Surfactant supplement for adult respiratory distress

成人呼吸窘迫综合征（ARDS）的病理过程尚不清楚，死亡率高达50-70%。(1)病理过程研究：将外源性表面活性物质与ARDS患者肺水肿液混合，注入未成熟新生兔肺内。当水肿液蛋白/表面活性物质比值从5.6增加到11.2时，肺动态顺应性从1.08（平均值）下降到0.43 ml/cmH_2O/kg（P < 0.05）。我们的结论是呼吸衰竭的原因之一是肺表面活性物质失活的肺水肿，出现在过程中。(2)补充肺表面活性物质治疗急性呼吸窘迫综合征：E.补充外源性表面活性剂（100 mg/kg）可明显逆转大鼠的大肠杆菌内毒素血症，使PaO_2由106 mmHg（平均）提高到400 mmHg以上（P < 0.05），胸片弥漫性浸润消失。我们的结论是，表面活性物质补充可以逆转呼吸衰竭的ARDS。(3)用于补充治疗的人工表面活性剂：将二棕榈酰卵磷脂、不饱和卵磷脂（u-L）、磷脂酰甘油和猪表面活性剂的疏水蛋白以各种比例混合。未成熟幼兔动态肺顺应性，含各组分的混合液为1.24ml/cmH_2O/kg，而不含u-L的混合液为0.79ml/cmH_2O/kg（P < 0.05）。我们得出结论，u-L是表面活性剂活性的一个重要因素。

Pathological process of adult respiratory distress syndrome (ARDS) is largely unknown with 50-70% mortality.(1) Investigation on the pathological process: An exogenous surfactant was mixed with lung edema fluid sampled from ARDS patients, and administered to the lungs of immature newborn rabbits. When the edema fluid protein-to-surfactant ratio increased from 5.6 to 11.2, the dynamic lung compliance of the animals decreased from 1.08 (mean) to 0.43 ml/cmH_2O/kg (P < 0.05). We conclude that a cause of respiratory failure in ARDS is inactivation of pulmonary surfactant by lung edema that appears during the course.(2) Treatment of ARDS by surfactant supplement: Respiratory failure induced by administration of E. Coli endotoxin in rats was largely reversed by supplementation of an exogenous surfactant (100 mg/kg); PaO_2 improved from 106 mmHg (mean) to above 400 mmHg (P < 0.05), and diffuse infiltrates in the chest radiogram disappeared. We conclude that surfactant supplementation can reverse the respiratory failure in ARDS.(3) Artificial surfactant for the supplement therapy: Dipalmitoyl lecithin, unsaturated lecithin (u-L), phosphatidylglycerol and the hydrophobic proteins of porcine surfactant were mixed with various ratios. Dynamic lung compliance of the immature newborn rabbits receiving the mixture consists of all the components was 1.24 ml/cmH_2O/kg (mean), but the value receiving the mixture without u-L was 0.79 ml/cmH_2O/kg (P < 0.05). We conclude that u-L is an important factor for surfactant activity.