Determinants of Tracheal Pressure During Flow-Dependent Positive Expiratory Pressure Therapy
Irene Comelli, Lorenzo Ball, Chiara Robba, Valentina Fassone, Nicolò Antonino Patroniti, Denise BattagliniBackground:
Positive expiratory pressure (PEP) devices facilitate airway clearance, but the determinants of pressure transmission during therapy are not fully understood.
Methods:
In this bench study, a flow-dependent PEP device was tested using tracheostomy tubes with internal diameters of 7, 8, and 9 mm under different oxygen flows (0–15 L/min), tidal volumes (260–886 mL), and breathing frequencies (10–32 breaths/min). Tracheal and airway pressures were measured.
Results:
A total of 486 observations were analyzed. Mean maximum tracheal pressure was 11 ± 7 cm H
2
O for 7 mm and 8 mm tubes and 10 ± 6 cm H
2
O for 9 mm tubes. Oxygen flow was the main determinant of maximum tracheal pressure (
Conclusions:
Tracheal pressure during a flow-dependent PEP therapy was influenced by oxygen flow, ventilatory pattern, and airway diameter. These findings highlight the dynamic behavior of a flow-dependent PEP device and the importance of patient-specific respiratory mechanics during therapy.