Table 3—

Effect of different patterns of respiratory muscle weakness on carbon monoxide transfer

ControlssCMWUDW/BDWIMWCMW
KCO % pred89.3±8.7115.3±7.9*114.1±15.5*130.2±23.2*85.5±9.4#,§
TL,CO % pred95.2±8.280.0±7.7*86.2±8.666.2±13.2*,#,¶58.0±11.9*,#,¶
VA % pred108.1±8.070.3±4.9*79.9±11.0*55.4±14.4*,#,¶71.9±14.6*
  • Data are presented as mean±sd

  • sCMW: normal subjects simulating combined inspiratory and expiratory muscle weakness

  • UDW/BDW: isolated unilateral and bilateral diaphragm weakness

  • IMW: generalised inspiratory muscle weakness

  • CMW: combined inspiratory and expiratory muscle weakness

  • KCO: carbon monoxide transfer coefficient

  • % pred: percentage of predicted standard reference value

  • TL,CO: transfer factor of the lung for carbon monoxide

  • VA: alveolar volume

  • *: significant difference from control group, p<0.05

  • #: significant difference from sCMW group, p<0.05

  • : significant difference from UDW/BDW group, p<0.05

  • §: significant difference from IMW group, p<0.05. The KCO, TL,CO and VA in the stimulated CMW group are expressed as percentage of the values obtained during standard test CO transfer measurement at TLC