BACKGROUND: Endotracheal tube movement due to changes in the position of the head and neck can affect the intracuff pressure and volume. The alteration in the endotracheal cuff pressure after positional changes of the head and neck were examined and compared to that in the neutral position.

METHODS: 20 adult male patients undergoing orotracheal intubation for endoscopic sinus surgery under general anesthesia were studied. A reinforced tube (internal diameter 8.0 mm) was used for endotracheal intubation. If the initial intracuff pressure exceeded 22 mmHg, it was set to the adjusted intracuff pressure, defined as an intracuff pressure ranging from 15 to 20 mmHg. After recording the adjusted intracuff pressure in the neutral position, repeated measurements after positional changes to 45 degrees flexed, 45 degrees extended and fully rotated positions of the head and neck were taken. The sealing intracuff pressure and volume required for the elimination of audible air-leaks were re-measured in the neutral position, and the changes in the sealing pressure after positional changes of the head and neck were then repeatedly measured. Lastly, the genuine sealing pressure and volume were measured in the flexed, extended and rotated positions.

RESULTS: The adjusted intracuff and sealing pressures were higher in the flexed, extended and rotated positions than in the neutral position (P<0.01). The genuine sealing pressure in flexion and rotation were lower than that in the neutral position (P<0.05). The genuine sealing volumes were smaller in the other positions than in the neutral position (P<0.01).

CONCLUSIONS: It is recommended to make genuine sealing pressure of intracuff pressure under direct pressure monitoring after positional changes of the head and neck.