Table 1 Participant Characteristics
Mean (SD) | P | ||
Oxygen N=45a | Air N=45a | ||
Age (years) | 70·4 (10·3) | 72·3 (8·3) | 0.34 |
Age at diagnosis of COPD (years) | 58·6 (12·1) N = 40 | 58·8 (12·2) N = 44 | 0.92 |
BMI (kg/m2) | 27·2 (7·7) | 25·5 (8·9) | 0.33 |
Smoking pack years | 39·3 (31·1) | 51·2 (39·2) | 0.11 |
FEV1 (L) | 0·81 (0·33) N = 35 | 0·85 (0·31) N = 37 | 0.69 |
FEV1% predicted | 35·0 (11·5) N = 35 | 34·0 (11·8) N = 37 | 0.73 |
mMRC | 2·38 (1·09) | 2·33 (1·04) | 0.84 |
Baseline Transcutaneous Data | |||
PtCO2 (mmHg) | 38·0 (7·7) | 37·2 (6·8) | 0.59 |
SpO2 (%) | 92·6 (2·4) | 92·6 (2·3) | 0.93 |
Heart Rate (per minute) | 89·6 (15·7) | 87·0 (16·0) | 0.89 |
Baseline capillary blood gas | |||
pH | 7·42 (0·04) N = 43 | 7·44 (0·03) N = 41 | 0.11 |
PcapCO2 (mmHg) | 40·2 (7·0) N = 43 | 38·5 (5·9) N = 41 | 0.23 |
N/45 (%) | P | ||
Oxygen | Air | ||
Male | 17 (38) | 24 (53) | 0.20 |
Ethnicity | 0.49 | ||
European | 24 (53) | 31 (69) | |
Māori | 7 (16) | 4 (9) | |
Pacific | 5 (11) | 4 (9) | |
Other | 9 (20) | 6 (13) | |
Previous Ventilation (ever) | 12 (27) | 3 (7) | 0.02 |
Previous Ventilation Type | 0.03 | ||
NIV | 10 (22) | 3 (7) | |
Intubation | 2 (4) | 0 (0) | |
Previous hypercapnia | 23 (51) | 17 (38) | 0.29 |
Home Oxygen | 2 (4) | 1 (2) | 0.99 |
Home Nebulisers | 5 (11) | 12 (27) | 0.10 |
Comorbidities | |||
Heart Failure | 8 (18) | 3 (7) | 0.20 |
Asthma | 6 (13) | 2 (4) | 0.27 |
Bronchiectasis | 3 (7) | 4 (9) | 0.99 |