ECMO During COVID-19: A Society of Thoracic Surgeons/Extracorporeal Life Support Organization Survey

BACKGROUND

The Society of Thoracic Surgeons Workforce on Critical Care and the Extracorporeal Life Support Organization sought to identify how the coronavirus disease 2019 (COVID-19) pandemic has changed the practice of venoarterial (VA) and venovenous (VV) extracorporeal membrane oxygenation (ECMO) programs across North America.

METHODS

A 26-question survey covering 6 categories (ECMO initiation, cannulation, management, anticoagulation, triage/protocols, and credentialing) was emailed to 276 North American Extracorporeal Life Support Organization centers. ECMO practices before and during the COVID-19 pandemic were compared.

RESULTS

Responses were received from 93 (34%) programs. The percentage of high-volume (>20 cases per year) VV ECMO programs increased during the pandemic from 29% to 41% (P < .001), as did institutions requiring multiple clinicians for determining initiation of ECMO (VV ECMO, 25% to 43% [P = .001]; VA ECMO, 20% to 32% [P = .012]). During the pandemic, more institutions developed their own protocols for resource allocation (23% before to 51%; P < .001), and more programs created sharing arrangements to triage patients and equipment with other centers (31% to 57%; P < .001). Direct thrombin inhibitor use increased for both VA ECMO (13% to 18%; P = .025) and VV ECMO (12% to 24%; P = .005). Although cardiothoracic surgeons remained the primary cannulating proceduralists, VV ECMO cannulations performed by pulmonary and critical care physicians increased (13% to 17%; P = .046).

CONCLUSIONS

The Society of Thoracic Surgeons/Extracorporeal Life Support Organization collaborative survey indicated that the pandemic has affected ECMO practice. Further research on these ECMO strategies and lessons learned during the COVID-19 pandemic may be useful in future global situations.

Venovenous Extracorporeal Membrane Oxygenation for Patients With Return of Spontaneous Circulation After Cardiac Arrest Owing to Acute Respiratory Distress Syndrome

OBJECTIVE

The primary objective of this study was to determine the survival to hospital discharge of patients who were treated with venovenous (VV) extracorporeal membrane oxygenation (ECMO) for respiratory failure after cardiac arrest.

DESIGN

Retrospective chart review.

SETTING

University-affiliated tertiary care hospitals.

PARTICIPANTS

The study comprised 21 patients.

INTERVENTIONS

Implementation of VV ECMO in patients with return of spontaneous circulation after cardiac arrest owing to respiratory insufficiency.

MEASUREMENTS AND MAIN RESULTS

The most common etiology of arrest was pneumonia-associated acute respiratory distress syndrome (8/21 [38%]). Overall, 12/21(57%) patients survived to hospital discharge. Two of 12 (17%) patients required hemodialysis upon discharge.

CONCLUSION

VV ECMO may be an appropriate alternative to venoarterial ECMO in select patients with return of spontaneous circulation after cardiac arrest owing to profound respiratory failure.

Identification of minimal enhancer elements sufficient for Pax3 expression in neural crest and implication of Tead2 as a regulator of Pax3

Pax3 is a transcription factor that is required by Pre-migratory neural crest cells give rise to the peripheral nervous system, melanocytes, some vascular smooth muscle, and numerous other derivatives. These cells require the transcription factor Pax3, and both mice and humans with Pax3 deficiency exhibit neural crest-related developmental defects. Pax3 is also expressed in the dorsal neural tube, and by myogenic progenitors in the presomitic mesoderm and the hypaxial somites. Molecular pathways that regulate Pax3expression in the roof plate probably represent early upstream signals in neural crest induction. We have identified an enhancer region in the Pax3 genomic locus that is sufficient to recapitulate expression in neural crest precursors in transgenic mice. We show that Tead2, a member of the Tead box family of transcription factors, binds to a neural crest enhancer and activates Pax3 expression. Tead2, and its co-activator YAP65, are co-expressed with Pax3 in the dorsal neural tube, and mutation of the Tead2 binding site in the context of Pax3 transgenic constructs abolishes neural expression. In addition, a Tead2-Engrailed fusion protein is able to repress retinoic acid-induced Pax3 expression in P19 cells and in vivo. These results suggest that Tead2 is an endogenous activator of Pax3 in neural crest.

Correlation of the cardiogenic air flow in the respiratory airway (i.e. the pneumocardiogram) with left ventricular stroke volume in dogs

The pneumocardiogram (PNCG) is a record of the pulsatile flow of air in the trachea coincident with each heart beat. In 5 anesthetized mongrel dogs, the cardiogenic air flow through an endotracheal tube was measured with a research pneumotachograph. The correlation between the pneumocardiographic volume of air, obtained by integrating the PNCG over the period of ventricular ejection, and stroke volume (SV), measured by the saline-dilution method, was determined for a physiologic range of SV. Although the pneumocardiographic volume tracked measured SV, the former was always less. The range of correlation coefficients was 0.60 to 0.91. The results suggest that the PNCG may be suitable for continuous tracking of changes in SV on a noninvasive, beat-by-beat basis. The technique is ideally applicable to intubated human subjects, particularly those undergoing closed-chest surgical procedures.