| Factors | Adjusted OR (95% CI) | P value |
| Age | 0.96 (0.77 - 1.2) | 0.71 |
| Height | 0.95 (0.80 - 1.12) | 0.51 |
| Weight | 1.84 (0.92 - 3.69) | 0.08 |
| Gender | 0.57 (0.19 - 1.52) | 0.24 |
| Operation time | 0.99 (0.99 - 1.01) | 0.76 |
| Use of CPB | 0.82 (0.27 - 2.8) | 0.82 |
| Tracheal tube diameter | 0.58 (0.11 - 2.13) | 0.33 |
| Use of uncuffed tube | 0.31 (0.10 - 0.93) | 0.04 |