Endotracheal cuff pressure identifies inspiratory effort extremes in proof-of-concept study

Esophageal pressure is the reference standard for monitoring inspiratory effort and lung stress during assisted ventilation, but equipment and training requirements limit routine use. In a prospective proof-of-concept study published in Anesthesiology, researchers simultaneously recorded esophageal and endotracheal tube cuff pressures in 30 orally intubated adults. Pressure support was reduced from 15 to 5 cm H2O, and cuff pressure was calibrated using occlusion-induced airway pressure changes.

Across 840 breaths, cuff pressure swings correlated with esophageal pressure swings, with marginal and conditional R² values of 0.772 and 0.949. Mean bias was 0.25 cm H2O, but limits of agreement ranged from −5.42 to 5.92 cm H2O. Areas under the receiver operating characteristic curve were 0.95 and 0.94 for low effort, and 0.93 and 0.82 for high effort, using inspiratory muscle pressure and its pressure-time product per minute, respectively.

With leave-one-out cross-validation, cuff pressure discriminated transpulmonary driving pressure above 20 cm H2O and transpulmonary mechanical power above 12 J/min, with AUCs of 0.89 and 0.88, respectively. These findings suggest potential for bedside identification of potentially injurious respiratory effort and lung stress. However, the small proof-of-concept sample and wide agreement limits constrain interpretation: cuff pressure cannot replace esophageal pressure for precise quantification, and the study does not establish improved clinical outcomes.