New or old to EMS, if you’re reading this article anywhere close to the summer of 2012, you’re a part of the latest renaissance in the EMS attack on unexpected cardiac arrest. We’re collectively learning things we didn’t fully appreciate before (e.g., the pathophysiology of cardiac arrest and post-cardiac arrest) and things we appreciated too much (e.g., hyperventilation for oxygenation and frequent pauses in chest compressions for cardiac rhythm determination–not to mention sequential defibrillations). We’re also learning more things we can do to promote meaningful survival (e.g., continuous chest compressions and therapeutic hypothermia)–all at rates faster than you can finish reading this article. Good thing we’re all in this together. We need everyone’s energy and interest to succeed in this team practice of EMS medicine. We’ll talk more about success later, but some of you are undoubtedly moaning just a little bit. We can hear some of you newer colleagues saying, “Not another feature article on cardiac arrest. “¦ What’s the deal?” Let’s address “cardiac arrest fatigue” up front, because the information that follows is too important to your patients for you to miss it or gloss over it.
Evolution of Cardiac Arrest
The “deal” is that we owe the unfortunate existence of unexpected out-of-hospital cardiac arrest quite a lot. This single clinical entity is a cornerstone for existence of modern day EMS. Without EMS, who else in a community would effectively respond to and address cardiac arrest? Our predecessors may have been at the mercy of the 1960’s science (just like we’re at the mercy of the 2010’s), but they sure did wonders with it. We’re pretty sure we wouldn’t have been as successful in resuscitating many of those cardiac arrest victims as our earlier colleagues were with unbridled ambition and hope using some interesting practices in artificial ventilation and compressions. In fact, come to think of it, even in the late 1980s and early 1990s as a paramedic, Dr. Goodloe didn’t “¦ but we promise he was following the protocols his medical director gave him.
If you knew Johnny and Roy back in the days of Emergency! (or maybe even know of them at all), you also remember the years without such a renaissance of EMS cardiac arrest care. These were dangerous years for all involved, and if not for a nidus of restless, persistent leaders and researchers, we wouldn’t be talking about cardiocerebral resuscitation, continuous chest compressions, controlled oxygenation/ventilation and hypothermic benefits.
Even partial incorporation of these ideas will save more lives, but don’t fall victim to accepting “very good” as the destination. Take the journey of relentlessly pursuing “excellence,” and you’ll more than likely start enjoying visits with patients who were recently dead, only to be unquestionably alive and as neurologically intact as ever. As exciting as the recent past has been, the future looks even better if we’re simply stubborn and bold enough to capitalize on what we currently know.
Like you, we have the privilege of working daily with some particularly inspiring colleagues–about 3,300 of them in fact. These EMS professionals in metropolitan Oklahoma City and Tulsa have long been known for admirable cardiac arrest care that yielded “very good” survival (discharge-to-home survival) rates hovering around 30% of those patients who had a witnessed collapse, received some form of bystander CPR and were found in a shockable rhythm on first EMS contact. Making interval improvements during the past three years, this team has nearly reached 40% success in those same patients. That’s a testament to hard work done well and with enthusiasm. What’s a medical oversight team to do but enjoy being a part of such success? A lot.
It’s fairly easy to know what you know you don’t know, but how do you know what you don’t know you don’t know? (Challenge coin to the reader who can quickly say that 10 times in a row.) In the spring of 2011, our entire medical oversight team went to spend time with our friends, new and old, at Seattle Medic One. As our medical director, Goodloe was smart enough to know he wasn’t smart enough to already know the answers to achieve 50%-plus success from witnessed, bystander-CPR supported, out-of-hospital ventricular fibrillation (v fib) arrests. So he took a big blank book and a camera. On the way back home from Seattle, the answer really was as simple as putting these pieces together:
>> Push continuous chest compressions to new levels. Seattle Medic One showed us station-level training, highlighting doing compressions while the AED was charging. Note: not while discharging/delivering shock. Kansas City, Mo., and many Arizona systems have reported on the benefits of passive oxygenation–benefits easily appreciated if the initial resuscitation team comprises only two EMS professionals.
- >> Move from 100 compressions per minute to 120 compressions per minute. This is based on Resuscitation Outcome Consortium (ROC) study data (see further discussion below), and this compression rate goes hand in hand with instituting system-wide use of compression metronomes.
