Most people who appreciate high forms of achievement, regardless of their field, quickly recognize Englishman Roger Bannister as the first runner to break through the barrier of the four-minute mile. When Sir Roger was clocked at three minutes and 59.4 seconds at Oxford, his performance wasn't just remarkable; it was the result of a precisely executed plan made possible by his scientific study and refinement of the methods and mechanics of running. In contrast, very few recognize the name of Gunder H gg, the Swedish runner who held the nine-year world record of four minutes and 1.3 seconds until that fateful day in May 1954.(1) Both gentlemen are worthy of our adulation as a new performance record rarely occurs without significant stimulation from the prior one. What does a timed run in 1954 have to do with your next STEMI patient? A lot, if you want to provide them the best care.
The STEMI Care Race Paradigm & the D2B 90-Minute Stopwatch
Many champions of timely ST-elevation myocardial infarction (STEMI) care have used the relay race analogy with EMS carrying the patient out of the blocks, rapidly transferring care to our emergency department (ED) colleagues, and finishing with their hand-off to an interventional cardiologist and the cardiac catheterization lab team for the anchor leg of emergent percutaneous coronary intervention (PCI). Not many night holiday weekend shifts ago, the time goal for completing just the emergency medicine care and subsequent interventional cardiology event of balloon angioplasty was no more than 90 minutes after the patient's arrival at the hospital door, thus the creation of "Door-to-Balloon" or D2B time. As recently as with the Nov. 30, 2006 publication of the New England Journal of Medicine, only a minority of hospitals treating STEMI patients with emergent PCI routinely beat the 90-minute D2B clock. Fortunately, this same publication provided significant stimulus to improving D2B times through a study titled "Strategies for Reducing the Door-to-Balloon Time in Acute Myocardial Infarction."(2)
If you have not already read and placed a copy of this study in your EMS resource file, make it a priority. This single article may prove very helpful in justifying the costs of your STEMI recognition training, monitor/defibrillators and ECG transmission. Of the six strategies significantly associated with faster D2B times, enabling the ED to activate the cardiac catheterization lab while the patient was still in EMS care yielded a typical savings of 15.4 D2B minutes. Thom Dick would likely say it best this way, "That's a lot of cardiac muscle you saved, Life-Saver!" In fact, more time was typically saved in STEMI care utilizing EMS 12-lead acquisition and analysis prior to the patient's arrival at the hospital than having an attending cardiologist inside the hospital 24/7. That's a potent fact to point out when your cardiac care budget is getting the evil eye, isn't it?
Not to make too much of one study, but this one does represent a real step forward in the acknowledgement and appreciation that cardiologists have toward EMS and its dedicated professionals. The widespread failure to meet the D2B goal of 90 minutes and the relatively simple and straightforward steps to success were equally compelling. If the 90-minute mark was going to be routinely met and hopefully routinely shattered, cardiologists agreed that often EMS was going to make the critical difference. So, how far have we come in the last three years? Probably more exciting, where are we going?
The D2B, E2B & C2B 60-Minute Stopwatches
As more and more emergent PCI-capable hospitals have implemented these strategies, D2B times of 90 minutes or less are becoming commonplace. Dr. Marc Eckstein, medical director of the Los Angeles City Fire Department, and colleagues published an affirming study of the value that comes with regionalizing STEMI care. In the Los Angeles area, EMS clearly makes a critical difference in D2B performance.(3) The Los Angeles experience is just one example of how emergency cardiac care (ECC) systems have collectively put up some impressive times far less than the previously thought "four-minute plus mile" to the cardiac catheterization lab. If you've been active in STEMI care over these past three years, you can firsthand attest to how much emphasis is being put on shortening D2B times. Many leading emergent PCI-capable hospitals have self-initiated the "60-Minute D2B" goal. One of the best practices in sharing these faster times with EMTs and paramedics is to let them see the whole STEMI clock in real time. Although it may not be possible in the busiest of EMS systems or even routinely possible in any EMS system, each time that EMTs and paramedics can accompany their patient and watch exacting yet rapid angioplasty in the cath lab yields confirmation that no phone call, letter or certificate can surpass.
Back to Sir Roger's achievement that, after all, was no accident but a carefully orchestrated event. Why can't we take similar inspiration from Gunder H gg (our D2B record holder, if you will)? While we're at it, let's fire the starting gun a little more accurately. If you yourself were having a STEMI, when would you consider your care to start? You'd probably agree passing through the doors into the ED is a necessary event along the way, but it certainly doesn't constitute the beginning of your race for survival. Thus, the "EMS Care to Balloon" interval, or E2B, better reflects the race you're suiting up to run with your STEMI patients this shift. Fortunately, more ECC systems are speaking in terms of E2B and still keeping their goals at an impressive 60 minutes.
