Cuff induced tracheal injury in dogs following prolonged intubation.

As the newer high volume low pressure endotracheal tube cuffs have replaced the high pressure cuffs commonly used in the past, there has been a marked decline in the incidence of severe complication due to cuff injury. Studies have shown, however, that the respiratory epithelium of the trachea at the cuff site undergoes squamous metaplasia following prolonged intubation with low pressure cuffs. An experimental model utilizing the canine trachea has been developed to study cuff induced squamous metaplasia and the present study was undertaken to determine the effect of the induced squamous metaplasia on tracheal mucous velocity as well as to determine whether the induced epithelial changes are reversible following removal of the cuffed tube.