Is emergency medicine on the verge of “the dawn of a new golden age of resuscitation?” That's the bold prediction from CPR innovator Keith Lurie, MD, a professor of internal and emergency medicine at the University of Minnesota, a director of the CentraCare Heart and Vascular Center and the founder of Minnesota Resuscitation Solutions.
“I think that the CPR world has reached a new place in the evolution and diagnosis and treatment of cardiac arrest, where we now have the tools available to markedly improve outcomes after an arrest,” he said. “Our next challenge is to refine those tools and implement them widely.”
Emergency physicians, EMS personnel, and other experts from around the world gathered to discuss these recent advances in resuscitation science and clinical practice at the inaugural State of the Future of Resuscitation Conference held in September. A task force report aimed at creating a blueprint for resuscitation for clinicians, with a focus on prehospital advances, will be published before the end of the year in Journal of Emergency Medical Services, Dr. Lurie said.
Plenty of controversies remain; for demonstration of that, look no further than the recent lively debate on the EMCrit podcast between host Scott Weingart, MD, a professor of emergency medicine and the chief of emergency critical care at Stony Brook School of Medicine, and Howard Mell, MD, the chair of the ACEP subcommittee on EMS Education and a reservist emergency physician with Vituity, on whether out-of-hospital cardiac arrests should be transported or terminated in the field. (See box, “Resuscitation Reality.”)
But, Dr. Lurie said, there's much to agree on, especially about recent advances within the past several years.
Diagnosing a Viable Patient
Some obvious and well-known factors help to predict which arrest patients have a reasonable chance of surviving more or less neurologically intact. “There's a world of difference between an 80-year-old in a nursing home with stage 4 lung cancer and a 45-year-old who collapses behind the lawnmower in a witnessed arrest,” said Dr. Mell. “The first couple of steps we take in an arrest for most patients are almost always the same, but after that, we need a more reliable system of deciding who really is viable.”
New research has added valuable prognostic indicators to these factors and other standards such as shockable rhythm, Dr. Lurie said. A 2017 study, for instance, found that spontaneous gasping—agonal respiration—during CPR was independently associated with increased one-year survival with a cerebral performance score (CPC) of 2 or less. (J Am Coll Cardiol 2017;70:1467; http://bit.ly/2R5efmT.) Up to 20 percent of patients are noted to gasp during CPR, said Dr. Lurie, an author of the paper. “Patients who gasp and have a shockable rhythm are 57 times likelier to survive intact at a year than those with no gasping and no shockable rhythm,” he said. “When you observe these gasps, that transmits the message, ‘Hey, don't give up on this patient.’”
Research also indicates that an end-tidal expiratory pressure of CO2 (ETCO2) reading in the prehospital phase is a strong predictor of neurologic outcome in out-of-hospital arrests; an ETCO2 of 30-40 mm Hg is associated with a better prognosis. (Resuscitation 2018Sep 22. doi: 10.1016/j.resuscitation.2018.09.018.)
“If your ETCO2 is low after 10-20 minutes, that's a very bad sign, to the point that it is useful for deciding to terminate resuscitation,” said Jeff Jarvis, MD, EMT-P, an emergency physician at Baylor Scott & White Hospital in Round Rock, TX, and the medical director for Williamson County EMS. “And if you have low initial ETCO2 and see it spike during resuscitation, that's a good sign that you're about to get pulses back and achieve ROSC.”
A blood marker, neuron-specific enolase, however, is not a field prognostic indicator but can be used in the ED, along with lactate, as a predictor of long-term neurologic survival and who is more likely to benefit from more advanced interventions such as extracorporeal membrane oxygenation (ECMO).
CPR Training and Techniques
Most people do not go into cardiac arrest with an EMS team or emergency physician at hand, and their chance of surviving neurologically intact often depends on whether someone nearby knows how to perform CPR properly. Unfortunately, that is all too often not the case, a fact illustrated by two numbers from the American Heart Association: 90 percent, the overall fatality rate for out-of-hospital cardiac arrest, and 45 percent, the percentage of arrest victims who survive when bystander CPR is administered. (CPR Facts and Stats; http://bit.ly/2DAtamr.)
