Anthropometric characteristics and pulmonary function data of the normocapnic and hypercapnic patients with chronic obstructive pulmonary disease
| Normocapnic patients | Hypercapnic patients | p-value | |
| Subjects n | 9 | 6 | |
| Age yrs | 66.9±3.0 | 66.5±3.4 | 0.93 |
| Body mass index kg·m−2 | 24.7±1.7 | 29.5±2.5 | 0.12 |
| FEV1 L | 0.94±0.06 | 0.80±0.13 | 0.39 |
| FVC L | 2.46±0.14 | 2.00±0.27 | 0.12 |
| FEV1/FVC | 37.9±1.4 | 39.2±3.8 | 0.72 |
| FRC L | 7.12±0.58 | 6.92±0.45 | 0.81 |
| RV L | 6.39±0.61 | 6.20±0.40 | 0.82 |
| TLC L | 9.20±0.60 | 8.28±0.40 | 0.28 |
| pH | 7.41±0.01 | 7.38±0.01 | <0.01 |
| Pa,CO2 mmHg | 39.9±0.6 | 52.4±1.6 | <0.001 |
| Pa,O2 mmHg | 69.6±2.0 | 57.7±4.0 | 0.01 |
| Arterial bicarbonate content, mEq·L−1 | 25.6±0.6 | 31.2±1.1 | <0.001 |
| Edyn cmH2O·L−1 | 4.37±0.70 | 9.62±1.66 | <0.05 |
| Edyn/Pdi,max L−1 | 25.6±0.6 | 31.2±1.1 | <0.001 |
Values are expressed as mean+se
FEV1: forced expiratory volume in one second
FVC: forced vital capacity
FRC: Functional residual capacity
RV: residual volume
TLC: total lung capacity
Pa,CO2: arterial carbon dioxide tension
Pa,O2: arterial oxygen tension
Edyn: dynamic elastance
Pdi,max: maximal transdiaphragmatic pressure