Relationship between difference in endotracheal tube cuff area and airway area with minimum cuff pressure for adequate airway sealing: a prospective observational study

It is essential for clinicians to select the appropriate endotracheal tube to ensure effective airway management. However, an unmatched endotracheal tube cuff area to the airway area can lead to air or secretion leakage, even at the recommended cuff pressure of 20-30 cmH₂O. The present multicenter prospective observational study aimed to determine the relationship between the difference in cuff area and airway area with the minimum cuff pressure to avoid airway leakage. Adult patients who underwent mechanical ventilation were assigned into three groups, with a minimum cuff pressure of < 20, 20-30, and > 30 cmH₂O, respectively, in order to have adequate airway sealing. The primary outcome was the difference between the endotracheal tube cuff area and airway area (cuff-airway area difference) that was calculated for the three groups. A total of 284 patients were included, with the mean age of 65.19 (± 14.03) years old. There were 166, 63 and 55 patients who required a minimum cuff pressure of < 20, 20-30 and > 30 cmH₂O, respectively. The mean cuff-airway area difference was 236.00 ± 85.26, 149.70 ± 48.34 and - 12.29 ± 113.0 mm² in the < 20, 20-30, and > 30 cmH₂O groups, respectively. In addition, the simple linear regression analysis revealed a negative linear relationship between the cuff-airway area difference and minimum cuff pressure (Y = -0.1266 × X + 46.50, F = 571.40, p < 0.001). It can be concluded that a significant number of patients require a cuff pressure out of the recommended range (< 20 or > 30 mmH₂O) to have adequate airway sealing. Patients with a lower cuff-airway area difference require a higher minimum cuff pressure to seal the airway.