Head and Neck Positional Change Causes the Alteration in Endotracheal Cuff Pressure / 대한마취과학회지

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.

The Sealing Volume and Pressure of the Bronchial Blocker Cuff of Univent(R) Tubes / 대한마취과학회지

BACKGROUND: The manufacturer has recommended that 6-7 ml of air be used to seal the bronchial blocker cuff of Univent tubes high pressure type. However overinflation of the cuff might result in pressure damage to mucosa. This study was performed to evaluate the appropriate sealing volume and pressure of the bronchial blocker cuff. METHODS: Univents were inserted in 26 patients. The bronchial blocker was connected to a pressure gauge and the cuff was inflated by 0.5 ml increment until the bronchus was sealed in supine and lateral positions under 20-25 mmHg airway pressure. The sealing volume and pressure were recorded. RESULTS: In males, the sealing volume for the left bronchus (3.8 +/- 0.4 ml) was smaller than for the right bronchus (5.4 +/- 1.0 ml) in both positions significantly (p < 0.05). In females, the sealing volume for the left bronchus (2.8 +/- 0.4 ml in both positions) was smaller than the volume for the right bronchus (3.7 +/- 0.8 ml in supine position, 3.9 +/- 0.9 ml in lateral position) significantly (p < 0.05). The sealing volume for females was smaller than for males significantly (p < 0.05), for all sealing pressures, there were no significant differences statistically. CONCLUSIONS: The bronchial blocker of Univent is a high pressure type and the sealing volume is higher for the right bronchus than for the left bronchus. Furthermore the sealing volume is less than the volume which is recommended by the manufacturer.