Pressure-limited sustained inflation vs. gradual tidal inflations for resuscitation in preterm lambs.
Pressure-limited sustained inflation vs. gradual tidal inflations for resuscitation in preterm lambs.
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压力限制的持续通货膨胀与渐进的潮汐通货膨胀对早产羔羊的复苏。
DOI：
10.1152/japplphysiol.00985.2014
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Pillow,JJane
中科院分区：
文献类型：
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作者：
Tingay,DavidG;Polglase,GraemeR;Bhatia,Risha;Berry,ClareA;Kopotic,RobertJ;Kopotic,ClintonP;Song,Yong;Szyld,Edgardo;Jobe,AlanH;Pillow,JJane
支持机械复杂的早产儿肺需要促进通气，同时避免通气异质性：是否逐渐或快速实现这一点仍不清楚。我们比较了渐进式与恒定潮气量充气和出生时压力限制性持续充气（SI）对妊娠131天早产羔羊的气体交换、肺力学、重力依赖性肺容积分布和肺损伤的影响。从出生开始，采用1）20-s，40-cmH 2 O压力限制SI（PressSI），2）潮气量（Vt）在5-min内从3 ml/kg逐渐增加到7 ml/kg（IncrVt）或3）7 ml/kg Vt复苏羔羊。所有羔羊随后以7 ml/kg Vt通气15 min，呼气末压相同。定期记录肺力学、气体交换和呼气末容积（EEV）的空间分布以及潮气通气（电阻抗断层扫描）。在15分钟时，评估肺损伤的早期mRNA组织标志物。IncrVt组在5 min时的组织阻力更大（P= 0.017;双因素方差分析），10 min时的肺泡-动脉氧差更高（P< 0.01），EEV的重力依赖性分布最不均匀。各组之间的肺力学没有其他差异，PressSI和7 ml/kg Vt组的表现始终相似。在PressSI组中，EEV分布更均匀，但至少如此。肺损伤的mRNA标志物无差异。从出生开始逐渐增加的Vt导致重力依赖性肺的募集减少，氧合变差。出生时SI与使用7 ml/kg Vt的机械通气相比没有任何益处。
Support of the mechanically complex preterm lung needs to facilitate aeration while avoiding ventilation heterogeneities: whether to achieve this gradually or quickly remains unclear. We compared the effect of gradual vs. constant tidal inflations and a pressure-limited sustained inflation (SI) at birth on gas exchange, lung mechanics, gravity-dependent lung volume distribution, and lung injury in 131-day gestation preterm lambs. Lambs were resuscitated with either1) a 20-s, 40-cmH2O pressure-limited SI (PressSI),2) a gradual increase in tidal volume (Vt) over 5-min from 3 ml/kg to 7 ml/kg (IncrVt), or3) 7 ml/kg Vtfrom birth. All lambs were subsequently ventilated for 15 min with 7 ml/kg Vtwith the same end-expiratory pressure. Lung mechanics, gas exchange and spatial distribution of end-expiratory volume (EEV), and tidal ventilation (electrical impedance tomography) were recorded regularly. At 15 min, early mRNA tissue markers of lung injury were assessed. The IncrVtgroup resulted in greater tissue hysteresivity at 5 min (P= 0.017; two-way ANOVA), higher alveolar-arterial oxygen difference from 10 min (P< 0.01), and least uniform gravity-dependent distribution of EEV. There were no other differences in lung mechanics between groups, and the PressSI and 7 ml/kg Vtgroups behaved similarly throughout. EEV was more uniformly distributed, but Vtleast so, in the PressSI group. There were no differences in mRNA markers of lung injury. A gradual increase in Vtfrom birth resulted in less recruitment of the gravity-dependent lung with worse oxygenation. There was no benefit of a SI at birth over mechanical ventilation with 7 ml/kg Vt.