Distribution of airway pressure opening in the lungs measured with electrical impedance tomography (POET): a prospective physiological study.

Summary

In 36 mechanically ventilated AHRF patients, EIT during low-flow insufflation demonstrated heterogeneous, regional airway opening pressures; 25% showed elevated AOP, indicating airway closure above applied PEEP. The pressure-slope pattern during insufflation aligned with regional differences, supporting physiologic detection of airway closure distribution rather than a single global threshold.

Key Findings

• In 36 AHRF patients, EIT during low-flow insufflation revealed regional heterogeneity of airway opening.
• Approximately 25% (9/36) exhibited elevated airway opening pressure (AOP), implying airway closure above applied PEEP.
• Changes in the pressure slope during low-flow insufflation corresponded to regional AOP variations, enabling physiologic detection of heterogeneity.

Clinical Implications

Consider assessing regional airway closure when titrating PEEP in AHRF; patterns of low-flow pressure slope and EIT maps may help avoid under-recruitment or overdistension and personalize recruitment strategies.

Limitations

• Single-center study with a modest sample size (n=36)
• Physiologic endpoints without direct linkage to clinical outcomes

Future Directions

Test EIT-guided PEEP/recruitment protocols in randomized trials to assess impacts on oxygenation, ventilator-induced lung injury, and clinical outcomes.