Table 4

Static pressures during maximal inspiratory effort and static expiratory compliance

ParameterNormal group, seatedObese group, seatedp ValueNormal group, supineObese group, supinep Value
Poes at TLC (cm H2O)−42.8 (10.9)−34.9 (10.5)0.140−43.3 (13.9)−42.2 (10.7)0.846
Pgas at TLC (cm H2O)28.9 (25.0)18.1 (10.9)0.20628.5 (22.0)16.4 (13.7)0.180
Pdi at TLC (cm H2O)54.1 (19.5)50.5 (17.6)0.68264.8 (24.0)*52.7 (16.7)0.235
PL,max at TLC (cm H2O)32.2 (2.8)23.7 (7.4)0.03331.7 (2.5)25.3 (7.5)0.028
PImax at FRC (cm H2O)109.9 (41.8)72.2 (30.1)0.04396.7 (32.9)*55.2 (26.0)**0.009
CL,stat slope 50–60%pred TLC (%pred TLC/cm H2O)7.0 (3.4)6.1 (5.0)0.6824.1 (2.0)*3.6 (2.2)*0.617
CL,stat slope 60–70%predTLC (%pred TLC/cm H2O)8.4 (5.1)3.8 (1.7)0.0236.6 (4.8)2.9 (1.2)*0.040
  • Pressures during full inflation to TLC (IC manoeuvre) and PImax manoeuvre at FRC in obese and normal group, seated and supine. Obese subjects poorly performed the PImax manoeuvres, particularly when supine. The sixth and seventh row are estimates of expiratory static lung compliance (CL,stat) over a given range of volume. The mid-range slope between 60 and 70% of TLC could not be measured in one of the obese subjects.

  • *p<0.05, **p<0.01, ***p<0.001 for the comparison of associated changes with posture.

  • FRC, functional residual capacity; IC, inspiratory capacity; TLC, total lung capacity.