机械通气及表面活性物质干预对肺泡毛细血管膜通透性的影响

Effects of ventilation and surfactant perturbation on alveolocapillary permeability

目的 研究大潮气量机械通气（ ＬＴＶＶ）及琥珀酸二辛酯磺酸钠盐（ＤＯＳＳ） 致肺泡表面活性物质功能障碍对家兔肺泡毛细血管膜通透性的影响和对肺组织提取液（ＬＴＥ） 表面张力的影响。方法 用肺泡毛细血管对９９ｍ 锝人体血清白蛋白（９９ｍＴＣＨＳＡ）通透性指数表示肺泡表面活性物质功能障碍及ＬＴＶＶ后肺泡毛细血管膜通透性特性。对对照组、ＬＴＶＶ、ＤＯＳＳ及ＤＯＳＳ＋ ＬＴＶＶ四组的通透性指数、湿肺重量、呼吸系统动态顺应性（Ｃｄｙｎ）、动脉血气及ＬＴＥ表面张力进行了测定。结果 实验期间四组动物Ｃｄｙｎ 及血气均维持稳定。四组动物的湿肺重量分别为（１－８５ ±０－１６）ｇ／ｋｇ，（２－５０ ±０－２７）ｇ／ｋｇ，（１－８８ ±０－１２）ｇ／ｋｇ 及（２－６５±０－１３）ｇ／ｋｇ。ＬＴＶＶ与ＤＯＳＳ＋ ＬＴＶＶ组比较，差异有显著性（ Ｐ＜０－０１ ） 。肺泡毛细血管通透性指数分别为０－１０±０－０４，０－７２±０－１４，０－１３±０－０３ 及０－７９±０－１７。ＬＴＶＶ及ＤＯＳＳ＋ＬＴＶＶ组也明显增高（Ｐ＜０－０１ ）。四组间ＬＴＥ表面张力无任何差异。结论 本研究结果提示，肺泡毛细血管通透性增高、肺水肿及肺损伤是由ＬＴＶＶ

Objective To investigate the effects of large tidal volume ventilation (LTVV) and surfactant dysfunction induced with dioctyl sodium sulphoccinate (DOSS) on alveolocapillary permeability , and on the surface tension of lung tissue extract (LTE) Methods The permeability index of tecthnetium 99m labelled human serum albumin ( 99m Tc HSA ) was used to characterize the alveolocapillary permeability after LTVV and surfactant dysfunction permeability index, dynamic respiratory compliance (Cdyn), arterial blood gas (ABG), wet lung weight and surface tension of LTE were measured in four groups of rabbits: (1) controls; (2) LTVV; (3) DOSS; and (4) DOSS+LTVV Results Cdyn and ABG were stable throughout the experiment in all groups The wet lung weight was (1 85±0 16) g/kg , (2 50±0 27) g/kg, (1 88±0 12) g/kg and (2 65±0 13) g/kg in four groups respectively It was significantly increased in LTVV and DOSS+LTVV groups compared with controls and DOSS ( P <0 01) The permeability index was 0 10±0 04, 0 72±0 14, 0 13±0 03 and 0 79±0 17 in four groups respectively There was a significantly increased permeability index in LTVV and DOSS+LTVV groups compared with controls and DOSS ( P <0 01) There was no difference of surface tension of LTE among all groups Conclusions The results of this study suggest that the increased alveolocapillary permeability, pulmonary edema and lung injury are induced by LTVV rather than DOSS The mechanisms of HSA transferring alveolocapillary membrane from different directions are different