Farstad T, Bratlid D
Department of Pediatrics, Rikshospitalet, Oslo, Norway.
Biol Neonate. 1995;68(4):246-53. doi: 10.1159/000244242.
To understand the mechanisms behind the improved oxygenation after intratracheal surfactant instillation, the immediate effects of lung volume and pulmonary mechanics were analyzed. All infants studied were enrolled in multicenter trials in which surfactant therapy was instituted according to a rescue protocol. Infants received either synthetic surfactant (Exosurf) or modified porcine surfactant (Curosurf). Measurements of lung volume and pulmonary mechanics were successfully performed in 12 patients with a birth weight of 1.3 +/- (SD) 1.4 weeks. Functional residual capacity (FRC) and pulmonary mechanics were measured during mechanical ventilation. The FRC increased significantly by 70% (median), from 7.10 +/- (SD) 2.8 ml/kg to 11.5 +/- 3.3 ml/kg after surfactant instillation. However, a concomitant decrease in specific compliance was also seen. These findings could suggest that this immediate increase in FRC is initially nonuniform. However, since no significant correlation between changes in FRC and improvement in arterial-to-alveolar oxygen tension ratio is seen, other effects of surfactant must also be considered. These could include local and/or systemic changes in hemodynamics, such as decreased shunting as well as various effects on gas diffusion.
为了解气管内滴注表面活性剂后氧合改善背后的机制，分析了肺容积和肺力学的即时效应。所有研究的婴儿均参加了多中心试验，其中根据抢救方案实施表面活性剂治疗。婴儿接受合成表面活性剂（Exosurf）或改良猪表面活性剂（Curosurf）。对12例出生体重为1.3±（标准差）1.4周的患者成功进行了肺容积和肺力学测量。在机械通气期间测量功能残气量（FRC）和肺力学。表面活性剂滴注后，FRC显著增加70%（中位数），从7.10±（标准差）2.8 ml/kg增至11.5±3.3 ml/kg。然而，同时也观察到比顺应性下降。这些发现可能表明FRC的这种即时增加最初是不均匀的。然而，由于未观察到FRC变化与动脉-肺泡氧分压比改善之间存在显著相关性，因此还必须考虑表面活性剂的其他效应。这些效应可能包括血液动力学的局部和/或全身变化，如分流减少以及对气体扩散的各种影响。
