Cardiopulmonary exercise test (CPET) peak respiratory responses comparing extremely preterm (EP) children and control children
| Mod/sev BPD (mean±SD) | No/mild BPD (mean±SD) | Control (mean±SD) | |
|---|---|---|---|
| RR baseline (breaths/min)* | 23.0±4.6 | 20.2±4.7 | 20.6±5.2 |
| RR peak (breaths/min) | 48.0±12.8 | 46.9±10.9 | 47.5±12.4 |
| VT/kg baseline (mL/kg)* | 12.2±4.0 | 14.9±6.3 | 13.4±5.1 |
| VT/kg peak (mL/kg)† | 25.7±7.5 | 31.9±5.8 | 29.5±6.5 |
| VE/kg baseline (mL/kg/min) | 266±101 | 275±91 | 250±90 |
| VE/kg peak (mL/kg/min)* | 1393±428 | 1631±431 | 1433±378 |
| Inspiratory capacity baseline (L) | 1.75±0.56 | 1.74±0.74 | 1.67±0.58 |
| Inspiratory capacity peak (L) | 1.84±0.47 | 1.85±0.68 | 1.94±0.68 |
| SpO2 baseline (%) | 97.5±2.9 | 97.7±2.7 | 98.3±1.2 |
| SpO2 peak (%) | 94.3±4.9 | 95.2±4.7 | 95.3±4.9 |
| PETO2 peak (mm Hg) | 103.0±4.8 | 103.8±4.9 | 102.1±10.1 |
| PETCO2 peak (mm Hg) | 35.6±4.1 | 35.6±3.9 | 36.1±3.8 |
| VE/VO2 slope | 27.9±3.3 | 27.4±2.7 | 26.4±2.8 |
| VE/VCO2 slope* | 30.5±3.8 | 28.9±2.9 | 28.6±3.2 |
| BR (%)* | 18.5±23.6 | 15.5±20.9 | 24.6±16.9 |
| Expiratory flow limitation (n, %)* | 16/34 (47%) | 16/49 (33%) | 14/59 (24%) |
| End exercise—dyspnoea | 4.0±2.8 | 4.4±2.2 | 3.8±2.4 |
| End exercise—RPE | 6.0±2.5 | 5.6±2.4 | 5.0±2.7 |
*p<0.05.
†p<0.001.
Post hoc ANOVA one-way comparisons (mean±SE).
RR baseline: mod/sev BPD 2.8±1.0 breaths/min>no/mild BPD*.
VT/kg baseline: mod/sev BPD 2.7±1.1mL/kg<no/mild BPD*.
VT/kg peak: mod/sev BPD 6.2±1.4 mL/kg<no/mild BPD†; mod/sev BPD 3.8±1.3 mL/kg<control*; no/mild EP 3.8±1.3 mL/kg>control*.
VE/kg peak: mod/sev BPD 233±88 mL/kg/min<no/mild BPD*.
VE/VCO2 peak: mod/sev BPD 1.94±0.69<Control*.
BR: no/mild BPD 9.0±3.8% <control*.
ANOVA, analysis of variance; BPD, bronchopulmonary dysplasia; BR, breathing reserve; mod/sev, moderate/severe, PETCO2, end tidal carbon dioxide tension; PETO2, end tidal oxygen tension; RPE, rating of perceived exertion; RR, respiratory rate; SpO2, oxygen saturation pulse; VCO2, carbon dioxide uptake; VE, minute ventilation; VO2, oxygen uptake; VT, tidal volume.