Foam cuffed tracheal tubes: clinical and laboratory assessment.

The efficiency of a foam cuffed tracheal tube has been studied in protecting the pulmonary tree from aspiration of oropharyngeal and gastric contents. Following instillation of methylene blue dye above the cuff, subsequent fibreoptic bronchoscopy revealed no instance of dye staining of the tracheal mucosa. A "bench" study was undertaken subsequently to estimate the likely pressure that the cuff would exert on the tracheal mucosa as a result of elastic recoil properties of the foam. The results suggested that, under normal clinical conditions, the pressure is not likely to exceed a value at which impairment of the mucosal blood supply would occur.