ECMO Duration for COVID-19 Patients - Does it Matter?

Objective: ECMO has acceptable outcomes for severe ARDS and is used for COVID-19 ARDS. This study investigated whether duration of ECMO supported its long-term usage. Method(s): A retrospective, IRB approved single-center study was conducted to review all patients placed on ECMO for refractory ARDS due to COVID-19 from 3/1/2020, to 3/1/2022. The review included demographics, ECMO run days, length of hospital stay, discharge disposition, and mortality (defined as in hospital death). Patient ECMO runs were binned into two categories based on days of ECMO support. Short Runs (SR) were defined as <= 30 days;Long Runs (LR) were > 30 days. Result(s): Overall, 164 patients and 165 ECMO runs comprised the study cohort. Demographics, age, and degree of respiratory failure were similar for both groups. SR were 15.7 days;LR were 80.6 days (p<0.01). Mortality was similar amongst the SR and LR groups (46.9% vs 39.3%, NS) despite duration of support. Discharge location was similar amongst both groups, but LR patients tend to require more use of long-term care (26.2% vs 18.5%, NS). LR was associated with increased use of cannulas (2.1 vs 3.1, p<0.01), increased membrane lungs (1.1 vs 2.9, p<0.01), and increased hospital stay days (94.8 vs 28.4, p<0.01). Conclusion(s): Our study demonstrated that duration of ECMO in COVID-19 was not a factor in mortality. LR patients experienced increased use of resources (cannulation, membrane lungs and length of stay) and were discharged to long term care facilities more often. More studies are needed to explore other aspects of survival.

Comparison of cannulation approaches for venovenous extracorporeal membrane oxygenation during covid-19

Purpose: Venovenous extracorporeal membrane oxygenation (VV-ECMO) is performed through various cannulation approaches but an optimal strategy remains uncertain. Methods: A retrospective, multi-center study was conducted. Adult patients (≥18 years old) placed on VV-ECMO for severe respiratory failure due to COVID-19 between March 1, 2020, to April 30, 2021, across the United States were included. Patients were divided into the following 3 groups based on initial cannulation: 1) femoral vein-femoral vein or femoral vein-internal jugular vein (Dual-Site, DS), 2) single, dual-lumen cannula in internal jugular vein with tip positioned in the pulmonary artery (PA) and 3) single, dual-lumen cannula in internal jugular vein with tip positioned in the inferior vena cava (IVC). The primary outcome was in-hospital mortality after VV-ECMO placement assessed by a time-toevent analysis. Results: Overall, 435 patients from 17 centers comprised the study cohort. DS cannulation was performed in 247 (age: 47±11, 30% female) cases, 99 (age 50±12, 26% female) received PA, and 89 patients got IVC (age 45±12, 33% female). At 90 days, in-hospital mortality across cannulation groups was 60% (DS), 41% (PA) and 61% (IVC), p=0.06 (Figure 1). After adjustment for clinical covariates, the likelihood of in-hospital mortality in comparison to DS, was lower with PA (aHR: 0.60, 95%CI 0.40-0.91, p=0.02) and similar with IVC (aHR: 0.99, 95%CI 0.68-1.43, p=0.95). Conclusion: Catheter directed flow into the PA with a single dual-lumen cannula is associated with reduced mortality during VV ECMO for COVID-19.

Direct versus indirect thrombin inhibition during extracorporeal membrane oxygenation support for covid-19

Purpose: Anticoagulation during extracorporeal membrane oxygenation (ECMO) for COVID-19 can be carried out by direct or indirect thrombin inhibition. The former agent obviates monitoring of antithrombin III but differences in outcomes with either approach are uncertain. Methods: A retrospective, multi-center study was conducted. Adult patients (≥18 years old) placed on ECMO for severe respiratory or circulatory failure due to COVID-19 between March 1, 2020, to April 30, 2021, in the United States were included. Patient were divided in 2 groups based on the utilized anticoagulation agent during ECMO support: 1) direct thrombin inhibitor (DTi, e.g. bivalirudin and argatroban) and 2) indirect thrombin inhibitor (IDTi, e.g. unfractionated heparin). The primary outcome was in-hospital mortality after ECMO placement assessed by a time-to-event analysis. Results: Overall, 455 patients from 17 centers were placed on ECMO, of whom 44 were excluded due to no reported anticoagulation agent. DTi was used in 160 (age: 47±11, 28% female) cases and 251 patients received IDTi (age 47±12, 29% female). At 90 days, in-hospital mortality was 50% (DTi) and 61% (IDTi), p=0.08, (Figure). After adjustment for clinical covariates, the likelihood of in-hospital mortality was similar with DTi (aHR: 0.79, 95%CI 0.57-1.10, p=0.16) compared to IDTi. Noted prevalence of deep vein thrombosis (DTi 14%, IDHi 12%), ischemic stroke (DTi 2%, IDHi 3%), intracranial hemorrhage (DTi 11%, IDHi 10%) and bleeding requiring transfusion (DTi 71%, IDHi 83%) was comparable between groups. Conclusion: Anticoagulants that directly or indirectly inhibit thrombin are associated with similar outcomes during ECMO for COVID-19.