Rose Louise, Schultz Marcus J, Cardwell Chris R, Jouvet Philippe, McAuley Danny F, Blackwood Bronagh
Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, 155 College St, Toronto, ON, Canada, M5T 1P8.
Cochrane Database Syst Rev. 2014 Jun 10;2014(6):CD009235. doi: 10.1002/14651858.CD009235.pub3.
Automated closed loop systems may improve adaptation of mechanical support for a patient's ventilatory needs and facilitate systematic and early recognition of their ability to breathe spontaneously and the potential for discontinuation of ventilation. This review was originally published in 2013 with an update published in 2014.
The primary objective for this review was to compare the total duration of weaning from mechanical ventilation, defined as the time from study randomization to successful extubation (as defined by study authors), for critically ill ventilated patients managed with an automated weaning system versus no automated weaning system (usual care).Secondary objectives for this review were to determine differences in the duration of ventilation, intensive care unit (ICU) and hospital lengths of stay (LOS), mortality, and adverse events related to early or delayed extubation with the use of automated weaning systems compared to weaning in the absence of an automated weaning system.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 8); MEDLINE (OvidSP) (1948 to September 2013); EMBASE (OvidSP) (1980 to September 2013); CINAHL (EBSCOhost) (1982 to September 2013); and the Latin American and Caribbean Health Sciences Literature (LILACS). Relevant published reviews were sought using the Database of Abstracts of Reviews of Effects (DARE) and the Health Technology Assessment Database (HTA Database). We also searched the Web of Science Proceedings; conference proceedings; trial registration websites; and reference lists of relevant articles. The original search was run in August 2011, with database auto-alerts up to August 2012.
We included randomized controlled trials comparing automated closed loop ventilator applications to non-automated weaning strategies including non-protocolized usual care and protocolized weaning in patients over four weeks of age receiving invasive mechanical ventilation in an ICU.
Two authors independently extracted study data and assessed risk of bias. We combined data in forest plots using random-effects modelling. Subgroup and sensitivity analyses were conducted according to a priori criteria.
We included 21 trials (19 adult, two paediatric) totaling 1676 participants (1628 adults, 48 children) in this updated review. Pooled data from 16 eligible trials reporting weaning duration indicated that automated closed loop systems reduced the geometric mean duration of weaning by 30% (95% confidence interval (CI) 13% to 45%), however heterogeneity was substantial (I(2) = 87%, P < 0.00001). Reduced weaning duration was found with mixed or medical ICU populations (42%, 95% CI 10% to 63%) and Smartcare/PS™ (28%, 95% CI 7% to 49%) but not in surgical populations or using other systems. Automated closed loop systems reduced the duration of ventilation (10%, 95% CI 3% to 16%) and ICU LOS (8%, 95% CI 0% to 15%). There was no strong evidence of an effect on mortality rates, hospital LOS, reintubation rates, self-extubation and use of non-invasive ventilation following extubation. Prolonged mechanical ventilation > 21 days and tracheostomy were reduced in favour of automated systems (relative risk (RR) 0.51, 95% CI 0.27 to 0.95 and RR 0.67, 95% CI 0.50 to 0.90 respectively). Overall the quality of the evidence was high with the majority of trials rated as low risk.
AUTHORS' CONCLUSIONS: Automated closed loop systems may result in reduced duration of weaning, ventilation and ICU stay. Reductions are more likely to occur in mixed or medical ICU populations. Due to the lack of, or limited, evidence on automated systems other than Smartcare/PS™ and Adaptive Support Ventilation no conclusions can be drawn regarding their influence on these outcomes. Due to substantial heterogeneity in trials there is a need for an adequately powered, high quality, multi-centre randomized controlled trial in adults that excludes 'simple to wean' patients. There is a pressing need for further technological development and research in the paediatric population.
自动闭环系统可改善对患者通气需求的机械支持适配性，并有助于系统且早期地识别患者自主呼吸能力及通气中断的可能性。本综述最初发表于2013年，并于2014年进行了更新。
本综述的主要目的是比较使用自动撤机系统与不使用自动撤机系统（常规护理）的重症通气患者从机械通气撤机的总时长，撤机总时长定义为从研究随机分组至成功拔管（由研究作者定义）的时间。本综述的次要目的是确定与未使用自动撤机系统的撤机相比，使用自动撤机系统在通气时长、重症监护病房（ICU）和医院住院时长、死亡率以及与早期或延迟拔管相关的不良事件方面的差异。
我们检索了Cochrane对照试验中心注册库（CENTRAL）（《Cochrane图书馆》2013年第8期）；MEDLINE（OvidSP）（1948年至2013年9月）；EMBASE（OvidSP）（1980年至2013年9月）；护理学与健康照护领域数据库（CINAHL）（EBSCOhost）（1982年至2013年9月）；以及拉丁美洲和加勒比健康科学文献数据库（LILACS）。使用效果综述摘要数据库（DARE）和卫生技术评估数据库（HTA数据库）查找相关已发表综述。我们还检索了科学网会议录；会议论文集；试验注册网站；以及相关文章的参考文献列表。最初的检索于2011年8月进行，并设置了截至2012年8月的数据库自动提醒。
我们纳入了比较自动闭环通气应用与非自动撤机策略的随机对照试验，非自动撤机策略包括在ICU接受有创机械通气超过四周的患者的非标准化常规护理和标准化撤机。
两位作者独立提取研究数据并评估偏倚风险。我们使用随机效应模型在森林图中合并数据。根据预先设定的标准进行亚组分析和敏感性分析。
在本次更新综述中，我们纳入了21项试验（19项成人试验，2项儿科试验），共计1676名参与者（1628名成人，48名儿童）。16项报告撤机时长的合格试验的汇总数据表明，自动闭环系统使撤机的几何平均时长缩短了30%（95%置信区间（CI）为13%至45%），然而异质性很大（I² = 87%，P < 0.00001）。在混合或内科ICU人群（42%，95% CI为10%至63%）以及Smartcare/PS™系统（28%，95% CI为7%至49%）中发现撤机时长缩短，但在外科人群或使用其他系统时未发现。自动闭环系统缩短了通气时长（10%，95% CI为3%至16%）和ICU住院时长（8%，95% CI为0%至15%）。没有有力证据表明对死亡率、医院住院时长、再次插管率、自行拔管以及拔管后无创通气的使用有影响。支持自动系统的是，机械通气时间延长>21天和气管切开术减少（相对风险（RR）分别为0.51，95% CI为0.27至0.95和RR为0.67，95% CI为0.50至0.90）。总体而言，证据质量较高，大多数试验被评为低风险。
自动闭环系统可能会缩短撤机、通气和ICU住院时长。在混合或内科ICU人群中更有可能出现时长缩短。由于除Smartcare/PS™和适应性支持通气外，关于自动系统的证据不足或有限，无法就它们对这些结果的影响得出结论。由于试验存在大量异质性，需要在成人中进行一项样本量充足、高质量的多中心随机对照试验，排除“易于撤机”的患者。儿科人群迫切需要进一步的技术开发和研究。
