Choosing the right reference cohort for assessing outcome of venovenous ECMO

Outcomes of patients with coronavirus disease versus other lung infections requiring venovenous extracorporeal membrane oxygenation

Background

Patients with Coronavirus Disease (COVID-19) often develop severe acute respiratory distress syndrome (ARDS) requiring prolonged mechanical ventilation (MV), and venovenous extracorporeal membrane oxygenation (V-V ECMO).Mortality in COVID-19 patients on V-V ECMO was exceptionally high; therefore, whether survival can be ameliorated should be investigated.

Methods

We collected data from 85 patients with severe ARDS who required ECMO support at the University Hospital Magdeburg from 2014 to 2021. The patients were divided into the COVID-19 group (52 patients) and the non-COVID-19 group (33 patients). Demographic and pre-, intra-, and post-ECMO data were retrospectively recorded. The parameters of mechanical ventilation, laboratory data before using ECMO, and during ECMO were compared.

Results

There was a significant difference between the two groups regarding survival: 38.5% of COVID-19 patients and 63.6% of non-COVID-19 patients survived 60 days (p = 0.024). COVID-19 patients required V-V ECMO after 6.5 days of MV, while non-COVID-19 patients required V-V ECMO after 2.0 days of MV (p = 0.048). The COVID-19 group had a greater proportion of patients with ischemic heart disease (21.2% vs 3%, p = 0.019). The rates of most complications were comparable in both groups, whereas the COVID-19 group showed a significantly higher rate of cerebral bleeding (23.1 vs 6.1%, p = 0.039) and lung bacterial superinfection (53.8% vs 9.1%, p = <0.001).

Conclusion

The higher 60-days mortality among patients with COVID-19 with severe ARDS was attributable to superinfection, a higher risk of intracerebral bleeding, and the pre-existing ischemic heart disease.

The role of ECMO in COVID-19 acute respiratory failure: Defining risk factors for mortality

BACKGROUND

Veno-venous extracorporeal membrane oxygenation (VV ECMO) utilization increased substantially during the COVID-19 pandemic, but without patient selection criteria.

METHODS

We conducted a retrospective review of all adult patients with COVID-19-associated ARDS placed on VV ECMO at our institution from April 2020 through June 2022.

RESULTS

162 patients were included (n = 95 Pre-Delta; n = 58 Delta; n = 9 Omicron). The frequency of ECMO duration greater than three weeks was variable by pandemic period (17% pre-Delta, 41% Delta, 22% Omicron, p = 0.003). In-hospital mortality was 60.5%. Age ≥50 years (RR 1.28, 95% CI 1.01, 1.62), ≥7 days of respiratory support (1.39, 95% CI 1.05, 1.83) and pre-cannulation renal failure requiring dialysis (RR 1.42, 95% CI 1.13, 1.78) were associated with mortality.

CONCLUSIONS

In this cohort of VV ECMO patients with COVID-19, older age, a longer duration of pre-ECMO respiratory support, and pre-ECMO renal failure all increased the risk of mortality by approximately 30%.

Extracorporeal membrane oxygenation during the first three waves of the coronavirus disease 2019 pandemic: A retrospective single-center registry study

BACKGROUND

Despite increasing knowledge about the optimal treatment for patients with severe COVID-19, data from different cohorts suggested that survival of patients treated with ECMO seemed to decline over the course of the pandemic.

METHODS

In this non-interventional retrospective single-center registry study we analyzed all consecutive patients tested positive for SARS-CoV-2 infection and supported with VV ECMO in our center during the first three waves of the pandemic. From March 2020 through June 2021, 59 patients have been included.

RESULTS

Overall 90-day survival was 32%. Besides changes in drug treatment for COVID-19 and a lower PaO₂ /FiO₂ ratio before ECMO initiation during the third wave, all other patient baseline characteristics were similar during the three waves. Survival rate was highest during the first wave and lowest during the third wave, yet this difference was not statistically significant.

CONCLUSIONS

VV ECMO has shown to be a feasible and safe support option for patients with severe respiratory failure due to COVID-19. The results from this single-center study confirm findings from other cohorts showing declining survival rates of patients treated with VV ECMO during the COVID-19 pandemic, however, the specific reasons for this finding remain unclear.

Extracorporeal membrane oxygenation during the first three waves of the coronavirus disease 2019 pandemic - a retrospective single-center registry study

Background

Despite increasing knowledge about the optimal treatment for patients with severe COVID‐19, data from different cohorts suggested that survival of patients treated with ECMO seemed to decline over the course of the pandemic.

Methods

In this non‐interventional retrospective single‐center registry study we analyzed all consecutive patients tested positive for SARS‐CoV‐2 infection and supported with VV ECMO in our center during the first three waves of the pandemic. From March 2020 through June 2021, 59 patients have been included.

Results

Overall 90‐day survival was 32%. Besides changes in drug treatment for COVID‐19 and a lower PaO₂/FiO₂ ratio before ECMO initiation during the third wave, all other patient baseline characteristics were similar during the three waves. Survival rate was highest during the first wave and lowest during the third wave, yet this difference was not statistically significant.

Conclusions

VV ECMO has shown to be a feasible and safe support option for patients with severe respiratory failure due to COVID‐19. The results from this single‐center study confirm findings from other cohorts showing declining survival rates of patients treated with VV ECMO during the COVID‐19 pandemic, however, the specific reasons for this finding remain unclear.

Respiratory indications for ECMO: focus on COVID-19

Extracorporeal membrane oxygenation (ECMO) is increasingly being used for patients with severe respiratory failure and has received particular attention during the coronavirus disease 2019 (COVID-19) pandemic. Evidence from two key randomized controlled trials, a subsequent post hoc Bayesian analysis, and meta-analyses support the interpretation of a benefit of ECMO in combination with ultra-lung-protective ventilation for select patients with very severe forms of acute respiratory distress syndrome (ARDS). During the pandemic, new evidence has emerged helping to better define the role of ECMO for patients with COVID-19. Results from large cohorts suggest outcomes during the first wave of the pandemic were similar to those in non-COVID-19 cohorts. As the pandemic continued, mortality of patients supported with ECMO has increased. However, the precise reasons for this observation are unclear. Known risk factors for mortality in COVID-19 and non-COVID-19 patients are higher patient age, concomitant extra-pulmonary organ failures or malignancies, prolonged mechanical ventilation before ECMO, less experienced treatment teams and lower ECMO caseloads in the treating center. ECMO is a high resource-dependent support option; therefore, it should be used judiciously, and its availability may need to be constrained when resources are scarce. More evidence from high-quality research is required to better define the role and limitations of ECMO in patients with severe COVID-19.