Division of Nephrology, Kidney Research Institute, West China Hospital of Sichuan University, Chengdu, China.
State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, First Medical Center of Chinese, PLA General Hospital, Beijing, China.
Ann Med. 2023 Dec;55(1):746-759. doi: 10.1080/07853890.2023.2172606.
Acute respiratory failure (ARF) is a common clinical critical syndrome with substantial mortality. Extracorporeal carbon dioxide removal (ECCOR) has been proposed for the treatment of ARF. However, whether ECCOR could provide a survival advantage for patients with ARF is still controversial.
Electronic databases (PubMed, Embase, Web of Science, and the Cochrane database) were searched from inception to 30 April 2022. Randomized controlled trials (RCTs) and observational studies that examined the following outcomes were included: mortality, length of hospital and ICU stay, intubation and tracheotomy rate, mechanical ventilation days, ventilator-free days (VFDs), respiratory parameters, and reported adverse events.
Four RCTs and five observational studies including 1173 participants with ARF due to COPD or ARDS were included in this meta-analysis. Pooled analyses of related studies showed no significant difference in overall mortality between ECCOR and control group, neither in RCTs targeted ARDS or acute hypoxic respiratory failure patients (RR 1.05, 95% CI 0.83 to 1.32, = 0.70, I =0.0%), nor in studies targeted patients with ARF secondary to COPD (RR 0.80, 95% CI 0.58 to 1.11, = 0.19, I =0.0%). A shorter duration of ICU stay in the ECCOR group was only obtained in observational studies (WMD -4.25, < 0.01), and ECCOR was associated with a longer length of hospital stay ( = 0.02). ECCOR was associated with lower intubation rate ( < 0.01) and tracheotomy rate ( = 0.01), and shorter mechanical ventilation days ( < 0.01) in comparison to control group in ARF patients with COPD. In addition, an improvement in pH ( = 0.01), PaO2 ( = 0.01), respiratory rate ( < 0.01), and PaCO2 ( = 0.04) was also observed in patients with COPD exacerbations by ECCOR therapy. However, the ECCOR-related complication rate was high in six of the included studies.
Our findings from both RCTs and observational studies did not confirm a significant beneficial effect of ECCOR therapy on mortality. A shorter length of ICU stay in the ECCOR group was only obtained in observational studies, and ECCOR was associated with a longer length of hospital stay. ECCOR was associated with lower intubation rate and tracheotomy rate, and shorter mechanical ventilation days in ARF patients with COPD. And an improvement in pH, PaO2, respiratory rate and PaCO2 was observed in the ECCOR group. However, outcomes largely relied on data from observational studies targeted patients with ARF secondary to COPD, thus further larger high-quality RCTs are desirable to strengthen the evidence on the efficacy and benefits of ECCOR for patients with ARF.Key messagesECCOR therapy did not confirm a significant beneficial effect on mortality.ECCOR was associated with lower intubation and tracheotomy rate, and shorter mechanical ventilation days in patients with ARF secondary to COPD.An improvement in pH, PaO2, respiratory rate, and PaCO2 was observed in ECCOR group in patients with COPD exacerbations.Evidence for the future application of ECCOR therapy for patients with ARF. The protocol of this meta-analysis was registered on PROSPERO (CRD42022295174).
急性呼吸衰竭（ARF）是一种常见的临床危急综合征，死亡率较高。体外二氧化碳去除（ECCOR）已被提议用于治疗 ARF。然而，ECCOR 是否能为 ARF 患者提供生存优势仍存在争议。
从成立到 2022 年 4 月 30 日，检索电子数据库（PubMed、Embase、Web of Science 和 Cochrane 数据库）。纳入的随机对照试验（RCT）和观察性研究评估了以下结局：死亡率、住院和 ICU 住院时间、插管和气管切开率、机械通气天数、无呼吸机天数（VFDs）、呼吸参数和报告的不良事件。
本 meta 分析纳入了 4 项 RCT 和 5 项观察性研究，共纳入 1173 例因 COPD 或 ARDS 导致 ARF 的患者。对相关研究的汇总分析显示，ECCOR 组与对照组在总体死亡率方面无显著差异，无论是在针对 ARDS 或急性低氧性呼吸衰竭患者的 RCT 中（RR 1.05，95%CI 0.83 至 1.32， = 0.70，I =0.0%），还是在针对 COPD 继发 ARF 的研究中（RR 0.80，95%CI 0.58 至 1.11， = 0.19，I =0.0%）。仅在观察性研究中观察到 ECCOR 组 ICU 住院时间更短（WMD-4.25， < 0.01），ECCOR 与住院时间更长相关（ = 0.02）。ECCOR 与 COPD 继发 ARF 患者的插管率（ < 0.01）和气管切开率（ = 0.01）较低，机械通气天数较短（ < 0.01）相关。此外，ECCOR 治疗还可改善 COPD 加重患者的 pH 值（ = 0.01）、PaO2（ = 0.01）、呼吸频率（ < 0.01）和 PaCO2（ = 0.04）。然而，纳入的 6 项研究中 ECCOR 相关并发症发生率较高。
我们从 RCT 和观察性研究中得出的发现并未证实 ECCOR 治疗对死亡率有显著的有益影响。仅在观察性研究中观察到 ECCOR 组 ICU 住院时间更短，ECCOR 与住院时间更长相关。ECCOR 与 COPD 继发 ARF 患者的插管率和气管切开率较低，机械通气天数较短。ECCOR 组患者的 pH 值、PaO2、呼吸频率和 PaCO2 得到改善。然而，结果主要依赖于针对 COPD 继发 ARF 患者的观察性研究数据，因此需要进一步进行更大规模、高质量的 RCT 以加强 ECCOR 治疗 ARF 患者的疗效和益处的证据。
ECCOR 治疗对死亡率无显著有益影响。ECCOR 与 COPD 继发 ARF 患者的插管和气管切开率较低，机械通气时间较短。ECCOR 组 COPD 加重患者的 pH 值、PaO2、呼吸频率和 PaCO2 得到改善。ECCOR 治疗 ARF 患者的未来应用证据。本 meta 分析的方案已在 PROSPERO（CRD42022295174）上注册。
