Table 3.
Cardiorespiratory responses, breathing mechanics, and blood gas data at rest, during submaximal exercise, and during peak exercise in patients with an FVC< 3 L (N = 12) and an FVC> 3.8 L (N = 8).
| Rest | Submaximal | Peak | ||||
|---|---|---|---|---|---|---|
| FVC < 3 L | FVC > 3.8 | FVC < 3 L | FVC > 3.8 | FVC < 3 L | FVC > 3.8 | |
| Cardiorespiratory | ||||||
| Work Rate (W) | 0 | 0 | 20 | 20 | 64 ± 16 | 113 ± 38 * * |
| HR (beats/min) | 75 ± 20 | 74 ± 14 | 96 ± 18 | 86 ± 11 | 117 ± 20 | 124 ± 18 |
| HR (%Peak) | 63 ± 9 n=11 | 60 ± 12 | 82 ± 7 | 70 ± 10 * * | - | - |
| HR (%Predicted max) | - | - | - | - | 76 ± 11 | 81 ± 10 |
| VE (L/min) | 10.62 ± 1.72 | 13.70 ± 3.00 * * | 29.48 ± 5.70 | 30.21 ± 3.63 | 50.55 ± 11.13 | 83.24 ± 23.36** |
| VT (L) | 0.64 ± 0.05 | 0.90 ± 0.21 * | 1.01 ± 0.09 | 1.38 ± 0.31 * | 1.18 ± 0.22 | 2.10 ± 0.55 * * |
| Fb (bpm) | 16.5 ± 3.0 | 15.9 ± 5.0 | 29.4 ± 6.7 | 22.6 ± 4.6 * | 44.2 ± 10.5 | 38.0 ± 8.7 |
| VO2 (L/min) | 0.21 ± 0.05 | 0.31 ± 0.08 * * | 0.78 ± 0.15 | 0.87 ± 0.20 | 1.18 ± 0.20 | 1.79 ± 0.60 * |
| VO2 (ml/min/kg) | - | - | - | - | 10.70 ± 1.97 | 15.86 ± 4.43 * |
| VO2 (%Peak) | 18 ± 3 | 18 ± 5 | 67 ± 11 | 53 ± 14 * | - | - |
| VO2 (%Predicted) | - | - | - | - | 69 ± 9 | 91 ± 23 * |
| VCO2 (L/min) | 0.17 ± 0.05 | 0.23 ± 0.06 * | 0.67 ± 0.14 | 0.72 ± 0.16 | 1.18 ± 0.30 | 2.00 ± 0.70 * |
| VE/VCO2 (ratio) | 65.2 ± 12.1 | 60.5 ± 13.9 | 44.3 ± 4.0 | 43.2 ± 7.4 | 44.1 ± 5.5 | 41.2 ± 7.9 |
| RER (ratio) | 0.79 ± 0.05 | 0.76 ± 0.07 | 0.86 ± 0.07 | 0.82 ± 0.03 | 1.01 ± 0.12 | 1.12 ± 0.07 * |
| Lactate (mmol) | 1.0 ± 0.5 | 1.6 ± 0.7 * | 2.1 ± 0.9 | 1.9 ± 0.5 | 5.4 ± 1.9 | 8.2 ± 2.7 * |
| RPE (Borg 6–20) | - | - | 11.6 ± 1.9 | 10.1 ± 2.5 | 17.8 ± 1.2 | 17.9 ± 1.1 |
| Breathing Mechanics | ||||||
| EELV (%TLC) | 52 ± 7 | 50 ± 9 | 59 ± 6 | 53 ± 8 | 60 ± 6 n=11 | 58 ± 8 |
| EILV (%TLC) | 69 ± 6 | 64 ± 8 | 82 ± 6 | 73 ± 8 * * | 87 ± 3 n=11 | 88 ± 4 |
| IRV (%FVC) | 58 ± 6 | 58 ± 12 | 33 ± 9 | 43 ± 11 * | 23 ± 5 n=11 | 19 ± 5 |
| ERV (%FVC) | 12 ± 6 | 20 ± 12 | 23 ± 6 | 25 ± 12 | 28 ± 6 n=11 | 32 ± 11 |
| IC (L) | 2.09 ± 0.27 | 3.52 ± 0.78 * * | 1.83 ± 0.32 | 3.31 ± 0.73 * * | 1.75 ± 0.30 | 2.98 ± 0.68 * * |
| EELV (L) | 2.38 ± 0.64 | 3.51 ± 0.81 * * | 2.56 ± 0.54 | 3.72 ± 0.78 * * | 2.70 ± 0.60 n=11 | 4.04 ± 0.77 * * |
| EILV (L) | 3.10 ± 0.66 | 4.47 ± 0.83 * * | 3.58 ± 0.59 | 5.15 ± 0.93 * * | 3.88 ± 0.64 n=11 | 6.22 ± 0.87 * * |
| IRV (L) | 1.38 ± 0.24 | 2.56 ± 0.70 * * | 0.79 ± 0.29 | 1.87 ± 0.56 * * | 0.56 ± 0.16 n=11 | 0.81 ± 0.24 * |
| ERV (L) | 0.29 ± 0.17 | 0.85 ± 0.52 * | 0.55 ± 0.15 | 1.06 ± 0.48 * | 0.66 ± 0.14 | 1.39 ± 0.45 * * |
| VE mech (L/min) | 12.12 ± 2.90 | 15.52 ± 3.87 * | 30.48 ± 5.14 | 30.87 ± 4.70 | 53.27 ± 11.92 | 82.29 ± 20.14 * * |
