By Dr. Ken Lavelle, MD, NREMT-P
You are standing by at a fire in a strip mall. Rehab has gone well, and the weather conditions have cooperated — temperatures are cool. Suddenly you hear commotion from a nearby intersection where your fire police have been directing traffic. You hear several firefighters yelling, "Jack! Jack!" followed by, "Medic! Man Down!" Jack is a senior member, who has been with the department for over 50 years. He still makes every meeting and fundraiser, and hasn't missed a fire in years, most recently with the fire police. You see Jack lying in the street as you grab your equipment. Bystanders report no trauma — he just collapsed to the ground. When you get to his side, he is unconscious and unresponsive, and you can feel no pulse — cardiac arrest.
What can you do to maximize Jack's chances of surviving?
Before you answer, we must put the emergency medical care of sudden cardiac death in context. From the start of CPR in the 1950s and 1960s, through the development of defibrillation and Advanced Cardiac Life Support, the survival rate from out-of-hospital cardiac arrest (OOHCA) has been dismal and generally unchanging. Some communities such as Seattle have better rates of survival, presumably from very aggressive public CPR campaigns. But despite the advances in overall medical care, we don't seem to be doing any better with cardiac arrest in the past 40 years. Why?
Usually when this happens, it means that a fundamental concept of the care model is flawed. Recent research indicates this is the case. It was always thought that a patient in cardiac arrest needed not only chest compressions, but also oxygenation and ventilation. During a cardiac arrest, it is not uncommon for an EMS provider to provide bag valve mask (BVM) rates that exceed 30 per minute. "How can it hurt?" was the thought. We now know that the chest compressions are more critical than ever imagined, and they should be emphasized over almost all other treatment.
Ventilations are one action that interrupt chest compressions and decrease the resultant blood flow. Another action decreases the quality of chest compressions — patient transportation. We often would rush to get the patient in the ambulance and then race to the hospital. During this trip the quality of compressions is worse than if the patient is lying still. I can tell you that there is very little we can do in the emergency department that a good BLS and ALS crew can't do in the field. (And there is not very much ALS can offer to improve survival as long as there is good, quality BLS being performed.)
This is a significant paradigm shift. We are used to change in medicine, but EMS has always been reluctant to grasp how quickly medicine can change. Every week the way we treat patients changes based on research, studies and sometimes just discussion.
But let's get back to Jack. We can give him the best chance of survival by doing good, quality CPR right there in the street. Compressions should be stopped for no more than five seconds for any reason. The ideal rate is believed (for now) to be 100 per minute. This cadence can be obtained by humming to oneself the song 'Staying Alive' by the Bee Gees. ('Another One Bites the Dust' by Queen also works, but bystanders may get the wrong idea if they hear you.) Change the provider doing chest compressions every two minutes. The machismo has to go — it has been proved that the quality of compressions decreases after two to three minutes regardless of how big and strong you think you are so rotate out.
Ventilations can be initiated after the placement of an oral airway. A BVM is fine, or an alternative airway such as the CombiTube or King LT can be placed. Intubation has taken a back seat primarily due to the time necessary to place the endotracheal tube. The current American Heart Association recommendations are for a 30 to 2 ratio but I would not be surprised to see even fewer ventilations in the future or even no ventilations for the first several minutes of a code.
When to defibrillate is currently being debated. It is believed that if a victim has been in cardiac arrest for several minutes, that doing several minutes of CPR prior to the first defibrillation may help provide more oxygen to the heart and clear some acidosis from the blood, thus increasing the chance that the heart will start beating after a defibrillation attempt. However, our patient may have been down for only seconds so an immediate defibrillation is indicated. After the shock, get right back on the chest with compressions — don't waste time with a pulse check. It is highly unlikely that the heart will immediately be able to start moving blood so quickly. Do a 2 minute round of CPR and then check the pulse.
Don't be in a rush to move Jack — the best chance he has is to receive quality EMS right there on scene. Follow ACLS guidelines and of course always follow local protocol, but remember — BLS over ALS.
One last comment. Many of us in emergency services are able to "acquire" a CPR card without having to take a real course. However the concepts of CPR are changing so fast right now that obtaining a card in this manner short-changes ourselves and our patients. One day, our patient may be a friend like Jack. Doesn't he deserve the best care we can provide, and not concepts from 15 years ago? Ask your training officer or medical director to provide a "resuscitation update" or advanced CPR class on these concepts so you can learn what you need to learn.