“The biggest bang for your resuscitation buck, bar none, is to train a large proportion of your population in CPR,” Dr. Mell said. “When you have higher rates of CPR attempted, you get way better outcomes overall. It's not all that sexy, but there's nothing as effective. We were able to train 10,000 people in Lake County [IL] in CPR in one year—we met them at football games, county fairs, in the mall.”
The key to improving outcomes is the simplicity and effectiveness of teaching hands-only CPR, which is also what Dr. Mell told the EMS crews to do in Lake and Newark counties, where he formerly served as medical director. Survival rates for cardiac arrest victims initially cared for by fire and EMS crews went from 9.3 percent to 19.15 percent a year after implementing CPR with an emphasis on early defibrillation, he said.
“The largest percentage of patients you will get back in the first ten minutes with good CPR and early defibrillation,” Dr. Jarvis agreed.
Dr. Lurie said areas with the highest survival rates are also incorporating automated devices to support resuscitation such as mechanical chest compression systems. “You can only get so far with a pair of hands,” he said. But these devices, along with intubation, should be employed later in the resuscitation process.
“Our teams are prohibited from using [mechanical compression] until after the first six minutes of CPR because there is some evidence that when it's used in those first ten minutes, the survival rate actually drops,” Dr. Jarvis said. “This may be because of a focus on attaching the device and not on high-quality early CPR. It's similar to intubation; our paramedics have to manually bag in the first ten minutes for any active oxygenation or ventilation. After ten minutes, then you're really in a different phase of cardiac arrest, and you're more likely to start suffering from provider fatigue in compressions. My gut says that when the quality of compressions starts to drop off, around that time point, is when you start to see benefits.”
Automated CPR devices are also essential for transport. “First, the quality of manual CPR is horrible in a moving ambulance,” Dr. Jarvis said. “Moreover, that's also how paramedics get killed.” Mechanical compression devices allow EMS providers to continue resuscitation for those patients who need it during transport, he said.
More widespread use of active compression CPR has also been coupled with two other interventions Dr. Lurie said he finds promising, though they remain a source of controversy because other EMS experts do not necessarily agree.
- Elevating the head and thorax during CPR. “Contrary to what you might think, doing this when doing device CPR has been found to double blood flow to the brain and heart after 15 minutes,” Dr. Lurie said. “We've seen improved outcomes in both pigs and humans. You need to prime the body with high-quality CPR first and use a device; you don't get enough forward flow to pump blood uphill with bare hands. But when you do that, the outcomes are pretty exciting.” Technology is now being developed to facilitate this intervention to allow it to be done at the right angle and right speed.
- ECMO for patients in refractory arrest who otherwise appear to be getting reasonable circulation based on their CO2 levels. “This ideally is best used in refractory v-fib, although other patients have been studied,” said Dr. Lurie, noting that such patients, when transported to an ED with ECMO—or, in France, when treated at the scene in an ECMO-equipped, physician-staffed ambulance—can be taken to the cardiac catheterization lab in more stable condition. “You can take a subset of patients previously left for dead, and about 45 percent of them walk out of the hospital.” (Resuscitation 2015;86:88; Resuscitation 2012;83:579.)
Meanwhile, the University of Minnesota is studying the feasibility of equipping ambulances that function as mobile emergency departments. “These first-of-their-kind super-ambulances would be capable of treating sudden cardiac arrest, stroke, and other extremely time-sensitive medical crises when they occur away from the hospital,” the university said in a press release.
Transport is one of the most debated topics in resuscitation—when to transport a patient in arrest—and was the prime focus of Dr. Mell and Dr. Weingart's “cage match” podcast. They agreed that successful resuscitation rates drop off a cliff after one or two shocks, but what should the focus be after that?
“I see patients who are not viable by most standards come to our ED ECMO program after 20 to 40 minutes of resuscitation in the field, and we are able to get ROSC,” Dr. Weingart said. “The earlier the better, of course; I'm not getting neurologically intact survival from ROSC at 50 minutes.”
