Proper ECMO Configuration Essential for Patients Hospitalized With COVID-19

Older age and delayed time between intubation and ECMO initiation were associated with an increased risk of in-hospital mortality in patients with COVID-19.

During the first wave of the COVID-19 pandemic, in-hospital mortality occurred among approximately half of patients with severe COVID-19 infection who received extracorporeal membrane oxygenation (ECMO). Significant predictors for in-hospital mortality included older age, time between ECMO initiation, and use of inotropes and vasopressors. These study findings were published in The Lancet Respiratory Medicine.

Researchers across 21 countries in Europe conducted a prospective, multicenter study between March and September of 2020. Patients (N=1215) included were those hospitalized with polymerase chain reaction-confirmed COVID-19 infection who required ECMO. The primary outcomes were in-hospital mortality and mortality at 6 months following ECMO initiation. The researchers used mixed-Cox proportional hazards models to assess associations between patient- and management-related variables and the occurrence of in-hospital mortality.

Among 1215 patients included in the analysis, 78% were men, the median age was 53 (IQR, 46-60) years, and the median ECMO duration was 15 (IQR, 8-27) days. The most common comorbidities among these patients included arterial hypertension (47%), diabetes (27%), and cardiovascular disease (15%). Of these patients, 613 survived and in-hospital mortality occurred among 602.

The median time between intubation and initiation of ECMO was 4 days. Approximately 1105 (91%) patients received isolated venovenous ECMO, and the remaining patients required cardiorespiratory or cardiac support.

A total of 109 (11%) patients required ECMO reconfiguration. The most common complications necessitating reconfiguration were left ventricular failure, right ventricular failure, biventricular failure, and refractory hypoxemia. In 590 patients who underwent tracheostomy, the median time between intubation and the procedure was 16 (IQR, 8-25) days.

The percentage of patients who experienced major complications due to COVID-19 infection was significantly higher among those who died vs those who survived hospitalization (84% vs 65%; P <.0001). For patients who died, the most common cause of death was multiorgan failure (36%), followed by respiratory failure (27%), sepsis (12%), neurologic injury (12%), and cardiac arrest (6%).

[These] data shed light on the heart-lung interplay and the importance of choosing the right ECMO configuration, on the basis of the degree of cardiorespiratory compromise, in patients with COVID-19.

Multivariable models were used to determine factors associated with in-hospital mortality prior to and after ECMO initiation. Significant predictors of in-hospital mortality prior to ECMO initiation were older age (≥60 vs <60 years; adjusted hazard ratio [aHR], 1.68; 95% CI, 1.36-2.06), chronic kidney failure (aHR, 1.54; 95% CI, 1.07-2.24), use of inotropes (aHR, 1.62; 95% CI, 1.33-1.99) or vasopressors (aHR, 1.47; 95% CI, 1.12-1.88), and a time between intubation and ECMO initiation (≥4 days; aHR, 1.35; 95% CI, 1.12-1.62).

Significant predictors for in-hospital mortality following ECMO initiation included the need for ECMO reconfiguration (aHR, 1.39; 95% CI, 1.07-1.80), ischemic stroke (aHR, 1.66; 95% CI, 1.14-2.42), bowel ischemia (aHR, 1.52; 95% CI, 1.10-2.11), and chronic kidney failure (aHR, 1.45; 95% CI, 1.08-2.13).

The most common residual symptoms reported among patients at 6 months were dyspnea, cardiac symptoms, and neurocognitive symptoms.

Study limitations include the observational design, the lack of information on local ECMO protocols, and potential under-reporting in regard to ECMO complications.

According to the researchers, “[these] data shed light on the heart-lung interplay and the importance of choosing the right ECMO configuration, on the basis of the degree of cardiorespiratory compromise, in patients with COVID-19.

References:

Lorusso R, De Piero ME, Mariani S, et al. In-hospital and 6-month outcomes in patients with COVID-19 supported with extracorporeal membrane oxygenation (EuroECMO-COVID): a multicentre, prospective observational study. Lancet Respir Med. Published online November 16, 2022. doi:10.1016/S2213-2600(22)00403-9