Effectiveness of the endotracheal tube cuff on the trachea: physical and mechanical aspects

Introduction

The inflation pressure of the endotracheal tube cuff can cause ischemia of thetracheal mucosa at high pressures; thus, it can cause important tracheal morbidityand tracheal microaspiration of the oropharyngeal secretion, or it can even causepneumonia associated with mechanical ventilation if the pressure of the cuff isinsufficient.

Objective

In order to investigate the effectiveness of the RUSCH® 7.5 mm endotracheal tubecuff, this study was designed to investigate the physical and mechanical aspectsof the cuff in contact with the trachea.

Methods

For this end, we developed an in vitro experimental model to assess the flow ofdye (methylene blue) by the inflated cuff on the wall of the artificial material.We also designed an in vivo study with 12 Large White pigs under endotrachealintubation. We instilled the same dye in the oral cavity of the animals, and weanalyzed the presence or not of leakage in the trachea after the region of thecuff after their deaths (animal sacrifice). All cuffs were inflated at thepressure of 30 cmH₂O.

Results

We observed the passage of fluids through the cuff in all in vitro and in vivoexperimental models.

Conclusion

We conclude that, as well as several other cuff models in the literature, theRUSCH® 7.5 mm tube cuffs are also not able to completely seal the trachea and thusprevent aspiration of oropharyngeal secretions. Other prevention measures shouldbe taken.