Will Mobile ECPR Change How EMS Treats Cardiac Arrest?

“He not busy being born, is busy dying.”—Bob Dylan (1965)

No one is busier dying than a patient in refractory ventricular fibrillation (RVF). These patients have exasperated EMS personnel for decades, and they, sadly, usually die. The treatment traditionally has been to administer ACLS for 30–45 minutes, and the lucky few who get a return of spontaneous circulation (ROSC) get admitted.

The survival rate using this approach has been around 8%.1 But, with the advent of adult, extracorporeal membrane oxygenation (ECMO), the approach to these patients may be changing.

JEMS: ECMO & ECPR

The use of ECMO in arrested patients has been referred to as extracorporeal cardiopulmonary resuscitation (ECPR). ECPR, coupled with the use of the LUCAS mechanical compression device, the ResQPOD impedance threshold device (ITD), and percutaneous cardiac intervention (PCI), has been used routinely for the past 2 1/2 years by Demetris Yannopoulos, MD, and his colleagues at the University of Minnesota.

EMS services in the Twin Cities, including the two largest providers, the St. Paul Fire Department and North Memorial Medical Transportation, which serve a combined population of 570,000, have been providing Yannopoulos with ECPR patients. The results of each resuscitation have been studied with results from the first 72 cases treated with this approach published last year in the Journal of the American College of Cardiology (JACC).1

Patient Selection

In order for a patient to be eligible for ECPR at the University of Minnesota, the initial recorded rhythm must be ventricular fibrillation (v fib) or ventricular tachycardia (v tach). In addition, the patient must be between the ages of 18 and 75, have no DNR orders or dementia, must be able to fit in the LUCAS, and must have an estimated transport time of less than 30 minutes.

Also, the estimated time from the 9-1-1 call to the coronary catheterization lab (CCL) must be under 90 minutes.

The patient isn’t eligible for ECPR if the family or caregiver declines, if there are any contraindications to mechanical CPR, if the patient has a known terminal illness, or is pregnant.

Table 1: Inclusion and exclusion criteria for University of Minnesota ECPR protocol

If these conditions are met, after three defibrillations and 300 mg of amiodarone, the patient is transported to the university’s CCL with ongoing automated CPR. The goal is to keep the scene time to a minimum (i.e., 10–12 minutes), much like a trauma scene, to get the patient to a center of resuscitation excellence as soon as possible.

In addition to the above inclusion criteria, upon arrival, the patient must have an EtCO2 greater than 10 mmHg, a PaO2 greater than 50 mmHg, an SaO2 greater than 85%, and a lactate of less than 18.

It should be noted that the arrest does not have to be witnessed in this protocol. The reason for this is that Yannopoulos and colleagues feel that v fib/v tach acts as a surrogate clock, i.e., v fib/v tach is usually short-lived, typically lasting 10 minutes or less.

So, if the patient is in a shockable rhythm when EMS arrives, the down time is probably under 10 minutes.

In addition, the patient doesn’t have to have signs of neurologic activity, as is required in a field ECPR trial currently underway in Paris.2

JEMS: How Physicians Perform Prehospital ECMO on the Streets of Paris

Besides Paris, there are a couple of other ECPR trials that should be mentioned. Although the CHEER Trial (which includes mechanical CPR, hypothermia, ECMO and early reperfusion) only had 11 patients with out-of-hospital cardiac arrest (OHCA) who received ECPR, five (45%) survived.3

The SAVE-J Trial (i.e., study of ACLS for v fib with extracorporeal circulation) was performed in Japan.4 This was a much larger study of v fib/v tach arrest. The authors reported on a total of 454 patients, of whom 260 received ECPR. Both CHEER and SAVE-J had much different designs than the Yannopoulos project, so comparing them is difficult. For example, in SAVE-J the patients were brought to 46 different hospitals and the trial employed a convenience randomization scheme (i.e., patients received ECPR based on whether they presented to an ECPR-capable center).

A thorough discussion of all of the trials in the literature is beyond the scope of this article. But suffice it to say, by and large the data and their results support the use of ECPR in OHCA.

Read complete article here.

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