Table 3

Ventilation, breathing reserve, typical end criteria for maximum effort and reason for termination during the cardiopulmonary exercise test at baseline and after intervention

VariablesExerciseControlp Value
Mean baseline, after surgery
 Peak ventilation, L/min48.5±13.246.1±14.80.517
 Breathing reserve*, %39.2±13.644.4±12.30.122
 Respiratory exchange ratio1.05±0.081.08±0.090.132
 Blood lactate concentration†, mmol/L3.9±1.14.6±1.90.159
 Maximum heart rate, beats/min140±18.2132±23.50.154
 6–20 Borg scale, rating number17.5±0.817.3±1.20.937
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/min60.3±16.949.8±15.80.025
 Breathing reserve*, %29.1±17.339.7±13.30.017
 Respiratory exchange ratio1.09±0.081.12±0.090.220
 Blood lactate concentration†, mmol/L4.9±1.75.1±2.20.730
 Maximum heart rate, beats/min148±19.9136±21.80.045
 6–20 Borg scale, rating number17.7±1.417.6±0.90.652
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

  • .