Weaning-Related Shock in Patients With ECMO: Incidence, Mortality, and Predisposing Factors.

OBJECTIVE

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) commonly is used to manage refractory cardiogenic shock after cardiac surgery, with 31% to 76% of patients successfully weaned off their ECMO. However, it is associated with high mortality rates, and 20% to 65% of weaned patients do not survive to hospital discharge. This study aimed to assess the incidence of ECMO weaning-related shock, the risk factors, and prognosis in the intensive care unit (ICU).

DESIGN

Retrospective observational cohort study.

SETTING

Surgical ICU of Cardiology Institute of Pitié-Salpêtrière University Hospital (Paris-France).

PARTICIPANTS

Patients who were assisted with a peripheral VA-ECMO from January 2015 to December 2017 were included. Patients with venovenous, central, or right ECMO were excluded.

MEASUREMENTS: The authors collected data on patients' characteristics, during and after surgery. The indications for VA-ECMO implantation were ventricular dysfunction, primary graft dysfunction, and refractory cardiac arrest. Weaning-related shock was defined as the need to introduce or increase the dose of catecholamine at ECMO explantation or in the following week.

RESULTS

After weaning off VA-ECMO, 56 of 146 patients (38.4%) presented weaning-related shock: 55% were septic shocks, 12.5 % were caused by right ventricle failure, and 7.1% by hemorrhage. ICU mortality was 42% versus 8% in patients who did not present shock. Multivariate analysis showed that patients with pulmonary hypertension and those with norepinephrine before weaning were more likely to develop shock.

CONCLUSION

ECMO weaning-related shock is frequent in patients with refractory cardiogenic shock after cardiac surgery. This is most commonly caused by sepsis and causes higher mortality rates, calling for further evaluation.