Breathing reserve (%) was calculated using the following equation: ([MVV–VEmax]/MVV)×100.
†Blood lactate concentration was taken 60 sec after termination as an indicator of high effort.25
MVV, maximum voluntary ventilation; VEmax, maximum minute ventilation
.