When a patient is in refractory ventricular fibrillation (RVF), their survival chances are abysmal. They’ll typically get 30–45 minutes of ACLS, and if their blood begins flowing again, they can get admitted to a hospital. According to Ralph J. (R.J.) Frascone, MD, FACEP, FAEMS, professor of emergency medicine at the University of Minnesota and medical director for St. Paul-based Regions Hospital EMS, the survival rate using this approach has been around 5%–15% nationally.
However, the promise of extracorporeal membrane oxygenation (ECMO) may be changing the way EMS personnel and emergency department physicians handle these types of patients.
“We think there’s a chance it will change our approach to cardiac arrest, especially in regards to RVF,” says Frascone.
How ECMO Works
An ECMO machine is a type of heart-lung machine that uses a pump to circulate blood into an artificial lung, which oxygenates the blood and returns it to the patient. ECMO can support your heart, lungs, or both. It’s typically used as an emergency measure for critically ill patients. “We try to assess the possibility that a patient will survive, intact, before putting anyone on ECMO,” says Frascone.
When the patient’s native pulse and circulation are adequate, they can be taken off ECMO. If the patient cannot be taken off ECMO, life support is withdrawn. Patients can stay on EMCO anywhere from days to weeks, depending on several factors, including their diagnosis, severity, and response to the treatment.
Using ECMO in arrested patients is known as extracorporeal cardiopulmonary resuscitation (ECPR). Demetri Yannopoulos, MD, and his colleagues at the University of Minnesota have been using ECPR, coupled with LUCAS mechanical compressions, the ResQPOD impedance threshold device (ITD), and percutaneous cardiac intervention (PCI), for the past 2½ years.
“These are patients who are technically dead,” says Frascone. “This is a different ball game when ECMO is used on a patient who is full arrest. It’s an emergency situation, as opposed to an emergent situation, as it is in most patients who are not in full arrest. You really have to do this while CPR is ongoing and within minutes, if the patient is to have any chance of surviving.”
EMS services in the Twin Cities, including the St. Paul Fire Department and North Memorial Health, have been providing most of the patients Yannopoulos has treated with ECPR. The team has been evaluating the results of each resuscitation using the ECPR approach. A study was published last year in the Journal of the American College of Cardiology itemizing the results of the first 72 patients for whom ECPR was used.
To qualify as an ECPR recipient, the patient’s initial recorded rhythm must be ventricular fibrillation or tachycardia. Exclusion criteria for study purposes include age over 75 years, living in a nursing home, a current DNR order, pregnancy, inability to fit in the LUCAS, or diagnosis with terminal cancer. The most important inclusion criterion is that the estimated time from 9-1-1 call to ECMO placement must be under 90 minutes.
“These are the patients whom we don’t believe will have an intact survival,” says Frascone. “Our goal is not to just have our patients survive; we want them to survive neurologically intact.”
In the ongoing study of more than 225 patients, the neurologically intact survival rate has held around 40%—around 4 to 8 times the national average, he adds.
As with any medical treatment, ECMO poses some risks. “ECMO is not without complications. It has to be done by well-trained people who have a lot of experience,” Frascone says. “This is especially true when you’re doing it on an arrested patient, with ongoing CPR and time being critical. If a catheter isn’t placed right, a patient can die. Accidental decannulation and clotting can also happen, as well as stroke and infection.”
The Next Iteration of ECMO: Mobile Use
Frascone is currently working with others to create a mobile ECMO unit. This will be a community resource staffed by an experienced ECMO team, including a physician, nurse, and paramedic. The nurses and paramedics will train with the physicians.
The unit will be designed to get ECMO established, with all the necessary equipment in assigned and inventoried locations. It will have x-ray and fluoroscopy capability, multiple redundant power sources, fully redundant telemetry/communication support, and camera systems capable of advanced telemedicine. It will carry all necessary drugs, fluids, blood, and refrigeration.
One of the reasons for this new unit is time, says Frascone. ECMO should be started within 30 minutes of cardiac arrest.
“The point behind the mobile unit as a community resource is because ECPR takes so much training,” he says. “Any hospital in the region will be able to use the mobile unit and team. Since ECMO can be performed on the vehicle, this will take the load off the hospital. When a person is going on ECMO, the emergency department tends to be chaotic, because so many other things are happening. In addition, the team will be operating in a well-known milieu, in a guaranteed space where everything is in its place and readily available.”
The project will develop in three phases:
Phase 1 will involve just the ECMO team responding to a requesting hospital and performing the procedure in the emergency department;
Phase 2 will see the ECMO team and vehicle proceed to the hospital to which the arrested patient is being transported by standard ambulance. The patient will be transferred from that ambulance to the ECMO vehicle, where the procedure will be performed;
In phase 3 the vehicle and team will meet an incoming outer-ring ambulance at a designated rendezvous location, the patient will be transferred to the ECMO vehicle, and the procedure will be performed in the field.
“Most interestingly, if the ECMO team is staffed by an interventionalist that day, a PCI may also be done,” Frascone says. “The rationale for this is, once you’ve put the patient on ECMO, you’ve stabilized the brain, but the damage to the heart is still ongoing, and the sooner flow is established, the better.”
When the ECMO vehicle arrives at the hospital, it becomes part of that hospital, so the hospital maintains control of the patient—staff there can make all the decisions such as whether to do the PCI, along with if, when, and how to transfer the patient.
“We hope to have the first vehicle up and running by the end of the year,” says Frascone. “We hope to answer a lot of important questions, such as, is it worth it? What is the cost/benefit analysis? What kind of training does someone need to do this successfully? Also, do we need the actual vehicle, or is it enough to just have a responding ECMO team?”
If it’s successful, Frascone says they’ll add two more vehicles to cover the entire Twin Cities metro area and surrounding suburbs.
Daniel Casciato is a freelance writer and social media consultant from Pittsburgh, Pa. He makes his living writing about health, law, social media, and technology. Follow him on Twitter at @danielcasciato.