Spontaneous Airway Pressure Release Ventilation (s-aprv)

1. 我们复制了绵羊呼吸机相关的医院性肺炎（VAP）的高发病率，这些羊的护理与目前在医院ICU中使用机械通气的患者的护理相似：头部抬高半卧位，定期气管吸引。健康羊麻醉麻痹后，俯卧位机械肺通气，将头、颈、气管管抬高30度以上，定期吸痰。绵羊出现进行性气体交换障碍、败血症，有时甚至死亡。气管和支气管肺树均匀地大量定植病原体。早期的研究，使用持续声门下抽吸（Hi-Lo evac Mallinckrodt ETT），并没有改变这种不良的结果。然而，当羊俯卧72h，气管/气管管水平放置，不吸痰（常规或非常规）时，气管和肺给叶中没有病原体生长（在11个部位取样），肺功能保持正常，肺表现正常。我们还表明，气管管可以水平定向与我们的定制龙门架系统，定期旋转羊从一边到另一边，同样良好的结果。重要的是，鼻胃喂养具有良好的耐受性（与传统做法相反）。我们相信，基于我们的研究，这种龙门式系统和常规护理很容易适应临床使用。2. 我们开发了一种薄壁/两级/最低死亡空间/最低阻力/双气管内管（UTTS-T-ETT），用于成人、儿童或婴儿。在早产儿中，该系统的死亡空间低于健康的非插管新生儿。这样的系统可以使患者以最少的努力进行CPAP，并且可能大大减少所有年龄组患者对机械通气的需求。

1. We have replicated high incidence of ventilator associated nosocomial pneumonia (VAP) in sheep, subjected to care similar to that now practiced in patients on mechanical ventilation in a hospital ICU: semirecumbent position with head elevated 30 , and periodic tracheal suctioning. Healthy sheep, anesthetized and paralyzed, were subjected to mechanical pulmonary ventilation in the prone position, with head, neck, and tracheal tube elevated 30 above horizontal, and suctioned periodically. Sheep developed progressive impairment of gas exchange, sepsis, and sometimes death. The trachea and the bronchopulmonary tree were uniformly heavily colonized with pathogens. Early studies, using continuous subglottic suctioning (Hi-Lo evac Mallinckrodt ETT), did not change this poor outcome. However, when sheep were positioned for 72 h prone, with trachea/tracheal tube horizontal and with no suctioning (routinely or otherwise), there was no growth of pathogens in the trachea and the give lobes of the lungs (sampled at 11 sites), normal lung function remained, and lungs appeared normal. We have also shown that the tracheal tube can be oriented horizontally with our custom gantry system, with periodic rotation of sheep from side to side, with equally good results. Importantly, nasogastric feeding was well tolerated (in contrast to conventional practice). We believe this gantry system and routine care based on our studies is readily adaptable to clinical use. 2. We have developed a thin-walled/two stage/lowest dead space/lowest resistance/twin endotracheal tube (UTTS-T-ETT) for use in adult, child, or infant. In the preterm infant, the dead space of this system is lower than that in the healthy, non-intubated newborn. Such a system can permit CPAP with least patient effort, and is likely to reduce greatly the need for mechanical ventilation in patients of all age groups.