Hillman Noah H, Kemp Matthew W, Miura Yuichiro, Kallapur Suhas G, Jobe Alan H
Division of Neonatology, Cardinal Glennon Children's Medical Center, Saint Louis University, Saint Louis, Missouri, United States of America.
School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia.
PLoS One. 2014 Nov 24;9(11):e113473. doi: 10.1371/journal.pone.0113473. eCollection 2014.
Sustained inflations (SI) are used with the initiation of ventilation at birth to rapidly recruit functional residual capacity and may decrease lung injury and the need for mechanical ventilation in preterm infants. However, a 20 second SI in surfactant-deficient preterm lambs caused an acute phase injury response without decreasing lung injury from subsequent mechanical ventilation.
A 20 second SI at birth will decrease lung injury from mechanical ventilation in surfactant-treated preterm fetal lambs.
The head and chest of fetal sheep at 126±1 day GA were exteriorized, with tracheostomy and removal of fetal lung fluid prior to treatment with surfactant (300 mg in 15 ml saline). Fetal lambs were randomized to one of four 15 minute interventions: 1) PEEP 8 cmH2O; 2) 20 sec SI at 40 cmH2O, then PEEP 8 cmH2O; 3) mechanical ventilation with 7 ml/kg tidal volume; or 4) 20 sec SI then mechanical ventilation at 7 ml/kg. Fetal lambs remained on placental support for the intervention and for 30 min after the intervention.
SI recruited a mean volume of 6.8±0.8 mL/kg. SI did not alter respiratory physiology during mechanical ventilation. Heat shock protein (HSP) 70, HSP60, and total protein in lung fluid similarly increased in both ventilation groups. Modest pro-inflammatory cytokine and acute phase responses, with or without SI, were similar with ventilation. SI alone did not increase markers of injury.
In surfactant treated fetal lambs, a 20 sec SI did not alter ventilation physiology or markers of lung injury from mechanical ventilation.
出生时启动通气时使用持续充气（SI）来快速恢复功能残气量，并可能减少早产儿的肺损伤和机械通气需求。然而，在表面活性物质缺乏的早产羔羊中进行20秒的SI会引发急性期损伤反应，且并未减少随后机械通气所致的肺损伤。
出生时进行20秒的SI可减少表面活性物质治疗的早产胎羊机械通气所致的肺损伤。
将妊娠126±1天的胎羊头部和胸部露出，在气管切开并清除胎肺液体后给予表面活性物质（300mg溶于15ml盐水中）治疗。胎羊被随机分为四个15分钟干预组之一：1）呼气末正压（PEEP）8cmH₂O；2）40cmH₂O下20秒SI，然后PEEP 8cmH₂O；3）潮气量7ml/kg的机械通气；或4）20秒SI然后潮气量7ml/kg的机械通气。胎羊在干预期间及干预后30分钟内维持胎盘支持。
SI使平均肺容量增加6.8±0.8mL/kg。SI在机械通气期间未改变呼吸生理。两个通气组肺液中的热休克蛋白（HSP）70、HSP60和总蛋白同样增加。无论有无SI，适度的促炎细胞因子和急性期反应在通气时相似。单独的SI未增加损伤标志物。
在表面活性物质治疗的胎羊中，20秒的SI未改变机械通气的通气生理或肺损伤标志物。
