Survival Odds Improving With Extracorporeal Membrane Oxygenation

Author: Monica Smith

Anesthesiology News

Once limited mainly to neonatal and pediatric populations, extracorporeal membrane oxygenation is gaining ground as a tool to rescue and manage adult patients with severe cardiac or respiratory failure who would otherwise likely die. Since establishing its own ECMO program in 2009, Montefiore Medical Center has supported patients across every discipline.

“A handful of the cases we saw in the last year were general surgery patients who developed acute respiratory distress syndrome (ARDS),” said Robert E. Michler, MD, the chairman of the Department of Surgery, chairman of the Department of Cardiothoracic and Vascular Surgery, and surgeon-in-chief at Montefiore Medical Center/Albert Einstein College of Medicine, in New York City.

“You don’t need to know the technical details, just know about the option and how to reach someone who is an expert in ECMO. You may have the opportunity to turn what seems like death into a survival.”

In many centers, general surgeons are the physicians who manage patients on ECMO. “And they’re often the best at it,” Robert Bartlett, MD, the founder of the Extracorporeal Life Support Organization (ELSO), a retired surgeon with the University of Michigan in Ann Arbor, and one of the original inventors of ECMO, said.

“ECMO started with general surgeons, myself and others, because general surgeons really developed surgical critical care. Of their own patients [who would be candidates for ECMO], the ones general surgeons see are their trauma patients with severe heart failure or lung failure or septic shock patients in profound shock,” Dr. Bartlett said.

Between 2006 and 2011, the use of ECMO has increased by more than 400%, partly due to increasing recognition of the therapy as a lifesaver, said William A. Jakobleff, MD, an assistant professor and the director of the Montefiore Institute for Minimally Invasive Surgery. “The reason for this is that it’s rapidly deployable and can be initiated quickly.”

Another factor contributing to the increased use of ECMO, especially since 2010, is improvement in the technology, which entails the use of a pump and oxygenator to support a patient’s heart or lungs. “The devices used for ECMO now are much safer and simpler than the devices used in the past. Nowadays it’s possible to have a patient on ECMO for a month or more,” Dr. Bartlett said.

While early trials of ECMO in adults showed no survival benefit and a high level of complications, numbers have improved. In addition to better technology, this improvement is largely due to greater physician experience and careful patient selection.

“Honestly, if you put a dying, asystolic person on venoarterial (VA) ECMO, they will die. Once multiorgan failure sets in, VA ECMO is not going to save that person. But if you put someone on ECMO who has a rhythm and provide the end organs with the perfusion they need, the end organs get better and those patients tend to survive,” Dr. Jakobleff said.

Worldwide, survival to discharge or transfer for ECMO patients is about 56%, but it varies by patient age and indications: from 29% for adults placed on ECMO after extracorporeal cardiopulmonary resuscitation to 73% for neonates placed on ECMO for pulmonary failure. “These are patients with a very high risk for mortality. That 60% to 70% survival compares with no survival at all otherwise,” Dr. Bartlett said.

At the 2018 Controversies, Problems and Techniques in Surgery meeting, Dr. Jakobleff discussed the types of ECMO, and when general surgeons should consider its use and what to do when they believe ECMO is warranted.

In patients with cardiac failure, VA ECMO supplies biventricular supports to the patient’s lungs and heart by allowing blood to circulate without going through the heart. It can be viewed as a bridge to recovery, transplantation or implantation of a ventricular assist device, or to manage refractory malignant arrhythmia.

In patients with cardiogenic shock due to myocardial infarction, myocarditis, peripartum cardiomyopathy or another mechanism, the indications for ECMO are hypotension with low cardiac output despite adequate intravascular volume, and shock that persists despite volume, inotropic intervention and vasoconstrictor support. “But the patient has to follow some commands, or at least have been witnessed following commands,” Dr. Jakobleff said.

ECMO is contraindicated, albeit not absolutely, in patients with nonrecoverable heart disease, those who are not candidates for transplantation or a permanent ventricular assist device, patients older than 70 years of age, those with chronic organ dysfunction, compliance issues, prolonged in-hospital cardiopulmonary resuscitation, or unwitnessed cardiac arrest in the field.

The goals are fairly straightforward. “We want to restore perfusion to the end organs; avoid LV [left ventricular] distention, pulmonary edema and hemorrhage; and eliminate or minimize vasopressors and inotropic support,” Dr. Jakobleff said.

He and his team do frequent ECHO assessments of patients on ECMO, and confirm limb perfusion within the first 24 hours—preferably sooner. “Honestly, with our vascular lab we get that confirmation within six hours of placing them on ECMO,” he said.

Venovenous ECMO, which supports the lungs only, can be considered for patients who have reached an extreme level of pulmonary distress due to any of the following conditions: pneumonia, bronchiolitis, ARDS, asthma and barotraumatic ventilation. The indications for ECMO are any hypotoxic respiratory failure due to any cause.

“You should consider ECMO when the risk of mortality is 50% or higher, and it is indicated if the risk of mortality exceeds 80%,” Dr. Jakobleff said.

Unlike VA ECMO, there are no contraindications for venovenous ECMO in pulmonary failure, but there are a number of criteria associated with poor outcomes.

“Someone who’s been maintained for seven days or more on mechanical ventilation with high settings, patients with major pharmacologic immunosuppression, recent or expanding CNS [central nervous system] hemorrhage, and patients with severe underlying chronic pathology have to be addressed on a case-by-case basis,” Dr. Jakobleff said.

Although ECMO may be a relatively rare entity, it is an important topic for general surgeons to be aware of, Dr. Michler said. “You need to think about this as a lifesaving measure for any of your patients who come down with critical, unexpected systemic disease that can be managed with ECMO support.”

Although more and more hospitals have ECMO, it is by no means universal. Whereas the cannulation itself can take as little as 10 minutes, management of a patient on ECMO is heavily resource-intensive.

“Cannulation can take place literally on the floor, on a bed, in an ICU; a group in France cannulated someone in a subway station,” Dr. Jakobleff said. “But rounding on these patients, monitoring the extremities—it takes a lot of work to get the survival levels we have. It’s not just the cardiac surgeon.”

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