The Effect of Positive End-Expiratory Pressure on Air Leakage: Comparison of Cuff Designs

Abstract

Background: Recently developed taper-shaped cuffs (TG cuffs) of endotracheal tubes (ETTs) are known to have a more potent sealing effect than cylindrical high-volume low-pressure cuffs (HL cuffs) of conventional ETTs. The aim of this study was to compare TG cuffs with HL cuffs of ETTs in a bench-top model with regard to air leakage under various positive end-expiratory pressures (PEEP). Methods: HL cuffs and TG cuffs made from PVC were included (HL group vs. TG group). A model trachea with an internal diameter (ID) of 22 mm was attached to a test lung. The test lung was ventilated using an anesthesia respirator with volume controlled mode and PEEPs of 0, 5, 10, or 15 cm H2O. Using spirometry, percentages of expired to inspired tidal volumes (TVe/i) were calculated as a measure of air leakage. Results: With regard to PEEPs, the HL group showed significantly higher air leakage compared to the TG group (p < 0.0001), and a higher PEEP resulted in greater air leakage (p < 0.0001). Air leakage with higher PEEP was greater in the HL group than in the TG group at ID 7.0 mm and 7.5 mm (p = 0.0467, p = 0.0045) Conclusions: This study shows the superior sealing ability of the TG cuff during ventilation at various PEEPs.