Lessons Learned From Awake ECMO Approach in Covid-19-Related Acute Respiratory Distress Syndrome - a Scoping Review

During the COVID-19 pandemic, specific COVID-19-related conditions renewed interest in the full-awake venovenous extracorporeal membrane oxygenation ( V-V ECMO) approach, in which ECMO is applied to awake, cooperative, and non-intubated patients. This scoping review aims to provide a descriptive overview of V-V ECMO in patients with COVID-19-related acute respiratory distress syndrome (CARDS). We searched the PubMed, Web of Science, and Scopus databases using the keywords "awake ECMO" or "spontaneous breathing AND ECMO", combined with "COVID-19", "SARS-CoV-2" or "coronavirus", utilizing the Boolean operator "AND". The search included papers published from November 1, 2019, to December 31, 2024. Sixty-four papers were assessed for eligibility at the abstract level, and fourteen articles (seven small-sample cohort studies and seven case reports) comprising 95 patients were included in the final analysis. The most frequent reasons for preferring V-V ECMO over mechanical ventilation were barotrauma and patient refusal of intubation and mechanical ventilation. The V-V ECMO strategy was successful (ie, patients not intubated, disconnected from ECMO, and discharged from the hospital) in 36.4% of cases (cohort studies only). The incidence of defined severe adverse events (bleeding, thrombosis, cannula malposition, delirium, and progression of barotrauma) was considered low. The mortality rate for CARDS patients treated with V-V ECMO (including only patients from cohort studies) reached 33.0%, notably lower than the 48% reported for CARDS patients treated with V-V ECMO in the ELSO registry. Patients who were intubated due to worsening respiratory failure during V-V ECMO had significantly higher mortality. Infectious complications, sepsis, and multiorgan failure were the most frequent causes of death. However, significant heterogeneity in the definitions and reporting of management, ECMO-related complications, and outcomes was observed across the papers. Despite the heterogeneity of the data, V-V ECMO in CARDS patients can be considered a safe approach associated with a lower mortality rate than that reported in the overall V-V ECMO CARDS population.