- >> Build on the concept of tightly defined resuscitation roles for all levels of EMS professionals. Credit is due to a lot of systems but directly to Austin/Travis County, Texas, and their “CPR triangle” model.
- >> Incorporate hands-on, station-level training taught directly by medical oversight officers and the medical director (e.g., Seattle Medic One).
- >> Stay the course with the impedance threshold device. This idea is supported in post-hoc analysis of the ROC PRIMED data by ROC investigators and their EMS systems, which are too numerous to mention.
- >> Get more aggressive in initiating post-arrest therapeutic hypothermia (e.g., Wake County (N.C.) EMS and other innovative systems).
It sure is great to have smart friends and colleagues. So here’s what we’re doing.
The EMS system for Metropolitan Oklahoma City and Tulsa has done a comprehensive restructuring of our cardiac arrest program in a three-part approach: chest compression fundamentals, resuscitation team dynamics and accelerating feedback on resuscitation performance. We’re pushing to be the largest system in the U.S. (maybe anywhere) with 50%-plus survival from witnessed, bystander-CPR supported, out-of-hospital v fib arrests. It’s a bold goal, but an important one. It’s not a contest with other EMS systems. This is solely a contest with unexpected, undesired cardiac arrest. Our patients will win it, and so can yours.
Step one was to focus on chest compression fundamentals. Over a four-month period in the fall of 2011, a sizeable portion of nearly every weekday was spent in the fire stations and ambulance classrooms doing individual, hands-on-the-manikin training. The medical oversight team (this article’s authors) taught nearly 3,300 EMS professionals what we all sometimes take for granted: good fundamentals of chest compressions. Don’t ever overlook the fundamentals.
If you’re a college basketball fan, you may be aware that legendary coach John Wooden spent part of the first day in training camp showing his players how to put socks on correctly. What? His principle was that you can’t play good basketball if you have blisters on your feet. Correct sock mechanics and proper shoes prevent blisters.
If proper sock mechanics are that important to an unparalleled success on the collegiate basketball court, how important are proper chest compression mechanics to continuing life? We used recording manikins that gave real-time feedback for proper placement on the sternum, proper depth of compression and proper complete recoil of the chest between compressions.
Before we did the “official” recording, we wanted everyone to do a solid minute trying to achieve a rate of 120 compressions per minute. You might think it would be hard to speed up an ingrained rate closer to 100 compressions per minute; however, we found a typical compression rate of 130—140 per minute. Metronomes were definitely needed, but to slow our resuscitators. Enthusiasm is a great thing, but the ventricle needs enough time to fill for the next compression to be effective. So why 120 compressions per minute? At the 2011 EMS State of the Science/A Gathering of Eagles Conference, Goodloe was fortunate to learn emerging concepts from Ahamed Idris, MD, a key leader in EMS research and professor in the Division of Emergency Medicine at the University of Texas Southwestern Medical Center at Dallas.
Idris relayed that ROC investigators were increasingly convinced that compression rates were linked to return of spontaneous circulation (ROSC), and the peak success wasn’t at 100 compressions per minute. His recent study in Circulation explains that rates very near 120 compressions per minute produced more ROSC but not sustained survival. Although transient ROSC isn’t the goal, ROSC is a fundamental event for neurological recovery. We encourage you to read the work of Idris and his ROC co-investigators. For now, we believe we’re on the right track and are staying at 120 compressions per minute.
With a metronome at 120 compressions per minute, each EMS professional in our system did another minute to reinforce the right mechanics. Each front-line apparatus in our system has a metronome defaulted to 120 tones per minute. Most crews carry the metronome attached to their monitor/defibrillator or automated external defibrillator. Post-resuscitation analysis shows us excellent compliance with using the metronomes because compression rates are consistently at, or extremely near, 120 per minute. There’s good science to support the use of metronomes if consistency in rate of compressions is part of your goal. Building on these fundamentals, we set to refine the dynamics of the resuscitation team, part two of the trilogy in the fight against cardiac arrest.
Look for the Oklahoma City and Tulsa Resuscitation Team Playbook in JEMS September 2012 and learn about the improved feedback EMS professionals in Oklahoma City and Tulsa are receiving to further calibrate their life-saving skills. JEMS
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