Static pressures during maximal inspiratory effort and static expiratory compliance
| Parameter | Normal group, seated | Obese group, seated | p Value | Normal group, supine | Obese group, supine | p 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) | 0.206 | 28.5 (22.0) | 16.4 (13.7) | 0.180 |
| Pdi at TLC (cm H2O) | 54.1 (19.5) | 50.5 (17.6) | 0.682 | 64.8 (24.0)* | 52.7 (16.7) | 0.235 |
| PL,max at TLC (cm H2O) | 32.2 (2.8) | 23.7 (7.4) | 0.033 | 31.7 (2.5) | 25.3 (7.5) | 0.028 |
| PImax at FRC (cm H2O) | 109.9 (41.8) | 72.2 (30.1) | 0.043 | 96.7 (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) | 0.682 | 4.1 (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) | 0.023 | 6.6 (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.