套管气囊内压与兔气管损伤的关系

Cuff Pressure within Inflating Endotracheal Tube and Tracheal Injury in Rabbits

目的研究套管气囊内压与小儿气管损伤的关系。方法选择4-5月龄的大耳白兔80只,按照套管气囊内压以及放置时间的不同,以随机分组的方式,分为A组（20只兔子。给予气囊内压15 mmHg分别持续充气2、4 h）、B组（30只兔子。给予气囊内压15 mmHg持续充气2 h再分别给予气囊放气10、20、30 min后再次充气2 h,反复3次）、C组（20只兔子。给予气囊内压25 mmHg分别持续充气2、4 h）、D组（10只兔子为对照组）。结果与对照组相比较,A1组（给予15 mmHg压力,维持2 h）,B2组（给予15 mmHg压力,维持2 h,放气20 min,再充气,反复3次）和B3组（给予15 mmHg压力,维持2 h,放气30 min,再充气,反复3次）,拔管24 h后气管壁黏膜层出现少量纤毛细胞脱离,基底细胞基本完整,黏膜下有少量红细胞渗出,软骨基本完整（HE染色光镜下）;21 d后,气管组织结构未见异常。A2组（给予15 mmHg压力,维持4 h）,B1组（给予15 mmHg压力,维持2 h,放气10 min,再充气,反复3次）和C组（给予25 mmHg压力,维持2、4 h）,拔管24 h后出现气管壁黏膜层纤毛细胞大面积脱落,基底细胞部分破坏,黏膜下层出现水肿,有红细胞渗出及炎性细胞浸润,软骨受损（HE染色光镜下）;21 d后,气管上皮细胞缺失,未被正常的黏膜上皮所修复,黏膜下可见炎性细胞及红细胞,软骨受损。病变程度随气囊内压的增大及充气放置时间的延长而加重。结论对小儿行气管插管术或气管切开术后,套囊内压维持在15 mmHg为宜,充气时间不超过2 h,且放气时间不少于20 min,可减轻套囊对气管组织结构的损伤。

Objective To investigate the relationship between the cuff pressure within inflating endotracheal tube and the tracheal injury in child. Methods According to the pressure of the cuff and pressing time, 80 healthy rabbits of 4-5 months age were divided into 4 groups at random： Group A（20 healthy rabbits ： The cuff pressure is 15 mmHg for 2, 4 hours）, Group B（30 healthy rabbits： The cuff pressure is 15 mmHg. After 2 hours, the cuff is disinflated 10, 20, and 30 minutes and then it is reinflated again. Repeat the steps 3 times）, Group C（20 healthy rabbits： the cuff pressure is 25 mmHg for 2, 4 hours）, Group D（10 healthy rabbits）： control. Results Compared with the control group, Group A1（15mmHg for 2 hours）, Group B2（15mmHg for 2 hours, disinflated 20 minutes and repeated 3 times） and Group B3（15mmHg for 2 hours, dissimilated 30 minutes and repeated 3 times） showed a slight trauma of pseudostratified ciliated columnar epithelium cells after 24 hours. After 21 days, Organizational structures of the trachea returned to the original shape. Group A2（15mmHg for 4 hours）, Group B1（15mmHg for 2 hours, disinflated 10 minutes and repeated 3 times） and Group C（25mmHg for 2, 4 hours） manifested pseudostratified ciliated columnar mucosal epithelium completely was off, submucosa had a lot of red blood cells, cartilages seriously were broken and the trachea structure was not continuous after 24 hours. After 21 days, the above pathological changes did not return to normal. Submucosa had red blood cells, cartilages seriously were broken and the trachea structure was not continuous. Conclusion Due to trachea intubation and tracheotomy of child, minimal damage to the tube cuff pressure is maintained at 15 mmHg, and pressing time is less than 2 hours. For a long time with cuff, it is the safest that the disinfating time is 20 minutes at least.