The compliance characteristics of the Portex Soft-Seal cuff improves seal against leakage of fluid in a pig trachea model

A high volume low pressure (HVLP) cuff does not protect the lower airway from contamination by material leaking along longitudinal folds within the cuff wall [1]. This is a major factor in the pathogenesis of ventilator associated pneumonia [2]. The combination of shape and high compliance of the Portex Soft-Seal cuff might eliminate the folds in the cuff walls circumferentially for a portion of the cuff and prevent leakage. We have tested the Soft-Seal cuff in a pig trachea model to establish whether protection against leakage is better than that afforded by standard HVLP cuffs.

Method

The Portex Soft-Seal, Mallinckrodt Hi-Lo, Sheridan Preformed and Portex Profile size 8mm internal diameter HVLP cuffed tracheal tubes were assessed for leakage of dye placed in the subglottic space to the trachea in a benchtop ventilation model and in six isolated pig tracheas. All cuffs were inflated at 30 cmH₂O pressure.

Results

There was no leakage in the ventilation model or in the pig tracheas with the Portex Soft-Seal group, but rapid leakage occurred in all the pig tracheas for the standard HVLP cuffs.

Conclusion

This benchtop study suggests that the improved HVLP cuff compliance characteristics and shape of the Portex Soft-Seal cuff might be beneficial in the prevention of leakage of fluid to the lungs known to occur with HVLP cuffs.

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