Endotracheal tube level is –

"Ideally, the tube tip should be 5 ±2 cm from the carina when the head and neck are in neutral position". ___ Fundamental of anaesthesia Neck flexion causes a 2 cm descent of endotracheal tube towards carina, and neck extension causes a 2cm ascent of trachial tube tip from the carina. Therefore correct position of tip of the tube is :- 5 ±2 cm from carina → When neck is neutral 3 ±2 cm from carina → When neck is flexed 7 ±2 cm from carina → When neck is extended