Table 2. Subgroup analyses of the changes in respiratory mechanics and PaO2/FiO2 in patients with normal or poor preoperative lung function under different PEEP levels.
| Lung function | Group | n | DLV | OLV 0.5 h | OLV 1 h | DLV-End of operation |
|---|---|---|---|---|---|---|
| PaO2/FiO2 | ||||||
| Normal | PEEP5 | 44 | 340.4±92.1 | 189.9±74.5 | 215.4±59.5 | 333.0±118.5 |
| PEEPEIT | 45 | 358.2±99.3 | 250.1±107.0a | 319.0±98.4a | 445.3±133.5a | |
| Poor | PEEP5 | 6 | 299.8±79.1 | 139.3±74.7 | 167.9±72.8 | 385.2±189.7 |
| PEEPEIT | 5 | 350.2±67.0 | 220.9±119.5 | 277.6±87.5b | 453.8±117.7 | |
| Cdyn | ||||||
| Normal | PEEP5 | 44 | 24.8±5.5 | 14.8±5.0 | 16.0±4.7 | 25.3±5.8 |
| PEEPEIT | 45 | 26.8±7.2 | 19.4±6.7a | 21.1±7.6a | 27.4±7.7 | |
| Poor | PEEP5 | 6 | 25.4±5.7 | 12.9±5.4 | 18.8±5.1 | 26.5±5.4 |
| PEEPEIT | 5 | 23.7±6.6 | 18.9±4.8b | 20.3±4.9 | 26.2±4.3 | |
| ΔP | ||||||
| Normal | PEEP5 | 44 | 14.0±4.3 | 18.0±4.1 | 18.4±4.4 | 14.9±4.3 |
| PEEPEIT | 45 | 13.9±3.3 | 14.6±3.2a | 15.9±3.6a | 14.1±2.9 | |
| Poor | PEEP5 | 6 | 14.7±4.5 | 17.7±6.3 | 17.5±6.0 | 15.3±3.1 |
| PEEPEIT | 5 | 16.0±2.8 | 14.0±2.2b | 13.1±4.2b | 15.3±3.3 |
Poor lung function was defined as MVV % or FEV1% <70% of the predicted value. aP<0.05, comparation between the PEEPEIT and PEEP5 in the normal subgroup. bP<0.05, comparation between the PEEPEIT and PEEP5 in the poor lung function subgroup.