关键词: 气管黏膜损伤, 气管狭窄, 肉芽增生, 套囊压, 气管插管

Abstract:

Objective To investigate the effects of different degrees of cuff pressures and different intubation states on the morphology and structures of the tracheal intima in the adult rabbits， and to provide a reference for clinical tracheal intubation cuff pressure management. Methods Thirty-two New Zealand white rabbits were randomly divided into healthy state intubation group （HSI group）（n=16） and hemorrhagic shock intubation group （BLSI group）（n=16）. The hemorrhagic shock model of the rabbits in BLSI group was established. Each group was further divided into four subgroups according to cuff pressure： 30 cmH₂O （P30 cmH₂O， n=4）， 40 cmH₂O （P40 cmH₂O， n=4）， 50 cmH₂O（P50 cmH₂O， n=4）， and 60 cmH₂O（P60 cmH₂O， n=4）. The gross and pathological morphology of the tracheal intima of the rabbits at the cuff compression site in various groups were observed by visual inspection and HE staining. The various histological injury manifestations， including the rate of absence of pseudostratified ciliated columnar epithelium， the amount of inflammatory cell infiltration， the degree of submucosal congestion and edema， and submucosal hemorrhage of the rabbits in various groups were detected. Results The gross examination results revealed that the tracheal intima at the cuff compression site of the rabbits exhibited varying degrees of paleness， accompanied by peripheral bulging of the trachea； in contrast， non-compressed regions appeared dark red， and the color difference between compressed and non-compressed areas was obvious. Under the condition of the same cuff pressure， the degree of tracheal intima paleness of the rabbits in BLSI group was increased compared with HSI group. Compared with HSI group， the rates of abscence of pseudostratified ciliated columnar epithelium in the tracheal intima of the rabbits in all subgroups in BLSI group were significantly increased （P<0.05）. Compared with 30 cmH₂O pressure group， the rates of abscence of pseudostratified ciliated columnar epithelium in the tracheal intima of the rabbits in 40 cmH₂O， 50 cmH₂O， and 60 cmH₂O pressure groups were significantly elevated （P<0.05）. Compared with HSI group， the rates of inflammatory cell infiltration in the tracheal intima of the rabbits in all subgroups in BLSI group were significantly increased （P<0.05）. Compared with 30 cmH₂O pressure group， the rates of inflammatory cell infiltration in the tracheal intima of the rabbits in 40 cmH₂O， 50 cmH₂O， and 60 cmH₂O pressure groups were significantly increased （P<0.05）. Compared with HSI group， the degrees of tracheal submucosal congestion and edema of the rabbits in all subgroups in BLSI group were significantly increased （P<0.05）. Compared with 30 cmH₂O pressure group， the degrees of tracheal submucosal congestion and edema of the rabbits in 40 cmH₂O， 50 cmH₂O， and 60 cmH₂O pressure groups were significantly increased （P<0.05）.No Grade 0 injury of the rabbits was observed in either group. Conclusion Exceeding the safe upper limit of endotracheal tube cuff pressure results in varying degrees of tracheal intima injury.

Key words: Tracheal mucosal injury, Tracheal stenosis, Granulation hyperplasia, Cuff pressure, Endotracheal intubation