But wait, there's more! And we're not referring to a second set of knives. Doesn't our care of the STEMI patient really start with the 9-1-1 call? Emergency medical dispatchers can effect significant influence on care even before EMTs and paramedics arrive at the patient through call prioritization, phone-initiating CPR (when applicable), prompting AED retrieval (when applicable), and aspirin administration. Thus, we should be using "9-1-1 Call-to-Balloon" or C2B times when best measuring how fast our ECC systems are performing. Obviously, not all STEMI patients seen at any particular PCI-capable hospital will arrive via EMS, but that's a whole other issue of public education of which we're well aware. Still, most emergent PCI-capable hospitals do see a significant portion of STEMI patients' post-EMS care and should be motivated to consider this newest stopwatch continuing to be set at 60 minutes or less. Adopting the C2B standard pulls in all key participants in the STEMI patient's acute care -- from EMD through interventional cardiologist. Serendipities of such a workgroup are bound to occur.
Achieving C2B in 60 Minutes or Less
If you've historically viewed the STEMI relay race in three sequential 20 to 30 minute segments allocated to EMS scene care and transport, the ED, and the cardiac cath lab respectively, achieving C2B in less than 60 minutes requires routinely breaking away from this paradigm. It's rarely practical that EMS can process a 9-1-1 call, respond, deliver on-scene care, notify the appropriate emergent PCI-capable hospital-based partner(s), and transport the patient safely within 15 to 20 minutes in all but the smallest of jurisdictions. So, what's an aggressive, enlightened ECC system to do? Take a segment largely out of the time equation as often as possible -- that segment is the ED. Heresy, o' emergency physician colleagues? No, rather a celebration of what our colleagues in the field have accomplished in not just adopting 12-lead ECG technology, but in many instances reaching laudable analysis skills with our mentoring and empowerment.
Then how does your ECC system actually put this philosophy into the mechanics of reliable performance? Through adopting a series of best practices, which may include the following:
12-lead ECG analysis training for paramedics.The proprietary analysis software in your choice of monitor/defibrillator is increasingly accurate, but we can rest assured it will not replace the discerning eye of a trained paramedic able to make what a machine cannot do -- a clinical correlation. Well trained paramedics are capable of not only raising the flag on marginal 12-lead ECG abnormalities, but also just as capable of avoiding unnecessary cath lab activations for STEMI mimics.
12-lead acquisition and transmission training for EMTs.Although analyzing a 12-lead ECG will likely remain within the paramedic scope of practice for at least the short-term future, obtaining and sending a 12-lead ECG should clearly be recognized as an EMT-Basic skill. In Oklahoma City and Tulsa, EMTs in our first response agencies as well as our transport agency take a lead role in 12-lead ECG handling. This typically results in a 12-lead ECG being acquired contemporaneously with the paramedic's initial assessment and focused history-taking of the patient. As soon as one of the treating paramedics has over-read the 12-lead ECG it is sent to the destination hospital. If you re waiting to acquire the 12-lead ECG until your patient is "in the box," you're losing time that cannot be regained.
Ensure reliable 12-lead ECG transmission by routinely test transmitting.What does "routinely" mean? Daily. In Oklahoma City and Tulsa, our EMSA Materials Management Associates verify successful transmission capability from all front-line monitor/defibrillators at least once every 24 hours. With our system status management deployment of ambulances, units must be cleaned, restocked and readied at shift changes within minutes at a central location, favoring a small cadre of equipment professionals performing this quality assurance function. In static deployed systems, station-based EMTs and paramedics can make 12-lead ECG test transmission a key event at shift change. For instance, the Plano (Texas) Fire Department has been performing a daily 12-lead ECG test transmission from each front-line monitor/defibrillator to its base station hospital receiving station for the past few years. The bottom line is that frequent test transmissions ensure that knowledge and/or technical failures of transmission procedures are rapidly identified and corrected, minimizing the chance that your STEMI patient's 12-lead ECG won't be received by the emergency physician and/or cardiologist at the destination hospital.
Activation of the cardiac catheterization lab from the field.The "activation lever" may be pulled directly by the paramedic or indirectly through an over-read by the emergency physician, depending upon your system protocols and your local standards of care. Master Eagles member Dr. Ray Fowler (Dallas/BioTel) and Dr. Corey Slovis (Nashville) delivered a stirring debate as to the merits and difficulties of direct versus indirect activation at this past February's EMS State of the Science - A Gathering of Eagles XI conference held in Dallas.(4) One of the most recent published studies on paramedic accuracy of 12-lead ECG interpretation indicates that paramedics can recognize STEMI and activate the cardiac catheterization lab appropriately with 88% accuracy.(5) Regardless of which method is employed, the key is early activation of the cath lab prior to patient arrival. Today's generation of 12-lead ECG transmission platforms and receiving devices will allow simultaneous notification of the ED physician and charge nurse, the cardiac catheterization lab team, and the interventional cardiologist. When you're utilizing each of the prior best practices, the interventional cardiologist may literally have their wheels turning prior to yours!
