外源性肺表面活性物质对体外循环后呼吸功能不全的保护作用和机制探讨

The protective effect of exogenous pulmonary surfactant on respiratory insufficiency after cardiopulmonary bypass

目的：探讨外源性肺表面活性物质（ＰＳ）对体外循环（ＣＰＢ）心内直视手术后呼吸功能不全的保护作用及其机制。方法：选择室间隔缺损伴肺动脉高压手术病儿２４例，随机分为对照组和用药组各１２例；用药组于术前和主动脉开放前经气管插管注入天然猪肺ＰＳ（总量１５０ｍｇ／ｋｇ），对照组注入等量生理盐水。测定各组围ＣＰＢ期肺动态顺应性和呼吸指数，气管插管维持时间。动物实验用小型猪２０头，对照组和用药组各１０头；对实验动物左右心房血液中中性粒细胞计数，ＴＮＦα和ＭＤＡ的含量，肺组织含水量和超微结构进行观察。结果：体外循环术后各时点用药组肺动态顺应性显著高于对照组（Ｐ＜０．０５～０．０１）；呼吸指数显著低于对照组（Ｐ＜０．０１）。临床病儿对照组气管插管维持时间为１３．７５小时，而用药组为８．８７小时（Ｐ＜０．０１）。动物实验与对照组相比较，外源性ＰＳ明显抑制中性粒细胞和血小板的肺内隔离，抑制肺内趋化因子ＴＮＦα的释放，减少脂质过氧化物的终产物ＭＤＡ的产生，且病理形态学证实肺损伤的程度明显减轻。结论：预防性应用外源性天然肺表面活性物质对体外循环术后呼吸功能不全有明显的保护作用。

Aim:To study the protective effect and its mechanism of exogenous plumonary surfactant(PS) on respiratory insufficiency after cardiopulmonary bypass(CPB).Clinical material and method:24 childen with VSD associated with pulmonary hypertension undewent open heart surgery under CPB.The patients were randomly divided into two groups:control group and PS group.In the PS groups,exogenous natural porcine PS(150mg/kg) was dropped into the intracheal tube before operation and before removing the aortic clamp.Equal amount of normal saline was given in the control group.Lung compliance and respiratory index;blood neutrophils count,TNF α,MDA,from the right and left atrium;lung fluid volume,lung ultrastructure in both groups were determined perioperatively.Results:The dynamic compliances of the lung in PS group was higher than that in control group(P<0.05-0.01).The respiratory index in PS group was significantly lower than that of in control groups(P<0.01) after CPB.The intube time in PS group was 8.87 hours,much shorter than that in control group(13.75 hours,P<0.01).The histological examination of the lung under electron microscope confirmed that the degree of pulmonary injury was significantly decreased in PS group.Conclusion:The exogenous natural PS has markedly protective effect on respiratory insufficiency after CPB.