TRANSTRACHEAL PRESSURE EXERTED BY ENDOTRACHEAL-TUBE CUFFS

Cuffed endotracheal and tracheostomy tubes are employed clinically to provide an airway in anesthetized and unconscious patients. These tubes are inserted into the trachea and then sealed with an inflatable, balloon-like cuff which surrounds the airway tube. Inflated endotracheal tubes may compress the tracheal mucosa causing ischemic tissue damage. In the present study, finite deformation analysis of the cuff was made assuming a rigid trachea. This solution provided transtracheal pressure as a fraction of the cuff inflation pressure. This ratio was examined at various degrees of contact between the cuff and trachea. Inflation pressure and contact pressures were obtained experimentally for endotracheal tubes inserted into rigid ttransparent cylinders about the size of tracheas. Using these data, it was possible to evaluate the estimates obtained from finite deformation analysis by comparing these estimates with experimentally-recorded data.