Department of Anesthesiology and Critical Care Medicine, Dalhousie University, Halifax, Canada.
PLoS One. 2012;7(8):e40190. doi: 10.1371/journal.pone.0040190. Epub 2012 Aug 16.
The efficacy of partial ventilatory support modes that allow spontaneous breathing in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is unclear. The objective of this scoping review was to assess the effects of partial ventilatory support on mortality, duration of mechanical ventilation, and both hospital and intensive care unit (ICU) lengths of stay (LOS) for patients with ALI and ARDS; the secondary objective was to describe physiologic effects on hemodynamics, respiratory system and other organ function.
MEDLINE (1966-2009), Cochrane, and EmBase (1980-2009) databases were searched using common ventilator modes as keywords and reference lists from retrieved manuscripts hand searched for additional studies. Two researchers independently reviewed and graded the studies using a modified Oxford Centre for Evidence-Based Medicine grading system. Studies in adult ALI/ARDS patients were included for primary objectives and pre-clinical studies for supporting evidence.
Two randomized controlled trials (RCTs) were identified, in addition to six prospective cohort studies, one retrospective cohort study, one case control study, 41 clinical physiologic studies and 28 pre-clinical studies. No study was powered to assess mortality, one RCT showed shorter ICU length of stay, and the other demonstrated more ventilator free days. Beneficial effects of preserved spontaneous breathing were mainly physiological effects demonstrated as improvement of gas exchange, hemodynamics and non-pulmonary organ perfusion and function.
The use of partial ventilatory support modalities is often feasible in patients with ALI/ARDS, and may be associated with short-term physiological benefits without appreciable impact on clinically important outcomes.
允许急性肺损伤（ALI）和急性呼吸窘迫综合征（ARDS）患者自主呼吸的部分通气支持模式的疗效尚不清楚。本范围综述的目的是评估部分通气支持对 ALI 和 ARDS 患者死亡率、机械通气时间以及住院和重症监护病房（ICU）住院时间（LOS）的影响；次要目的是描述对血流动力学、呼吸系统和其他器官功能的生理影响。
使用常见的通气模式作为关键字，检索 MEDLINE（1966-2009 年）、Cochrane 和 EmBase（1980-2009 年）数据库，并通过检索到的手稿的参考文献列表进行手工搜索以获取其他研究。两名研究人员使用改良的牛津循证医学中心评分系统独立审查和分级研究。将成人 ALI/ARDS 患者的研究纳入主要目标，将临床前研究纳入支持证据。
确定了两项随机对照试验（RCT），此外还有六项前瞻性队列研究、一项回顾性队列研究、一项病例对照研究、41 项临床生理学研究和 28 项临床前研究。没有一项研究有能力评估死亡率，一项 RCT 表明 ICU 住院时间缩短，另一项则表明有更多的无呼吸机天数。保留自主呼吸的有益作用主要是生理作用，表现为改善气体交换、血流动力学和非肺器官灌注和功能。
在 ALI/ARDS 患者中，部分通气支持模式的应用通常是可行的，并且可能与短期生理益处相关，而对临床重要结局没有明显影响。
