Ramanathan Rangasamy
Division of Neonatal Medicine, Department of Pediatrics, Women's and Children's Hospital, University of Southern California, Los Angeles, CA 90033, USA.
Neonatology. 2009;95(1):1-5. doi: 10.1159/000151749. Epub 2008 Oct 2.
Respiratory distress syndrome (RDS) is the most common cause of respiratory insufficiency in preterm infants, especially those born at <30 weeks of gestation. Continuous positive airway pressure has been used since the 1970s as a primary mode of treatment for RDS. Surfactant therapy became available in the 1980s and has become the standard care for infants with or at risk for RDS. Surfactant therapy has been shown to decrease air leaks, neonatal and infant mortality as well as cost among survivors. Natural surfactants derived from animal sources containing surfactant proteins B (SP-B) and C (SP-C) as well as synthetic surfactants with functional SP-B- or SP-C-like protein mimics have been extensively evaluated in preterm neonates with or at risk for RDS. Evidence from randomized controlled trials indicates that treatment with natural surfactants results in faster weaning of supplemental oxygen and mean airway pressure, decreased duration of mechanical ventilation, and decreased mortality when compared to synthetic surfactants. Furthermore, at the present time, there are no approved synthetic surfactants available for use in preterm infants. Beractant, calfactant and poractant alpha are the three commonly used natural surfactants worldwide. Comparative studies including prospective randomized trials as well as large retrospective studies have shown significant differences in outcome and cost among these three natural surfactants. Of the eight prospective, randomized controlled trials and two retrospective studies involving the natural surfactant preparations, treatment with poractant alpha resulted in a significantly decreased mortality, decreased need for additional doses, faster weaning of oxygen and reduced hospital costs when compared to treatment with beractant or calfactant. These differences in outcome may be due to differences in phospholipid and SP-B content, amount of antioxidant phospholipids, plasmalogens, anti-inflammatory properties and viscosity among these three surfactants. Additional studies of administering surfactant non-invasively via laryngeal mask airway in preterm infants weighing >1,200 g and as an aerosol preparation are currently in progress.
呼吸窘迫综合征（RDS）是早产儿呼吸功能不全最常见的原因，尤其是孕周小于30周出生的婴儿。自20世纪70年代以来，持续气道正压通气一直作为RDS的主要治疗方式。表面活性剂疗法于20世纪80年代问世，已成为患有RDS或有RDS风险婴儿的标准治疗方法。表面活性剂疗法已被证明可减少气漏、新生儿和婴儿死亡率以及幸存者的费用。从动物来源获得的含有表面活性蛋白B（SP-B）和C（SP-C）的天然表面活性剂以及具有功能性SP-B或SP-C样蛋白模拟物的合成表面活性剂已在患有RDS或有RDS风险的早产儿中进行了广泛评估。随机对照试验的证据表明，与合成表面活性剂相比，使用天然表面活性剂治疗可使补充氧气和平均气道压力更快撤机，机械通气时间缩短，死亡率降低。此外，目前尚无获批用于早产儿的合成表面活性剂。贝拉克坦、卡肺表面活性剂和泊拉坦α是全球常用的三种天然表面活性剂。包括前瞻性随机试验以及大型回顾性研究在内的比较研究表明，这三种天然表面活性剂在疗效和成本方面存在显著差异。在八项涉及天然表面活性剂制剂的前瞻性随机对照试验和两项回顾性研究中，与使用贝拉克坦或卡肺表面活性剂治疗相比，使用泊拉坦α治疗可显著降低死亡率、减少额外剂量的需求、更快撤机并降低住院费用。这些疗效差异可能是由于这三种表面活性剂在磷脂和SP-B含量、抗氧化磷脂量、缩醛磷脂、抗炎特性和粘度方面存在差异。目前正在对体重>1200g的早产儿通过喉罩气道非侵入性给药表面活性剂以及作为气雾剂制剂进行更多研究。
