Which of the following statements about the cause and prevention of postintubation tracheal stenosis are correct?

C. In women and smaller men large endotracheal tubes can produce lesions of the glottis and subglottis that can progress to stenosis.

E. A large-volume tracheostomy tube cuff such as that now used on most available tubes can become a high-pressure cuff if filled beyond its resting maximal volume.

DISCUSSION: Use of an endotracheal tube, of course, avoids a stoma and related complications. Cuff lesions, however, are incurred from cuffs on endotracheal tubes, cricothyroidostomy tubes, and tracheostomy tubes. A cuff is the common factor. Endotracheal tubes, on the other hand, cause erosion at the level of the glottis and subglottis, in particular. Although many factors may play some role in the origin of airway stenosis, the principal factor is pressure necrosis of the mucosa, submucosa, and ultimately of the cartilage, with subsequent cicatrization. Large endotracheal tubes do, indeed, cause necrosis and airway injury at narrow areas in the upper airway, at glottic and cricoid levels. Such injuries lead to posterior commissure stenosis, arytenoid fixation, vocal cord erosion and granulomas, anterior commissure stricture, and subglottic circumferential stenosis. While excision of a large amount of tracheal wall can lead inevitably to healing by contraction with narrowing of the tracheal circumference, the most usual cause of stomal stenosis is erosion of the stoma by pressure from the tracheostomy tube. This in turn may relate to leverage by equipment. Additional factors appear to be subsidiary. A large volume, low pressure tracheostomy tube cuff, such as those currently available, if properly constructed, will seal the trachea before it is necessary to stretch the cuff by adding an increasing volume of air. If the cuff is stretched beyond that resting volume, which usually occludes the normal trachea, high pressures will develop because the plastic material from which all of these cuffs are now made is not very extensible. Therefore, the pressure-volume curve rises sharply once the limit of unstretched volume is passed. A low-pressure cuff then becomes a high-pressure cuff.