英国贝尔法斯特女王大学Daniel F. McAuley团队比较了体外二氧化碳清除促进的低潮气量通气与标准护理通气对急性低氧性呼吸衰竭患者90天死亡率的影响。2021年8月31日，《美国医学会杂志》发表了这一成果。

对于因急性低氧性呼吸衰竭需要机械通气的患者，与常规低潮气量通气相比，进一步减少潮气量可能会改善预后。

为了确定采用体外二氧化碳清除的低潮气量机械通气是否能改善急性低氧性呼吸衰竭患者的预后，研究组进行了一项多中心、随机、隐藏分配、开放标签、实用的临床试验，2016年5月至2019年12月，在英国51个重症监护病房纳入412名因急性低氧性呼吸衰竭接受机械通气的成年患者，计划样本量为1120例。后续随访于2020年3月11日结束。

将参与者随机分组，其中202例接受至少48小时的体外二氧化碳清除促进的低潮气量通气，210例接受常规低潮气量通气的标准护理。主要结局为随机分组后90天的全因死亡率。预先确定的次要结局包括第28天无呼吸机天数和不良事件发生率。

412名随机分组的患者平均年龄为59岁，143例（35%）为女性，405例（98%）完成了试验。根据数据监测和伦理委员会的建议，由于无效和可行性，试验提前终止。低潮气量体外二氧化碳清除通气组患者的90天死亡率为41.5%，标准护理组为39.5%，组间差异不显著。

与标准护理组相比，体外二氧化碳清除组的平均无呼吸机天数为7.1天，显著短于标准护理组的9.2天。体外二氧化碳清除组和标准护理组分别有62名患者（31%）和18名患者（9%）发生严重不良事件，其中体外二氧化碳清除组和对照组分别有9名患者（4.5%）和0名患者（0%）发生颅内出血，6名患者（3.0%）和1名患者（0.5%）发生其他部位出血。总体而言，21名患者经历了22起与研究装置相关的严重不良事件。

研究结果表明，对于急性低氧性呼吸衰竭患者，使用体外二氧化碳清除促进低潮气量机械通气，与常规低潮气量机械通气相比，没有显著降低90天死亡率。

附：英文原文

Title: Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal vs Standard Care Ventilation on 90-Day Mortality in Patients With Acute Hypoxemic Respiratory Failure: The REST Randomized Clinical Trial

Author: James J. McNamee, Michael A. Gillies, Nicholas A. Barrett, Gavin D. Perkins, William Tunnicliffe, Duncan Young, Andrew Bentley, David A. Harrison, Daniel Brodie, Andrew J. Boyle, Jonathan E. Millar, Tamas Szakmany, Jonathan Bannard-Smith, Redmond P. Tully, Ashley Agus, Clíona McDowell, Colette Jackson, Daniel F. McAuley, REST Investigators, Temi Adedoyin, Kayode Adeniji, Caroline Aherne, Gopal Anand Iyer, Prematie Andreou, Gillian Andrew, Ian Angus, Gill Arbane, Pauline Austin, Karen Austin, Georg Auzinger, Jonathan Ball, Dorota Banach, Jonathan Bannard-Smith, Leona Bannon, Lucy Barclay, Helena Barcraft-Barnes, Richard Beale, Sarah Bean, Andrew Bentley, Georgia Bercades, Colin Bergin, Sian Bhardwaj, Colin Bigham, Isobel Birkinshaw, Euan Black, Aneta Bociek, Andrew Bodenham, Malcolm G Booth, Christine Bowyer, David A Brealey, Stephen Brett, Jennifer Brooks, Karen Burt, Louise Cabrelli, Leilani Cabreros, Hazel Cahill, Aidan Campbell, Luigi Camporota, Sara Campos, Julie Camsooksai, Ronald Carrera, Joseph Carter, Jaime Carungcong, Anelise Catelan-Zborowski, Susanne Cathcart, Shreekant Champanerkar, Matthew Charlton, Shiney Cherian, Linsey Christie, Srikanth Chukkambotla, Amy Clark, Sarah Clark

Issue&Volume: 2021-08-31

Abstract:

Importance  In patients who require mechanical ventilation for acute hypoxemic respiratory failure, further reduction in tidal volumes, compared with conventional low tidal volume ventilation, may improve outcomes.

Objective  To determine whether lower tidal volume mechanical ventilation using extracorporeal carbon dioxide removal improves outcomes in patients with acute hypoxemic respiratory failure.

Design, Setting, and Participants  This multicenter, randomized, allocation-concealed, open-label, pragmatic clinical trial enrolled 412 adult patients receiving mechanical ventilation for acute hypoxemic respiratory failure, of a planned sample size of 1120, between May 2016 and December 2019 from 51 intensive care units in the UK. Follow-up ended on March 11, 2020.

Interventions  Participants were randomized to receive lower tidal volume ventilation facilitated by extracorporeal carbon dioxide removal for at least 48 hours (n=202) or standard care with conventional low tidal volume ventilation (n=210).

Main Outcomes and Measures  The primary outcome was all-cause mortality 90 days after randomization. Prespecified secondary outcomes included ventilator-free days at day 28 and adverse event rates.

Results  Among 412 patients who were randomized (mean age, 59 years; 143 [35%] women), 405 (98%) completed the trial. The trial was stopped early because of futility and feasibility following recommendations from the data monitoring and ethics committee. The 90-day mortality rate was 41.5% in the lower tidal volume ventilation with extracorporeal carbon dioxide removal group vs 39.5% in the standard care group (risk ratio, 1.05 [95% CI, 0.83-1.33]; difference, 2.0% [95% CI, 7.6% to 11.5%]; P=.68). There were significantly fewer mean ventilator-free days in the extracorporeal carbon dioxide removal group compared with the standard care group (7.1 [95% CI, 5.9-8.3] vs 9.2 [95% CI, 7.9-10.4] days; mean difference, 2.1 [95% CI, 3.8 to 0.3]; P=.02). Serious adverse events were reported for 62 patients (31%) in the extracorporeal carbon dioxide removal group and 18 (9%) in the standard care group, including intracranial hemorrhage in 9 patients (4.5%) vs 0 (0%) and bleeding at other sites in 6 (3.0%) vs 1 (0.5%) in the extracorporeal carbon dioxide removal group vs the control group. Overall, 21 patients experienced 22 serious adverse events related to the study device.

Conclusions and Relevance  Among patients with acute hypoxemic respiratory failure, the use of extracorporeal carbon dioxide removal to facilitate lower tidal volume mechanical ventilation, compared with conventional low tidal volume mechanical ventilation, did not significantly reduce 90-day mortality. However, due to early termination, the study may have been underpowered to detect a clinically important difference.

DOI: 10.1001/jama.2021.13374

Source: https://jamanetwork.com/journals/jama/fullarticle/2783809