key: cord-0991802-alnbcko8
authors: Ortoleva, Jamel; Dalia, Adam A.
title: Long-term Outcomes are Important: Extracorporeal Membrane Oxygenation for COVID-19
date: 2021-02-24
journal: J Cardiothorac Vasc Anesth
DOI: 10.1053/j.jvca.2021.02.044
sha: 27877a3b7ac8dd48c4cfa5a98e538e01a271d028
doc_id: 991802
cord_uid: alnbcko8

nan

mortality at six months; with a reported six-month mortality of 53% (70/132). From the 132 patient cohort, 10 patients were supported with VA-ECMO, making it challenging to draw conclusions from this subgroup. The importance of this work goes beyond the presentation of six-month outcomes; the authors were also able to identify pre-ECMO cannulation determinants of six-month outcomes. Age and arterial pH before cannulation for ECMO were associated with an increased risk of mortality at six months. Patients ≥ 60 years old and patients with a pH < 7.23 were found to have a higher six-month mortality. This work offers much needed insight into the long-term outcomes (6 months) of patients requiring ECMO for COVID-19 related ARDS.

When a patient or family member asks us: "How will my life be different in six months, how close to baseline will I be?" with regard to ECMO, it is frustratingly difficult to answer this question. ECMO has been utilized for over 30 years yet unfortunately, very little is known about long term outcomes such as physical capability, daily life, life expectancy, neurologic outcomes, psychiatric outcomes, and overall quality of life. When we initiate mechanical ventilation, begin renal replacement therapy, deploy ECMO or utilize other major life support interventions, we should always consider what the patient will be capable of in the long term after surviving their critical illness.

Large cohorts of formerly hospitalized non-ECMO COVID-19 patients that were subsequently discharged alive are being studied for long term effects; these patients are also known as long haulers. In one large review by Huang et al of 1,733 patients queried for symptoms six months after hospital discharge, 63% continued to suffer from fatigue or muscle weakness, 26% had difficulty with sleep and 23% percent reported psychiatric symptoms of anxiety or depression. 2 In the same study, Huang et al found that many patients remained physically compromised with more than 20% displaying below normal performance on a 6 minute walk test. 2 In contrast, the majority of literature on ECMO outcomes, particularly in relation to COVID-19, focuses on survival to discharge, or a short period thereafter (30 days). A recent study by Barbaro et al examined the ECMO outcomes in COVID-19 from the Extracorporeal Life Support Organization (ELSO) international database; a mortality of 39% (survival of 61%) was noted in patients with complete data for their hospitalization. 3 In the same study, Barbaro requiring ECMO is difficult to obtain given that the disease was first recognized in late 2019.

Beyond survival, quality of life is rarely available on a large scale and is limited to smaller reviews of data. In order to obtain a deeper and more meaningful understanding of life after ECMO, longer-term follow up is required to paint a realistic picture to patients and their family members. Long-term survival, especially with good functional status, for any major intervention during hospitalization should be one of the most important metrics to define a success rate.

Retaining near baseline functional status is most reflective of a meaningful and successful intervention. Long-term survival after VV ECMO in cohorts requiring support for indications other than COVID-19 has been described but further work is certainly needed. 5, 6 To that end, in a retrospective review of 255 patients, von Bahr et. al found a survival to discharge of 64%, 90 day survival of 55%, and a one year survival of 52%. 6 In a similar review of ECMO long term outcomes in 84 patients (33 of which received VV ECMO for respiratory failure) 66.7% of ECMO patients were alive at one year. 5 

with that of von Bahr in the pre-COVID-19 era.

With thousands of patients already having undergone ECMO support for COVID-19 pneumonia, the contribution by Biancari et al is the first of what we hope to be a series of works that sheds light on the important subject of life after ECMO for COVID-19. Many questions remain regarding long-term recovery from ECMO for the most critically ill patients that survive. COVID-19 is a multisystem disease and as such has multiple sequelae. For example, preliminary work on COVID-19 patients in the early period after recovery from hospitalization found that pulmonary function tests frequently display a pattern of a restrictive defect. 7, 8 Given that the lung function of patients on ECMO for refractory hypoxemia due to COVID-19 pneumonia are among the most compromised, these patients should be followed in order to better characterize the frequency and extent of lingering lung pathology. Additionally, understanding the timescale of tracheostomy decannulation is important as a means of informing patients and family members about what to expect.

Extrapulmonary effects of COVID-19 require better long-term understanding as well. The risk of thromboembolic phenomenon in COVID-19 patients may be higher than other critically ill patients, and as such, understanding the duration of this hypercoagulable state is an important and unanswered question. 9 It is especially relevant to understand the long term sequelae of this thrombotic state in decannulated ECMO patients because of the high risk of cannula associated deep vein thrombosis in all ECMO patients, let alone those with COVID-19. Renal dysfunction is common in ECMO patients, understanding the frequency, recovery, and the effects on outcome will be important for prognostication in patients with COVID-19 supported by ECMO. Finally, it is known that post-traumatic stress disorder and chronic pain are common among patients recovering from critical illness; the added difficulty of limited visitation takes an enormous toll on patients and their families' mental wellbeing. 10 Understanding the long-term psychiatric effects of critical illness in the COVID-19 ECMO population will be extremely important to inform practices for prevention and treatment.

Another aspect of the COVID-19 ECMO patient population that has not been thoroughly explored is the duration of VV ECMO support and its effects on long term mortality. Biancari et al reported a mean duration of ECMO support of 14.6 days; the duration of support did not differ between the six-month survivors and non survivors. This reported duration of 14.6 days is similar to the pre-COVID ARDS ECMO duration of 15 days. 11 This new data can potentially help answer the question of "What is a reasonable amount of time to keep COVID-19 patients on ECMO support?"

The COVID-19 pandemic continues to exert significant stress on healthcare systems worldwide.

Although ECMO patients represent a very small percentage of those infected with COVID-19, they represent an important population at the extremes of illness due to this novel disease.

Although it is a relatively small study, Biancari et al have nonetheless taken an important step towards describing the long-term outcomes of patients requiring ECMO for COVID-19. It is very likely that the work by Huang et al represents a less severe glimpse of what will be found in COVID-19 patients supported with ECMO; we expect more patients with physical compromise, psychiatric abnormalities, and other multisystem dysfunction. 2 As the COVID-19 pandemic continues to evolve, we hope to see more research detailing the chronic effects of COVID-19 in the unique subgroup of patients requiring ECMO support.

Six-Month Survival After Extracorporeal Membrane Oxygenation for Severe COVID-19

6-month consequences of COVID-19 in patients discharged from hospital: a cohort study

Extracorporeal membrane oxygenation support in COVID-19: an international cohort study of the Extracorporeal Life Support Organization registry

Extracorporeal membrane oxygenation in patients with severe respiratory failure from COVID-19

Quality of Life and Lung Function in Survivors of Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome

Long-Term Survival in Adults Treated With Extracorporeal Membrane Oxygenation for Respiratory Failure and Sepsis*: Critical Care Medicine

Follow-up study of the pulmonary function and related physiological characteristics of COVID-19 survivors three months after recovery

Pulmonary function in patients surviving to COVID-19 pneumonia

Thrombosis in Hospitalized Patients With COVID-19 in a New York City Health System

Neurological and neuropsychiatric complications of COVID-19 in 153 patients: a UK-wide surveillance study

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome