The supine-to-prone position change induces modification of endotracheal tube cuff pressure accompanied by tube displacement

Study Objectives: To determine whether the supine-to-prone position change displaced the endotracheal tube (ETT) and, if so, whether the displacement related to this change modified ETT cuff pressure. Design: Prospective study. Setting: Operating room of a university hospital. Patients: 132 intubated, adult, ASA physical status 1, 2, and 3 patients undergoing lumbar spine surgery. Interventions and Measurements: After induction of anesthesia, each patient's trachea was intubated. The insertion depth of each ETT was 23 cm for men and 21 cm for women at the upper incisors. In the supine position and after the supine-to-prone position change with the head rotated to the right, the length from the carina to ETT tip and ETT cuff pressure were measured. Main Results: After the supine-to-prone position change, 91.7% patients had ETT tube displacement. Of these, 48% of patients' ETT moved ≥ 10 mm, whereas 86.3% of patients had changes in tube cuff pressure. There was a slight but significant correlation between ETT movement and change in cuff pressure. Depending on the position change, ETT cuff pressure decreased and the ETT tended to withdraw. Conclusions: After the supine-to-prone position change, patients had ETT tube displacement. Such ETT movement may be accompanied by a decrease in cuff pressure.