Clinical Characteristics, Complications and Outcomes of Patients with Severe Acute Respiratory Distress Syndrome Related to COVID-19 or Influenza Requiring Extracorporeal Membrane Oxygenation—A Retrospective Cohort Study

Abstract

Extracorporeal membrane oxygenation (ECMO) represents a viable therapy option for patients with refractory acute respiratory distress syndrome (ARDS). Currently, veno-venous (vv) ECMO is frequently used in patients suffering from coronavirus disease 2019 (COVID-19). VV-ECMO was also frequently utilised during the influenza pandemic and experience with this complex and invasive treatment has increased worldwide since. However, data on comparison of clinical characteristics and outcome of patients with COVID-19 and influenza-related severe ARDS treated with vv-ECMO are scarce. This is a retrospective analysis of all consecutive patients treated with vv/(veno-arterial)va-ECMO between January 2009 and January 2021 at the University Medical Centre Hamburg-Eppendorf in Germany. All patients with confirmed COVID-19 or influenza were included. Patient characteristics, parameters related to ICU and vv/va-ECMO as well as clinical outcomes were compared. Mortality was assessed up to 90 days after vv/va-ECMO initiation. Overall, 113 patients were included, 52 (46%) with COVID-19 and 61 (54%) with influenza-related ARDS. Median age of patients with COVID-19 and influenza was 58 (IQR 53–64) and 52 (39–58) years (p < 0.001), 35% and 31% (p = 0.695) were female, respectively. Charlson Comorbidity Index was 3 (1–5) and 2 (0–5) points in the two groups (p = 0.309). Median SAPS II score pre-ECMO was 27 (24–36) vs. 32 (28–41) points (p = 0.009), and SOFA score was 13 (11–14) vs. 12 (8–15) points (p = 0.853), respectively. Median P/F ratio pre-ECMO was 64 (46–78) and 73 (56–104) (p = 0.089); pH was 7.20 (7.16–7.29) and 7.26 (7.18–7.33) (p = 0.166). Median days on vv/va-ECMO were 17 (7–27) and 11 (7–20) (p = 0.295), respectively. Seventy-one percent and sixty-nine percent had renal replacement therapy (p = 0.790). Ninety-four percent of patients with COVID-19 and seventy-seven percent with influenza experienced vv/va-ECMO-associated bleeding events (p = 0.004). Thirty-four percent and fifty-five percent were successfully weaned from ECMO (p = 0.025). Ninety-day mortality was 65% and 57% in patients with COVID-19 and influenza, respectively (p = 0.156). Median length of ICU stay was 24 (13–44) and 28 (16–14) days (p = 0.470), respectively. Despite similar disease severity, the use of vv/va-ECMO in ARDS related to COVID-19 and influenza resulted in similar outcomes at 90 days. A significant higher rate of bleeding complications and thrombosis was observed in patients with COVID-19.

Outcomes of Extracorporeal Membrane Oxygenation in COVID-19–Induced Acute Respiratory Distress Syndrome: An Inverse Probability Weighted Analysis

“…In our study, no differences were found in 28- and 60-day mortality between COVID-19–associated ARDS and non-COVID-19 ARDS, both unadjusted as adjusted for confounders. This is supported by previous studies showing equal survival at different time points ( 13 , 14 , 23 , 29 ). A recent study by Fanelli et al ( 23 ) found, when comparing patients receiving ECMO for either Influenza A H1N1 or COVID-19 ARDS, that 60-day mortality was only in the disadvantage of COVID-19 when unadjusted for confounders.…”

“…These differences may even be more important in the critically ill receiving VV ECMO. Although previous studies did not find differences in survival between patients receiving ECMO for COVID and non-COVID-ARDS, those studies are often small and correction for confounders is limited (13–15). Second, a change in patient outcomes over time in 2020 was found by different study groups, showing an increase in mortality in the second wave (16, 17).…”

Extracorporeal Membrane Oxygenation for COVID-19: Comparison of Outcomes to Non-COVID-19–Related Viral Acute Respiratory Distress Syndrome From the Extracorporeal Life Support Organization Registry

“…Few studies have directly compared mortality and complication rates for patients supported with ECMO for the management of COVID-19-related ARDS versus non-COVID-19-related viral ARDS. Studies with such direct comparisons have used small sample sizes and reached varying conclusions (7)(8)(9)(10)(11)(12).…”

Mortality rates of severe COVID-19-related respiratory failure with and without extracorporeal membrane oxygenation in the Middle Ruhr Region of Germany

“…Compared to ARDS of other etiology COVID-19 patients with ECMO support stay longer on ICU 6 . Increased length of ICU stay and mortality are worrying, especially in the pre-vaccination era.…”