From: The effect of high concentration oxygen therapy on PaCO2 in acute and chronic respiratory disorders
 | High concentration | Titrated | Relative risk | P value |
---|---|---|---|---|
 | n (%) | n (%) | (95% CI) |  |
Change in PtCO2 ≥4 mmHg | 36 (50%) | 11 (14.7%) | 3.4 (1.9 to 6.2) | <0.001 |
Change in PtCO2 ≥8 mmHg | 11 (15.3%) | 2 (2.7%) | 5.7 (1.3 to 25.0) | 0.007 |