Cardiocerebral resuscitation: the new cardiopulmonary resuscitation.

This article reviews research that shows that cardiopulmonary resuscitation (CPR) as it has been practiced and as it is presently taught and advocated is far from optimal. The International Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, hereafter referred to as “Guidelines 2000,” were evidence based.2 During their formulation, the greatest weight of evidence was given to placebo-controlled randomized trials in humans. Unfortunately, it is extremely difficult not only to obtain informed consent but also to obtain funding for studies of the magnitude necessary to answer critically important CPR questions. It is unfortunate that controlled CPR research in animals was given the lowest priority in the evidence-based scheme.2 In our opinion, controlled animal experiments provide data that may be nearly impossible to obtain in human trials in which the circumstance, age, disease states, interventions, and response times to arrest are variable and often unknown. On the other hand, the use of swine for CPR research is not the perfect experimental solution, because they are easier to resuscitate in that they have no underlying heart disease (unless experimentally produced), they are younger, and they have more compliant chests than older adults with cardiac arrest. Since the formulation of “Guidelines 2000,” old and new research in animals and new research in humans have rendered them outdated. Although they will be revised, it is unknown when and what changes will be made. Nevertheless, in 2003, the CPR research information from both animal and humans was so compelling that we could not in good conscience wait for yet another set of new guidelines. Accordingly, our CPR research group, in cooperation with the Tucson Fire Department, initiated a new comprehensive resuscitation program in November 2003 in Tucson, Ariz, with emphasis on these new research findings.3 We were encouraged in this effort by our colleagues in Europe,4 and, as noted below, recent studies in humans have reinforced our conclusions. Three Phases of Cardiac Arrest Due to Ventricular Fibrillation One of the many important concepts to come forward since “Guidelines 2000” were published is the 3-phase, timedependent concept of cardiac arrest due to ventricular fibrillation articulated by Weisfelt and Becker.5 The first phase is the electrical phase, which lasts 5 minutes. During this phase, the most important intervention is prompt defibrillation. This is why the benefit of the automatic external defibrillator (AED) has been shown in a wide variety of settings, including airplanes, airports, casinos, and in the community.6–10 The second phase of cardiac arrest due to ventricular fibrillation is the hemodynamic phase, which lasts for a variable period of time, but possibly from minute 5 to minute 15 of the arrest. During this time, generation of adequate cerebral and coronary perfusion pressure is critical to neurologically normal survival; however, if an AED is the first intervention applied during this phase, the subject is much less likely to survive for reasons that will be presented below. The third phase is the metabolic phase, for which innovative new concepts are needed, the most promising of which is the application of hypothermia. An appreciation of these 3 phases helps one put into context some of the recent findings in resuscitation research.