Evidence mounts for ECMO in patients with severe COVID-19 respiratory failure

Two recently published studies report success with extracorporeal membrane oxygenation support in patients with acute respiratory distress syndrome associated with COVID-19.

In a retrospective cohort study published in The Lancet Respiratory Medicine, researchers analyzed clinical characteristics and outcomes of 492 patients treated with ECMO for COVID-19-associated ARDS at five ICUs within the Paris-Sorbonne University Hospital Network from March 8 to May 2. The researchers reported complete day-60 follow-up for 83 patients (median age, 49 years; 73% men) who received ECMO.

Before ECMO, 94% of patients were prone positioned (median driving pressure, 18 cm H₂O; ratio of arterial oxygen partial pressure to fractional inspired oxygen, 60 mm Hg). Sixty days after initiation of ECMO, the researchers’ estimated probability of death was 31% and the probability of being alive and out of the ICU was 45%.

During the study period, major bleeding occurred in 42% of patients and hemorrhagic stroke in 5%. Thirty patients died.

“The survival of EMCO-rescued very sick patients with COVID-19 was similar to that reported in studies on EMCO support for severe ARDS published in the past few years,” Matthieu Schmidt, MD, assistant professor at the Institute of Cardiometabolism and Nutrition at Sorbonne University, Paris, and colleagues wrote. “Should another COVID-19 wave occur, ECMO should be considered at an early stage for patients developing profound respiratory failure, despite optimized conventional care, including prone positioning.”

In a research letter published in JAMA Surgery, researchers in Chicago reported their experience using single-access, dual-stage venovenous ECMO with an emphasis on early extubation.

Forty consecutive patients (mean age, 48.4 years; 75% men; 40% Black; 45% Hispanic) with COVID-19 and severe respiratory failure were treated with EMCO at two tertiary medical centers in Chicago from March 17 to July 17. In all patients, a single-access, dual-stage right atrium-to-pulmonary artery cannula was implanted, after which ventilation was discontinued while the patient continued ECMO support, according to the study.

All patients reached maximum ventilator support, according to the researchers. Ninety percent of patients were placed in prone position (73%), paralyzed (78%) or both before ECMO. Sixty percent of patients required vasopressors.

Primary outcome was survival with safe discontinuation of both ventilatory and ECMO support. The researchers reported that, as of July 17, all patients had successful discontinuation of ventilator support (mean time from ECMO initiation to extubation, 13 days). In total, 32 (80%) patients were no longer receiving ECMO support as of July 17 and 29 (73%) patients were discharged without requiring oxygen.

Six patients (15%) died during the study period.

The researchers noted several advantages of the single-access, dual-stage cannula described in this study, including direct pulmonary artery flow, early mobility after ventilation, minimal complications or revisions and support of the right side of the heart.

“The limited studies on patients with COVID-19 requiring ECMO have thus far demonstrated poor survival. Overall, this study demonstrates positive outcomes, with most patients alive and no longer receiving ventilator care and ECMO support and 73% discharged and no longer receiving oxygen,” Asif K. Mustafa, MD, PhD, cardiothoracic surgeon in the department of cardiovascular and thoracic surgery at Rush University Medical Center and Cardiothoracic and Vascular Surgery Associates at Advocate Christ Medical Center, Illinois, and colleagues wrote.

Mustafa and colleagues noted limitations of their research, including the small number of patients, and noted that further research is required to elucidate the long-term outcomes of the approach studied.

“Single-access, dual-stage venovenous ECMO with early extubation appears to be safe and effective in patients with COVID-19 respiratory failure,” the researchers concluded.

Reference:

Mustafa AK, et al. JAMA Surg. 2020;doi:10.1001/jamasurg.2020.3950.