肺表面活性物质对胎粪吸入鼠肺功能的影响

Effects of exogenous surfactant on lung function in rats with meconium aspiration

目的 探讨外源性肺表面活性物质(PS)对胎粪吸入鼠肺功能的影响。方法 28只Wistar大白鼠进行人工通气,经气道注入3～4 ml/kg胎粪溶液,PaO2降至20 kPa以下后将动物随机分为4组(每组7只)。A组,气道内注入PS 150 mg/kg(50 mg/ml,3 ml/kg);B组,气道内注入等量生理盐水;C组,用PS稀溶液75 mg/kg(5 mg/ml,15 ml/kg)进行支气管肺泡灌洗,重复2次;D组,用15 ml/kg的生理盐水灌洗双肺。治疗后15 min、30 min、60 min、120 min、180 min采血进行血气分析。180 min后测定各组潮气量,并进行支气管肺泡灌洗(BAL),检测BAL液中总蛋白(TP)和,TNF-α含量。结果治疗后A和C组PaO2均明显升高,而B和D组在治疗后几乎不变,A、C组与B、D组相比,P<0.05。A与C组间差异均无显著性。A和C组的潮气量明显高于B和D组(P<0.05)。A和C组的BAL液中TP含量明显低于B和D组(JP<0.05)。TNF-α含量各组间无差异。结论 补充PS明显改善胎粪吸入鼠肺的氧合和顺应性。PS稀溶液灌洗法优于气道注入法。

Objective To examine the effects of exogenous pulmonary surfactant (PS)on lung function in rats with meconium aspiration.Methods Twenty Wistar rats of both sexes were anesthetized with intraperitoneal pentobarbital 30 mg·kg-1 , tracheotomized and mechanically ventilated (PIP= 16 cm H2O,RR =40 bpm,I:E= 1 : 1, FiO2 = 1.0) . 3-4 ml· kg -1 of saline suspension of human meconium ( 200 mg · ml-1 ) was introduced into trachea. Respiratory failure was induced when PaCO2 < 20 kPa(FiO2 = 1.0) .The animals were then randomly divided into 4 groups of 7 animals each: group A received PS 150 mg· kg-1 (50 mg· ml-1 ,3 ml· kg-1 ) instilled into trachea; group B received normal saline (NS) 3 ml · kg-1 instilled into trachea instead of PS; group C received dilute PS 75 mg·kg-1 (5 mg·ml-1 ,15 ml·kg-1) administered by bronchoalveolar lavage(BAL) ;group C received NS 15 ml·kg-1 administered by BAL. Blood gases were measured 15,30 ,60,120,180 min after treatment. Tidal volume was measured 180 min after treatment and BAL was performed with 40 ml· kg-1 normal saline. The total protein content and TNF-α concentration of BAL fluid were measured. Results ( 1) PaO2 was significantly increased in group A and C as compared with the pretreatment value and was significantly higher than that in group B and D ( P < 0.05). But there was no significant difference in PaO2 between group A and C. (2)The tidal volume was significantly larger in group A and C than that in group B and D. (3)The total protein content in the BAL fluid was significantly less in group A and C than that in group B and D. (4)The was no significant difference in TNF-α concentration of BAL fluid among the 4 groups. Conclusions PS replacement improves lung function in respiratory failure induced by meconium aspiration. Dilute PS administered by bronchoalveolar lavage is more effective than instillation.