The challenge of moving these patients with CPR in progress, Dr. Mell said, is that it almost requires you to know in advance which patients those responders are going to be. “For most folks, it'll be a 15-20-minute trip to someplace with ED ECMO. If I arrest on the ramp at the Mayo Clinic, then, yes, scoop me up and bring me into the hospital. But as the distances get more than a city block, you have the challenge of needing prognostication.”
“Why prognosticate?” Dr. Weingart countered. “Just do CPR, see if you have a shockable rhythm, and then get out of there. Why not transport every patient who's not in asystole and not prohibitively elderly?”
That begs the question of where to focus systemic resources. Most emergency physicians are practicing in hospitals that don't have ECMO in the ED or at a nearby facility. “In the near future, we will see a shift in how resuscitations are run at large tertiary academic centers versus community hospitals,” Dr. Jarvis said. “Besides access to ECMO, the other challenge—and the easier one to fix—is having cardiologists who are willing to take patients to the cath lab with ongoing CPR or once ECMO is going on. But that's not the reality for 90 percent of ED physicians right now. I think the easier problem to fix is the cath lab. Right now, they get penalized for peri-procedural deaths, and if they take someone who's already in arrest, there's a higher chance that they will die than someone with an N-STEMI who's talking. Things are bureaucratically stacked against them, and while that's a hurdle, it's easier to fix than putting ECMO in every ED in the country.”
More effort should be focused on improving each community's EMS system than on placing ECMO in every ED with a team trained in its use, Dr. Jarvis said. “Most people die in the field. They almost never go into arrest in the hospital,” he said. “In our community north of Austin, we aren't an academic center and we don't have ECMO. I have this huge reluctance to terminate CPR in the field on a patient in v-fib. When we work 20-30 minutes in the field, and then can't do anything else, if we transport to the ED we're basically taking the patient there to be called.”
Dr. Mell suggested that each hospital should have a “cardiac arrest champion” tasked with identifying what the institution can do. “If your hospital is not prepared to do much past the traditional methodology, then EMS should stay on the scene until the patient is gone,” Dr. Jarvis said. “Invest in community education, teaching paramedics how to deliver bad news and prepare people for grief, and work with your coroner on systems to deal with the body after unsuccessful resuscitation.”
Emergency departments should take the lead of EMS and look at resuscitation as a team sport that must be choreographed, Dr. Jarvis said. “The classic phrase—coined, not surprisingly, in North Carolina—is that we need to take a pit crew approach. Watch a NASCAR race and see how everyone in the pit crew knows exactly what to do and what steps to take as a well-functioning team. But in most cardiac arrests, unless your ED is specifically trained on this, everyone is doing their own thing.”
High-profile, potentially preventable deaths from cardiac arrest, like that of San Francisco Mayor Ed Lee, continue to make headlines. Mr. Lee died in December 2017 after suffering a heart attack while grocery shopping. “He might have died no matter what, but he didn't get the kind of care we are talking about, and that's unfortunately true for most Americans today unless you happen to have your cardiac arrest in a place like Palm Beach County, Florida, or Memphis, Tennessee, where they have adopted these state-of-the-art ideas and technology,” Dr. Lurie said. “And what they're doing is something other communities can do. Nobody's breaking the bank. They're using the Take Heart America bundle of care, getting people to the scene quickly, using high-quality CPR and advanced airway management, using ECMO and cooling at the hospital if the patient is still refractory, and having excellent results.” (Take Heart America: The 2017 Bundle of Care; http://bit.ly/2NJDtsV.)
Dr. Lurie said he is optimistic that these practices will spread over the next several years, with the release of the consensus resuscitation blueprint and more widespread use of lifesaving advances. “It doesn't cost a lot of money,” he said. “It takes leadership and willingness to embrace new ideas.”
If you're an avid emergency medicine social media user, you know that the Twittersphere was on fire with controversy about resuscitation recently. Howard Mell, MD, in his So What? 2.0 podcast on www.EM-News.com enlists the expertise of Jeffrey Jarvis, MD, to talk about what running a code is really like for most community emergency physicians. First listen to the EMCrit podcast by Scott Weingart, MD, that started the debate (http://bit.ly/2xzNqyl), and then tune in to hear what Drs. Mell and Jarvis have to say. (http://bit.ly/SoWhatHowieMell.)