Is Extracorporeal Membrane Oxygenation the Standard Care for Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

Abstract

Background Acute respiratory distress syndrome (ARDS) is a type of acute respiratory failure syndrome characterised by severe respiratory distress and stubborn hypoxaemia. Patients with ARDS have a prolonged hospital stay and high mortality rate. Over long-term follow-up, ARDS is found to be associated with a high incidence of long-term complications and decreased quality of life. Venovenous extracorporeal membrane oxygenation (vv-ECMO) has been widely used for the treatment of refractory ARDS. However, it is not the standard treatment as recommended by ARDS guidelines. Aim The aim of this study was to compare the effects of ECMO (vv-ECMO) and conventional mechanical ventilation (CMV) on the clinical outcomes in patients with ARDS. Method We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, Medline, EMBASE, Web of Science, and PubMed databases up to November 2019. We selected appropriate studies according to our inclusion and exclusion criteria, and extracted and analysed the data using RevMan 5.0 software to evaluate the effectiveness of ECMO systematically. Results A total of 18 articles and 2,399 patients were included in this meta-analysis: 898 patients in the ECMO group and 1,501 patients in the CMV group. Treatment with ECMO may be associated with reduced 1-year mortality (95% confidence interval [CI], 0.27–0.83; p=0.009) and 60-day mortality (95% CI, 0.37–0.86; p=0.008), but increased Intensive Care Unit mortality (95% CI, 1.26–2.36; p=0.0007) of patients with ARDS. Extracorporeal membrane oxygenation may not be related to 30-day mortality or complications such as nosocomial pneumonia, haemorrhagic stroke, or continuous renal replacement therapy in patients with ARDS. However, some results showed heterogeneity, such as bleeding complications and in-hospital mortality. Subgroup analysis showed that ECMO treatment might increase ICU mortality (p=0.002) and nosocomial pneumonia complications (p=0.03) in patients with H1N1 ARDS. Conclusions Compared with CMV, ECMO contributed to lower 60-day and 1-year mortality, and increased ICU mortality in patients with ARDS. However, H1N1 ARDS was independently associated with higher ICU mortality and nosocomial pneumonia. The results were not affected by removing retrospective control studies or articles published >20 years ago from the sensitivity analysis. This meta-analysis demonstrates the effectiveness of ECMO and its importance in standard treatment of patients with ARDS.

Extracorporeal Membrane Oxygenation in Acute Respiratory Distress Syndrome: How Do We Expand Capacity in the COVID-19 Era?

“…Despite advances in medical technology, the mortality rate for severe acute respiratory distress syndrome (ARDS) remains high at around 40% [1]. In recent years, multiple studies, systematic reviews, and meta-analyses [2][3][4][5], including the study in this issue of Heart, Lung and Circulation published by Wang and colleagues [4], have indicated that treatment with veno-venous extracorporeal membrane oxygenation (VV-ECMO) may be associated with better outcomes in severe ARDS than conventional mechanical ventilation. Increasing evidence will likely lead to an increase in the use of VV-ECMO in the treatment of ARDS in the coming years [6].…”

“…ARDS is an acute inflammatory lung injury resulting in widespread alveolar injury and hypoxaemia [4,7]. There is no gold standard to diagnose ARDS, and each ARDS case can have a multitude of causes [7].…”

“…Many providers diagnose ARDS based on the Berlin criteria which take into account the timing of symptoms, chest imaging, the presence of other possible explanations for pulmonary oedema, and oxygenation requirements [8]. In their article, Wang and colleagues perform a comprehensive literature review and metaanalysis of research examining the utility of ECMO in the treatment of ARDS [4]. They found that ECMO treatment was associated with improved 60-day and 1-year mortality but increased intensive care unit (ICU) mortality [4].…”

“…In their article, Wang and colleagues perform a comprehensive literature review and metaanalysis of research examining the utility of ECMO in the treatment of ARDS [4]. They found that ECMO treatment was associated with improved 60-day and 1-year mortality but increased intensive care unit (ICU) mortality [4]. Applying these findings within the complex ecosystem of the ICU requires a consideration of patient, provider, and systems-level issues.…”

“…In the United States, adult respiratory ECMO "runs" increased from 92 cases in 2008 to 3,133 in 2019, and the survival rate has increased from 39% to 65% within the same time period [12]. In the coming years, results like those published by Wang and colleagues will continue to encourage clinicians to consider ECMO therapy for their patients with severe ARDS, particularly in the post COVID era [4]. The increasing use of ECMO for respiratory failure and ARDS treatment raises questions about how to increase capacity to safely and effectively deliver ECMO.…”