肺表面活性物质治疗急性呼吸窘迫综合征的实验研究

目的：观察外源性肺表面活性物质（ＰＳ）对实验性急性呼吸窘迫综合征（ＡＲＤＳ）的疗效。方法：１８只新西兰白兔油酸诱发ＡＲＤＳ后，９只在机械通气基础上经气道滴入猪ＰＳ（１００ｍｇ／ｋｇ，为ＰＳ组），另外９只给于单纯机械通气作为对照组，均观察４小时。于动物实验的基础状态、治疗前及治疗后１小时、２小时、４小时测定肺功能残气量（ＦＲＣ）、动脉血气和肺泡动脉血氧分压差〔Ｐ（Ａ－ａ）Ｏ２〕。实验结束时观察肺病理形态并测定肺泡容积密度（ＶＶ）。结果：治疗后，对照组ＦＲＣ和动脉血氧分压（ＰａＯ２）／氧浓度（ＦｉＯ２）比值（ＯＩ）呈下降趋势，而ＰＳ组ＦＲＣ和ＯＩ明显高于治疗前和同时间点的对照组（Ｐ＜０．０５或Ｐ＜０．０１），Ｐ（Ａ－ａ）Ｏ２明显低于治疗前和同时间点的对照组（Ｐ＜０．０５或Ｐ＜０．０１）。病理形态观察见对照组广泛性肺不张、肺泡和间质水肿、出血和炎性细胞浸润，ＰＳ组上述改变较轻，ＶＶ增加（Ｐ＜０．０１）。结论：外源性肺表面活性物质对兔油酸型ＡＲＤＳ模型有一定的治疗效果

Effects of exogenous pulmonary surfactant on acute respiratory distress syndrome in rabbits

Objective:To assess the efficacy of a porcine pulmonary surfactant (PS) on experimental acute respiratory distress syndrome (ARDS).Methods:Adult rabbits were anaesthetized,tracheostomized and mechanically ventilated.Oleic acid was infused intravenously to induce ARDS and then ventilated for another 4 hours.Animals were treated with either intratracheal PS (100 mg/kg, n =9) or without PS (control, n =9).Lung functional residual capacity (FRC),blood gas values and alveolar arterial blood oxygen tension difference P (A-a) O 2 were measured and followed by lung histological and morphometric examination.Results:After treatment with PS,FRC and PaO 2/FiO 2 ratio were significantly improved,while P (A-a) O 2 was markedly decreased compared to baseline values or control group ( P <0 05 or P <0 01).In the control group,lung histological findings included extensive atelectasis,intraalveolar and interstitial edema,hemorrhage and inflammatory cell infiltration,while those pathologic changes were relatively minor in the PS group.Moreover,morphometric data revealed that animals in the PS group had larger and more regular expanded alveolar space than that in the controls ( P <0 01).Conclusions:Exogenous surfactant has therapeutic effects on oleic acid induced ARDS in rabbits.