Cuff pressure of endotracheal tubes after changes in body position in critically ill patients treated with mechanical ventilation.

BACKGROUND In order to avoid microaspiration and tracheal injury, the target for endotracheal tube cuff pressure is 20 to 30 cm H2O. OBJECTIVE To assess the effect of changes in body position on cuff pressure in adult patients. METHODS Twelve orally intubated and sedated patients received neuromuscular blockers and were positioned in a neutral starting position (backrest, head-of-bed elevation 30º, head in neutral position) with cuff pressure at 25 cm H2O. Then, 16 changes in position were performed: anteflexion head, hyperextension head, left and right lateral flexion of head, left and right rotation of the head, semirecumbent position (head-of-bed elevation 45°), recumbent position (head-of-bed elevation 10°), horizontal backrest, Trendelenburg position (10°), and left and right lateral positioning over 30°, 45°, and 90°. Once a patient was correctly positioned, cuff pressure was recorded during an end-expiratory ventilatory hold. The pressure observed was compared with the cuff pressure at the starting position. Values outside the target range (20-30 cm H2O) were considered clinically relevant. RESULTS A total of 192 measurements were performed (12 subjects × 16 positions). A significant deviation in cuff pressure occurred with all 16 changes (P < .05). No pressures were less than the lower limit (20 cm H2O). Pressures were greater than the upper limit (30 cm H2O) in 40.6% of the measurements. In each position, the upper target limit was exceeded at least once. Within-patient variability was substantial (P = .02). CONCLUSION Simple changes in patients' positioning can result in potentially harmful cuff pressures.