Time course of changes in the transcutaneous partial pressure of carbon dioxide (Ptco2) in the treatment groups
| (1) The mean change in Ptco2 (mm Hg) | ||||
| Time | High concentration O2mean (SD) | Titrated O2mean (SD) | Difference (95% CI) | p Value |
| 20 min | 2.8 (4.1) | 0.3 (3.6) | 2.5 (1.0 to 4.0) | 0.001 |
| 40 min | 3.0 (4.7) | 0.4 (3.8) | 2.6 (0.9 to 4.3) | 0.002 |
| 60 min | 3.4 (4.5) | 0.8 (4.1) | 2.6 (0.9 to 4.3) | 0.003 |
| (2) The proportion of patients with a rise in Ptco2 ≥4 mm Hg | ||||
| Time | High concentration O2N (%) | Titrated O2N (%) | RR (95% CI) | p Value |
| 20 min | 15 (30%) | 7 (13%) | 2.3 (1.0 to 5.1) | 0.038 |
| 40 min | 21 (42%) | 8 (15%) | 2.8 (1.4 to 5.7) | 0.002 |
| 60 min | 22 (44%) | 10 (19%) | 2.3 (1.2 to 4.4) | 0.006 |