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，死亡率为50-70%。(1)病理过程的研究：将外源性表面活性物质与ARDS患者的肺水肿液混合，注入未成熟新生兔的肺内。当水肿液中蛋白质与表面活性物质的比例从5.6增加到11.2时，动物的动态肺顺应性从1.08(平均值)下降到0.43ml/cmH2O/kg(P&lt；0.05)。(2)肺表面活性物质补充治疗ARDS：外源性表面活性物质(100 mg/kg)可明显逆转外源性表面活性物质(100 mg/kg)诱导的大鼠呼吸衰竭，PaO_2由106 mm Hg(平均值)升至400 mm Hg以上(P<0.05)，胸片弥漫性浸润物消失。辅助治疗的人工表面活性物质：双磷脂酰卵磷脂、不饱和卵磷脂(u-L)、磷脂酰甘油和猪表面活性物质的疏水蛋白按不同比例混合。未成熟新生兔肺动态顺应性为1.24ml/cmH2O/kg(平均值)，而不含u-L混合液为0.79ml/cmH2O/kg(P&lt；0.05)。由此可见，u-L是影响表面活性的重要因素。

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.