what et tube size
1 Manufacturers recommended suction settings. 2  Intermittent suction for 10-15 sec (at 100-150 mmHg). 3  But significantly increases Endotracheal Tube outer diameter (OD) for a given internal diameter (ID). 4  ET with a 7.5 mm ID tube has a 10.2 mm OD, but is 11.2 mm OD with suction port.