Characterization of Pressure–Volume Dynamics in Cuffed Endotracheal Tubes for Effective Airway Pressure Management: A Benchtop Study

Cuffed endotracheal tubes (ETTs) are widely used in critical care settings to provide life-saving mechanical ventilation to patients undergoing surgery or experiencing respiratory distress. However, improper inflation and inadequate monitoring of ETT cuff pressure can lead to postoperative complications such as sore throat, tracheal mucosal injury, and ventilator-associated pneumonia. The recommended cuff pressure range to reduce the chances of any complications is 20-30 cmH₂O. This study aims to characterize the inflation characteristics of different sizes of commercially available ETT to improve our understanding of their cuff compliance dynamics. Two benchtop tests were performed: (1) unrestricted inflation to measure intracuff pressure, inflation volume, and cuff diameter of the ETT, and (2) restricted inflation within a rigid tracheal analog to capture the relationship between intracuff pressure and tracheal wall contact pressure. Using volume and pressure data from these tests, cuff compliance was calculated to measure each cuff’s inflation characteristics. In comparing data from both tests, it was found that the cuff compliance is higher for high-volume cuffs than medium-volume cuffs in the unrestricted tests, but is found to be higher for medium-volume cuffs in the restricted tests. Unrestricted data also revealed significant manufacturing differences across cuff sizes, with no uniform pattern between sizes of either cuff type. These findings highlight critical differences in inflation characteristics between ETT types and sizes, underscoring the dangers of generalizing ETT behavior and emphasizing the importance of continuous intracuff pressure monitoring to reduce the risk of complications and improve patient care.