Review of: Ewy GA, Kern KB: "Recent advances in cardiopulmonary resuscitation: cardiocerebral resuscitation." Journal of the American College of Cardiology. 13;53(2):149-57, 2009.
This article is an extensive review and discussion of the science that has led to the chest compression-only CPR technique used in the study 2008 Annals of Emergency Medicine study, "Cardiocerebral Resuscitation Improves Neurologically Intact Survival of Patients with Out-of-Hospital Cardiac Arrest."(1) In that study, the authors modified the 2000 American Heart Association (AHA) guidelines for witness V-fib/V-tach (VF/VT) arrests. They reported that their protocol improved neurologically intact survival from witnessed VF/VT arrest from 15 to 39%.
In the 2009 article, Dr. Ewy provides a more detailed discussion of the science and potential implications of expanding what had become termed cardiocerebral resuscitation (CCR) beyond that of EMS to include recommendations for bystanders and post-resuscitation care.
Dr. Ewy provides evidence to support the elimination of "rescue breathing" by laypersons, because it delays the institution of chest compressions. He further discusses how endotracheal intubations interrupts chest compressions and may contribute to hyperventilation, which research has shown diminishes blood return to the heart. Dr. Ewy concludes the paper with an extensive review of the literature supporting post-resuscitation management, including hypothermia and the role of cardiac arrest resuscitation centers, with interventional catheterization capability.
Drs. Ewy, Bobrow, Kellum are among the many who are pushing the envelope of our understanding of cardiac-arrest management. While we're bringing patients back to life and obtaining a perfusing pulse upon arrival to the emergency department (ED), our ultimate goal is to discharge patients alive AND neurologically intact. This has led to the concept of cardiocerebral resuscitation with the goal of integrating techniques that get the heart to beat and minimize the ischemic insult on the brain.
For most of us, the AHA guidelines are the "Law of the Land" -- considered the standard of care. However, even the AHA recognizes that this is not the case. So how do we integrate the concepts Dr. Ewy and his colleagues profess into our practice? Or, do we even consider it now since the 2010 AHA guidelines are just a matter of months away from publication?
First, we must recognize that these CCR studies have dealt only with witnessed arrests in VF/VT. What do we do with unwitnessed arrests and asystole/ pulseless electrical activity (PEA)? Dr. Ewy believes strongly in the three-phase model of cardiac arrest, which suggests the metabolic abnormalities are mounting after 10 minutes and may benefit from more aggressive pharmacologic therapy.
Although I agree with the science that early intubation interrupts CPR, Dr. Ewy doesn't take into consideration the growing use of non-visualized airways, such as the King LT. Once placed the ResQPOD, an impedance threshold device, has shown conclusively to increase blood return to the heart and improve cardiac-arrest survival, particularly in asystole and PEA.
I'm in total agreement with the author on the need to move these patients to cardiac-arrests centers for hypothermia and angiography. However, the author hasn't addressed the issue of automated CPR devices in the event return of spontaneous circulation is not obtained in the field. For BLS services without access to ALS resources, to provide the pharmacologic agents necessary to promote survival perhaps a one-size-fits-all approach is simply not the answer.
That being said, I encourage everyone to get your hands on a copy of this article, because it will provide you with insight into the process driving the fundamental science of cardiac-arrest care.
1. Kellum MJ, Kennedy KW, Barney R:"Cardiocerebral resuscitation improves neurologically intact survival of patients with out-of-hospital cardiac arrest." Annals of Emergency Medicine. 52(3):244-52, 2009.