Injury of cilia induced by tracheal tube cuffs.

Eighteen mongrel dogs underwent endotracheal intubation with large residual volume, low pressure cuffs. The cuffs were inflated at 20 centimeters of water for a period of four hours. Mucociliary clearance studies and tracheal biopsies were performed immediately following, and three, seven and 14 days after, cuff deflation. Severe ciliary injury was observed on scanning electron micrographs examined immediately and three days after cuff deflation, even though the cuffs were inflated at extremely low pressure for short periods. An appreciable delay in mucociliary clearance was shown to correlate directly with the severity of histologic injury. The morphologic and functional alterations in the cilia due to compression were completely reversible after two weeks.