Direct transfer of the patient from the ambulance to the cath lab.Increasingly common in high-performance ECC systems, it truly is the only way you can routinely achieve C2B times in less than 60 minutes (and inspiringly, less than 30 minutes!). We're fortunate to have similarly committed emergency physicians and cardiologists in Oklahoma City and Tulsa achieving these kinds of times. It's not about bragging rights or "market share" dynamics; it's a race for physiologic salvage of infarcting cardiac muscle. And it's not just in the heartland of America. From Los Angeles to Houston to Miami to Boston to Minneapolis, these are just a few of today's large, urban systems committed to improving upon already enviable STEMI care performance. Even in direct transfer systems, the ED continues to play an integral role as a number of STEMI patients may still arrive prior to the cardiology team being immediately available or when the STEMI patient has pressing airway control needs.
Be on the lookout for a best practices document related to 12-lead ECGs in EMS from an Eagles writing group led by Louisville EMS Director and Medical Director Dr. Neal Richmond and likely slated for publication in early 2010. Additional consensus commentary on some of these best practices and other related procedures can be reviewed in an excellent resource document from the American Heart Association's Interdisciplinary Council on Quality of Care and Outcomes Research, Emergency Cardiovascular Care Committee, Council on Cardiovascular Nursing, and Council on Clinical Cardiology.(4) After your reading, it will prove another keeper for your EMS resource document file.
Timeliness of STEMI care continues to evolve with exciting new performance standards promulgated within the EMS, emergency medicine, and interventional cardiology practices of medicine. EMS is critically positioned to make a measureable difference in the morbidity and mortality of STEMI through best practices related to 12-lead ECG acquisition, analysis and transmission. Key leaders in local ECC systems should continue to progress from the still recently adopted 90-minute D2B stopwatch to the ambitiously calibrated 60-minute (or less) C2B goals for STEMI patients. Less than a quarter of a generation's lifetime ago, we justifiably had pride in performing 3-lead ECGs, administering oxygen, nitroglycerin, aspirin, maybe morphine, and transporting subsequently diagnosed STEMI patients to the closest hospital. Among the great advances in the EMS practice of medicine, accurate EMS diagnosis of STEMI and selective transportation to rapidly performing emergent PCI capable hospitals stands as an achievement with particularly substantial impact upon patient survival and quality of life.) It's an exciting time for EMS in emergency cardiac care -- isn't it inspiring to think about what performance capabilities will arise next?
Jeffrey M. Goodloe, MD, NREMT-P, FACEP,is associate professor and director of the EMS Division of the Department of Emergency Medicine, The University of Oklahoma School of Community Medicine in Tulsa. He has the great privilege of serving as medical director for all Medical Control Board affiliated EMS agencies in metropolitan Oklahoma City and Tulsa, including the Emergency Medical Services Authority (EMSA), the Oklahoma City Fire Department, and the Tulsa Fire Department. More accurately, he is an EMT-Basic who started a career in EMS in 1988 and never quits learning. All the above considered, Leo, his beloved greyhound, is just happy that he remains employed to keep dog food in the dish. He can be contacted email@example.com.
Learn more from Dr. Jeffrey M. Goodloe at theEMS Today Conference & Expo,March 2 6 in Baltimore.
1. Bannister, R: The Four-Minute Mile. The Lyons Press: New York. 1955.
2. Bradley EH, Herrin J, Wang Y, et al: "Strategies for reducing the door-to-balloon time in acute myocardial infarction." New England Journal of Medicine. 355(22):2308-2320, 2006.
3. Eckstein M, Koenig W, Kaji A, et al. "Implementation of specialty centers for patients with ST-segment elevation myocardial infarction." Prehospital Emergency Care. 13(2): 215-222, 2009.
4. Fowler RL & Slovis CM: "No one's jammin' their transmission! Fowler and Slovis take the gloves off and debate sending in 12 leads." Debate Presentation at EMS State of the Science -- A Gathering of Eagles XI. Feb. 21, 2009. Dallas.
5. Trivedi K, Schuur JD, Cone DC: "Can paramedics read ST-segment elevation myocardial infarction on prehospital 12-lead electrocardiograms?" Prehospital Emergency Care. 13(2):207-214, 2009.
6. Ting HH, Krumholz HM, Bradley EH, et al: "Implementation and integration of prehospital ECGs into systems of care for acute coronary syndrome: A scientific statement from the American Heart Association Interdisciplinary Council on Quality of Care and Outcomes Research, Emergency Cardiovascular Care Committee, Council on Cardiovascular Nursing, and Council on Clinical Cardiology." Circulation. 118(1);1066-1079, 2008.