Moses D, Holm B A, Spitale P, Liu M Y, Enhorning G
Department of Gynecology-Obstetrics, State University of New York, Buffalo.
Am J Obstet Gynecol. 1991 Feb;164(2):477-81. doi: 10.1016/s0002-9378(11)80003-7.
The pathophysiology of meconium aspiration is marked by lung hyperinflation because of airway obstruction, which is often followed by an acute pneumonitis with classic lung injury characteristics. Surfactant dysfunction may contribute to this latter pulmonary pathophysiology. We sought to determine to what extent meconium itself might contribute to a functional surfactant deficiency. Specimens of newborn infants' first meconium were collected and pooled. Serial dilutions of the meconium were then added to various concentrations of calf lung surfactant extract, a mixture with the surface properties of natural surfactant that is used clinically to treat neonatal respiratory distress syndrome, and the dynamic surface activity of these mixtures was studied with a pulsating bubble surfactometer. At surfactant concentrations of less than or equal to 1.5 mg/ml, even 6500-fold dilutions of meconium-inhibited surface tension lowering ability (10 +/- 2 mN/m vs 1 +/- 0.1 mN/m for controls, p less than 0.05). Moreover, this inhibitory activity resided in both the chloroform-soluble and the aqueous phases of meconium and appeared to be additive in nature. However, at sufficiently high concentrations of surfactant, even large amounts of meconium were unable to affect surface tension lowering properties. Thus meconium inhibits surfactant function in a manner that is dependent on the surfactant concentration, suggesting the possible utility of exogenous surfactant therapy in some cases of meconium aspiration.
胎粪吸入的病理生理学特征是由于气道阻塞导致肺过度膨胀，随后常伴有具有典型肺损伤特征的急性肺炎。表面活性剂功能障碍可能导致后者的肺部病理生理学变化。我们试图确定胎粪本身在多大程度上可能导致功能性表面活性剂缺乏。收集并汇集了新生儿的首次胎粪标本。然后将胎粪的系列稀释液添加到不同浓度的小牛肺表面活性剂提取物中，该提取物是一种具有天然表面活性剂表面特性的混合物，临床上用于治疗新生儿呼吸窘迫综合征，并用脉动气泡表面张力仪研究这些混合物的动态表面活性。在表面活性剂浓度小于或等于1.5mg/ml时，即使是6500倍稀释的胎粪也会抑制表面张力降低能力（对照组为10±2mN/m，而处理组为1±0.1mN/m，p<0.05）。此外，这种抑制活性存在于胎粪的氯仿可溶相和水相中，并且似乎具有加和性。然而，在足够高的表面活性剂浓度下，即使大量的胎粪也无法影响表面张力降低特性。因此，胎粪以一种依赖于表面活性剂浓度的方式抑制表面活性剂功能，这表明在某些胎粪吸入病例中外源性表面活性剂治疗可能具有实用性。
