Extracorporeal membrane oxygenation shows benefit for patients with COVID-19 related severe acute respiratory distress syndrome.

1. Extracorporeal membrane oxygenation (ECMO) for COVID-19 related acute respiratory distress syndrome (ARDS) was associated with 60-day survival rates similar to other studies evaluating ECMO in severe ARDS.

2. ECMO in COVID-19 related ARDS was associated with an increased risk of pulmonary emboli despite thromboprophylaxis.

Evidence Rating Level: 2 (Good)

Study Rundown: There are over 17 million confirmed cases of COVID-19 internationally. Severe and critical COVID-19 may be associated with acute respiratory distress syndrome (ARDS) and severe hypoxemia. Previous case series from China found that COVID-19 related ARDS responded poorly to extracorporeal membrane oxygenation (ECMO), despite recommendations for its use worldwide during the pandemic. This multi-centre retrospective cohort study attempted to further characterize the use of ECMO in patients with severe COVID-19 ARDS. Patients receiving ECMO for COVID-19 related ARDS were included, and clinical status (and time spent in different clinical states) up to day 90 post-ECMO was the primary outcome of interest. Overall, patients on ECMO showed similar 60-day survival as previous studies of patients with non-COVID-19 related severe ARDS. Prone positioning prior to ECMO was associated with significant benefit. Despite thromboprophylaxis, there was an increased risk of pulmonary emboli in this population, consistent with previous reports of SARS-CoV-2 with associated lung endothelial injury. This study supports consideration of ECMO in the early management of patients with profound respiratory failure refractory to optimized conventional care including prone positioning. Limitations include only enrolling patients from sites highly experienced with ECMO use, limiting generalizability to less experienced and resource-limited sites.

Click to read the study in Lancet Respiratory Medicine

Click to read an accompanying editorial in Lancet Respiratory Medicine

Relevant reading: Poor survival with extracorporeal membrane oxygenation in acute respiratory distress syndrome (ARDS) due to coronavirus disease 2019 (COVID-19)

In-Depth [retrospective cohort]: This multi-center retrospective cohort study occurred in five hospitals across Paris, France, and enrolled 83 patients (median age 49, interquartile range [IQR]  41 to 56 years); 61 (73%) were men. Patients with laboratory-confirmed SARS-CoV-2 infection who received venoarterial or venovenous-ECMO for severe acute respiratory distress syndrome (ARDS) were included. ECMO was contraindicated if patients were over 70 years old or had other severe comorbidities, recent cardiac arrests, or invasive ventilation for longer than 10 days. The primary outcome was clinical status in one of four states: (i) on ECMO; (ii) in the intensive care unit (ICU) and weaned off ECMO; (iii) alive and out of ICU; and (iv) death. Clinical outcomes were assessed at several timepoints after beginning ECMO, up to day 90 post-ECMO initiation. Secondary outcomes involved characterizing complications related to ICU stay or ECMO. Among the 83 patients for whom ECMO was initiated, 67 (81%) were prone positioned, 80 (96%) received neuromuscular blockers, 17 (20%) received high-dose corticosteroids, and five (6%) received nitric oxide. ECMO support was provided for a median duration of 20 days (IQR 10 to 40), and median ICU length of stay was 36 days (IQR 23 to 60). Complete follow-up was available at 60 days for all 83 patients. The estimated likelihood of being in each of the four states at 60 days post-ECMO initiation were calculated as follows: (i) 6% (95% confidence interval [CI] 3 to 14%); (ii) 18% (95% CI 11 to 28%); (iii) 45% (95% CI 35 to 56%); and (iv) 31% (95% CI 22 to 42%). Amongst patients who were prone positioned, 94% showed benefit. Despite appropriate thromboprophylaxis, 16 (19%) patients developed a pulmonary embolism, which was higher than observed in patients with non-COVID-19 related ARDS on ECMO. 35 (42%) patients experienced major bleeding, with 4 (5%) experiencing hemorrhagic strokes. There were 30 deaths observed in follow-up.  Overall, given similar rates of survival to patients with non-COVID-19 ARDS on ECMO from previous studies, the use of ECMO in COVID-19 ARDS should be considered as a treatment modality for patients refractory to conventional optimization including prone positioning.

Image: PD

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