Time to Cannulation after ICU Admission Increases Mortality for Patients Requiring Veno-venous ECMO for COVID-19 Associated Acute Respiratory Distress Syndrome

Abstract

Objective: 

COVID-19 can cause ARDS that is rapidly progressive, severe, and refractory to conventional therapies. ECMO can be used as a supportive therapy to improve outcomes but evidence-based guidelines have not been defined.

Summary Background Data: 

Initial mortality rates associated with ECMO for ARDS in COVID-19 were high, leading some to believe that there was no role for ECMO in this viral illness. With more experience, outcomes have improved. The ideal candidate, timing of cannulation, and best postcannulation management strategy, however, has not yet been defined.

Methods: 

We conducted a retrospective review from April 1 to July 31, 2020 of the first 25 patients with COVID-19 associated ARDS placed on V-V ECMO at our institution. We analyzed the differences between survivors to hospital discharge and those who died. Modified Poisson regression was used to model adjusted risk factors for mortality.

Results: 

Forty-four patients (11/25) survived to hospital discharge. Survivors were significantly younger (40.5 years vs 53.1 years; P < 0.001) with no differences between cohorts in mean body mass index, diabetes, or PaO2:-FiO2 at cannulation. Survivors had shorter duration from symptom onset to cannulation (12.5 days vs 19.9 days, P = 0.028) and shorter duration of intensive care unit (ICU) length of stay before cannulation (5.6 days vs 11.7 days, P = 0.045). Each day from ICU admission to cannulation increased the adjusted risk of death by 4% and each year increase in age increased the adjusted risk 6%.

Conclusions: 

ECMO has a role in severe, refractory ARDS associated with COVID-19. Increasing age and time from ICU admission were risk factors for mortality and should be considered in patient selection. Further studies are needed to define best practices for V-V ECMO use in COVID-19.