Patients' characteristics and baseline ventilator settings at the beginning of the experimental trial
| Patient no. | Age yrs | pH | Pa,CO2 mmHg | Pa,O2/FI,O2 | FEV1 % pred | FEV1/FVC % | PS cmH2O | PEEPext cmH2O | Initial pressurisation rate cmH2O·s−1 |
| 1 | 74 | 7.31 | 94.30 | 264.00 | 21.00 | 18.00 | 14.00 | 2.00 | 80.00 |
| 2 | 65 | 7.28 | 82.70 | 258.00 | 43.00 | 33.00 | 15.00 | 4.00 | 120.00 |
| 3 | 83 | 7.32 | 77.30 | 190.00 | 18.00 | 25.00 | 14.00 | 2.00 | 60.00 |
| 4 | 56 | 7.34 | 60.70 | 275.00 | 22.00 | 19.00 | 18.00 | 4.00 | 120.00 |
| 5 | 74 | 7.30 | 63.60 | 156.00 | na | na | 16.00 | 4.00 | 60.00 |
| 6 | 78 | 7.25 | 71.50 | 128.00 | 33.00 | 22.00 | 12.00 | 4.00 | 60.00 |
| 7 | 67 | 7.33 | 56.70 | 249.00 | na | na | 15.00 | 2.00 | 80.00 |
| 8 | 68 | 7.29 | 71.70 | 281.00 | na | na | 18.00 | 4.00 | 100.00 |
| 9 | 80 | 7.21 | 93.50 | 222.00 | 28.00 | 37.00 | 14.00 | 5.00 | 58.00 |
| 10 | 77 | 7.16 | 104.20 | 146.00 | 24.00 | 41.00 | 22.00 | 6.00 | 60.00 |
| 11 | 81 | 7.33 | 57.2 | 189.00 | 17.00 | 62.00 | 12.00 | 2.00 | 80.00 |
| 12 | 62 | 7.32 | 83.00 | 219.00 | 13.00 | 19.00 | 13.00 | 3.00 | 30.00 |
| 13 | 71 | 7.34 | 81.00 | 237.00 | na | na | 14.00 | 4.00 | 120.00 |
| 14 | 70 | 7.32 | 53.30 | 243.00 | 42.00 | 44.00 | 14.00 | 4.00 | 80.00 |
| 15 | 61 | 7.29 | 69.5 | 240.00 | 15.00 | 21.00 | 18.00 | 4.00 | 50.00 |
| Mean±sd | 7±7.9 | 7.32±0.01 | 68.8±14 | 226±22.5 | 21.8±14 | 36.5±20.4 | 14.2±2 | 3.4±1 | 77.5±37 |
Arterial blood gases were taken at the time of the episode of acute respiratory failure, necessitating noninvasive ventilation
Pa,CO2: partial pressure of arterial carbon dioxide oxygen
Pa,O2: partial pressure of arterial oxygen
FI,O2: fractional concentration of oxygen
FEV1: forced expiratory volume in one second
% pred: % predicted
FVC: forced vital capacity
PS: pressure support level
PEEPext: external positive end-expiratory pressure
na: not available
kPa=mmHg×0.133