| Airway device size | New scope sizes |
|---|---|
| ETT 3.5 | < 2.7 |
| ETT 5.5 | 2.7 |
| ETT 6.5 | 2.7 |
| ETT 8.0 | 5.3 |
| ETT 9.0 | 7.3 |
| ETT 10.5 | 8.7 |
ETT- Endotracheal Tube
Table adapted from:
Brimacombe J, Dunbar-Reid K. The effect of introducing fibreoptic bronchoscopes on gas flow in laryngeal masks and tracheal tubes. Anaesthesia. 1996 Oct;51(10):923-8