| Fb mech (bpm) | 17.0 ± 3.8 | 16.5 ± 4.6 | 29.9 ± 6.6 | 22.4 ± 4.7 * | 46.0 ± 12.0 | 39.1 ± 8.0 |
| VT mech (L) | 0.72 ± 0.07 | 0.96 ± 0.20 | 1.04 ± 0.12 | 1.44 ± 0.37 * | 1.18 ± 0.21 | 2.17 ± .62 * * |
| VT mech (%FVC) | 30 ± 4 | 22 ± 4 * * | 44 ± 6 | 33 ± 6 * * | 50 ± 5 | 49 ± 12 |
| VT/TI (L/s) | 0.49 ± 0.12 | 0.63 ± 0.13 * | 1.19 ± 0.18 | 1.20 ± 0.21 | 1.96 ± 0.36 | 2.94 ± 0.74 * * |
| VT/TE (L/s) | 0.34 ± 0.09 | 0.44 ± 0.12 | 0.89 ± 0.18 | 0.92 ± 0.17 | 1.63 ± 0.44 | 2.57 ± 0.62 * * |
| EFL (%VT) | 76 ± 10 n=9 | 65 ± 34 n=6 | 63 ± 21 n=8 | 61 ± 12 n=5 | 54 ± 29 n=10 | 57 ± 20 n=8 |
| VE mech/MVV(%) | 18 ± 5 | 14 ± 4 * | 45 ± 8 | 27 ± 6 * * | 77 ± 12 | 71 ± 10 |
| RPB (Borg 0–10) | - | - | 3.8 ± 1.1 n=9 | 1.9 ± 1.3 * * | 8.6 ± 1.3 | 7.9 ± 2.0 |
| RPU (Borg 0–10) | - | - | 3.2 ± 1.7 n=9 | 1.4 ± 1.4 * | 7.8 ± 1.6 | 6.5 ± 2.4 |
| Blood Gases (n = 19) | ||||||
| PaO2 (mmHg) | 84 ± 6 n=12 | 84 ± 6 n=7 | 85 ± 14 n=11 | 89 ± 9 n=7 | 87 ± 15 n=11 | 99 ± 8 n=7 |
| PAO2 (mmHg) | 100 ± 5 | 103 ± 7 | 103 ± 6 | 105 ± 5 | 110 ± 6 | 118 ± 3 * |
| PaCO2 (mmHg) | 42 ± 3 | 38 ± 4 * | 42 ± 4 | 39 ± 4 | 40 ± 4 | 35 ± 3 * |
| PETCO2 (mmHg) | 45 ± 4 | 41 ± 6 | 45 ± 5 | 43 ± 5 | 40 ± 7 | 37 ± 4 |
| A-aO2 Diff (mmHg) | 16 ± 7 | 19 ± 4 | 19 ± 10 | 16 ± 5 | 24 ± 10 | 21 ± 7 |
| VD/VT (ratio) | 0.39 ± 0.07 | 0.40 ± 0.06 | 0.35 ± 0.05 | 0.34 ± 0.05 | 0.34 ± 0.05 | 0.30 ± 0.07 |
| HbO2 (%) | 95 ± 2 | 95 ± 2 | 94 ± 4 | 96 ± 1 | 94 ± 4 | 96 ± 1 |
| pH | 7.42 ± 0.02 | 7.41 ± 0.02 | 7.40 ± 0.02 n=11 | 7.41 ± 0.01 | 7.40 ± 0.03 | 7.39 ± 0.02 |
Data are mean ± SD. HR, heart rate; VE, minute ventilation; VT, tidal volume; Fb, breathing frequency, VO2, oxygen consumption; VCO2, carbon dioxide elimination; RER, respiratory exchange ratio; RPE, ratings of perceived exertion; EELV, end-expiratory lung volume; EILV, end-inspiratory lung volume; IRV, inspiratory reserve volume; ERV, expiratory reserve volume; ‘mech’, denotes variables reported from the breathing mechanics system, which may not be collected simultaneously with the cardiopulmonary variables; TI, inspiratory time; TE, expiratory time; EFL, expiratory flow limitation; RPB, ratings of perceived breathlessness; RPU, ratings of perceived unpleasantness of breathlessness; PaO2, partial pressure of arterial oxygen; PAO2, partial pressure of alveolar oxygen, PaCO2, partial pressure of arterial carbon dioxide; PETCO2, end-tidal partial pressure of carbon dioxide; A-aO2 Diff, alveolar-arterial difference in PO2; and HbO2, arterial oxygen saturation. Predicted peak VO2 Jones (1988). In cases of missing data, the n is denoted as superscript (for blood gas data, this was due to unsuccessful arterial cannulation and for EFL, there was no EFL present. Significant differences between groups: *P < 0.05; **P < 0.01. Comparisons were not made between conditions (rest, 20 W, Peak).