Pellegrini José Augusto S, Moraes Rafael B, Maccari Juçara G, de Oliveira Roselaine P, Savi Augusto, Ribeiro Rodrigo A, Burns Karen Ea, Teixeira Cassiano
Division of Critical Care, Hospital Moinhos de Vento (HMV), Porto Alegre, RS, Brazil.
Division of Critical Care, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil.
Respir Care. 2016 Dec;61(12):1693-1703. doi: 10.4187/respcare.04816. Epub 2016 Sep 6.
Spontaneous breathing trials (SBTs) are among the most commonly employed techniques to facilitate weaning from mechanical ventilation. The preferred SBT technique, however, is still unclear. To clarify the preferable SBT (T-piece or pressure support ventilation [PSV]), we conducted this systematic review. We then searched the MEDLINE, EMBASE, SciELO, Google Scholar, CINAHL, ClinicalTrials.gov, and Cochrane CENTRAL databases through June 2015, without language restrictions. We included randomized controlled trials involving adult subjects being weaned from mechanical ventilation comparing T-piece with PSV and reporting (1) weaning failure, (2) re-intubation rate, (3) ICU mortality, or (4) weaning duration. Anticipating clinical heterogeneity among the included studies, we compared prespecified subgroups: (1) simple, difficult, or prolonged weaning and (2) subjects with COPD. We summarized the quality of evidence for intervention effects using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) methodology. We identified 3,674 potentially relevant studies and reviewed 23 papers in full. Twelve studies (2,161 subjects) met our inclusion criteria. Overall, the evidence was of very low to low quality. SBT technique did not influence weaning success (risk ratio 1.23 [0.94-1.61]), ICU mortality (risk ratio 1.11 [0.80-1.54]), or re-intubation rate (risk ratio 1.21 [0.90-1.63]). Prespecified subgroup analysis suggested that PSV might be superior to T-piece with regard to weaning success for simple-to-wean subjects (risk ratio 1.44 [1.11-1.86]). For the prolonged-weaning subgroup, however, T-piece was associated with a shorter weaning duration (weighted mean difference -3.08 [-5.24 to -0.92] d). In conclusion, low-quality evidence is available concerning this topic. PSV may be associated with lower weaning failure rates in the simple-to-wean subgroup. In contrast, in prolonged-weaning subjects, T-piece may be related to a shorter weaning duration, although this is at high risk of bias. Further study of the difficult-to-wean and COPD subgroups is required.
自主呼吸试验（SBTs）是促进机械通气撤机最常用的技术之一。然而，首选的SBT技术仍不明确。为了明确更优的SBT（T管或压力支持通气[PSV]），我们进行了这项系统评价。我们检索了截至2015年6月的MEDLINE、EMBASE、SciELO、谷歌学术、CINAHL、ClinicalTrials.gov和Cochrane CENTRAL数据库，无语言限制。我们纳入了涉及从机械通气撤机的成年受试者的随机对照试验，比较T管与PSV，并报告（1）撤机失败、（2）再次插管率、（3）ICU死亡率或（4）撤机持续时间。预期纳入研究之间存在临床异质性，我们比较了预先设定的亚组：（1）简单、困难或延长撤机以及（2）慢性阻塞性肺疾病（COPD）患者。我们使用GRADE（推荐分级评估、制定和评价）方法总结了干预效果的证据质量。我们识别出3674项潜在相关研究，并对23篇论文进行了全文审查。12项研究（2161名受试者）符合我们的纳入标准。总体而言，证据质量极低至低。SBT技术不影响撤机成功率（风险比1.23[0.94 - 1.61]）、ICU死亡率（风险比1.11[0.80 - 1.54]）或再次插管率（风险比1.21[0.90 - 1.63]）。预先设定的亚组分析表明，对于易于撤机的受试者，在撤机成功率方面PSV可能优于T管（风险比1.44[1.11 - 1.86]）。然而，对于延长撤机亚组，T管与较短的撤机持续时间相关（加权平均差 - 3.08[-5.24至 - 0.92]天）。总之，关于这个主题的证据质量较低。在易于撤机的亚组中，PSV可能与较低的撤机失败率相关。相比之下，在延长撤机的受试者中，T管可能与较短的撤机持续时间相关，尽管这存在较高的偏倚风险。需要对难以撤机和COPD亚组进行进一步研究。
