Table 5—

Correlation (r) and determination (r2) coefficients of maximal tidal volume (VT,max) to resting respiratory variables in the 52 chronic obstructive pulmonary disease patients

VariableRR2p-value
IC L0.770.59<0.0001
FEV1 L0.610.37<0.0001
Pa,O2 mmHg0.580.34<0.0001
FVC L0.560.31<0.0001
PI,max cmH2O0.430.19<0.01
Pa,CO2 mmHg−0.400.16<0.02
  • IC: inspiratory capacity

  • FEV1: forced expiratory volume in one second

  • Pa,O2: arterial oxygen partial pressure

  • FVC: forced vital capacity

  • PI,max: maximal inspiratory pressure

  • Pa,CO2: arterial carbon dioxide partial pressure