Since the introduction of cardiopulmonary resuscitation (CPR), we have been forced to rethink our definitions of life and death. Although sporadic accounts of attempted resuscitations are recorded from antiquity [1, 2 and 3], until recently no rational quarrel could be found with the sixth century BC poetic fragment of Ibycus, “You cannot find a medicine for life once a man is dead” [4]. Until 1960, successful resuscitation was largely limited to artificial ventilation for persons who had undergone respiratory arrest due to such causes as near-drowning, smoke inhalation, and aspiration. Such attempts were likely to succeed if performed before cardiac arrest had resulted from hypoxia and acidosis. Emergency thoracotomy with “open heart massage” was rarely resorted to and was occasionally successful if definitive therapy was readily available [5]. Electrical reversal of ventricular fibrillation (VF) by externally applied electrodes was described in 1956 by Zoll et al. [6]. This ability to reverse a fatal arrhythmia without opening the chest challenged the medical community to develop a method of sustaining adequate ventilation and circulation long enough to bring the electrical defibrillator to the patient’s aid. By 1958, adequate rescue ventilation became possible with the development of the mouth-to-mouth technique described by Safar et al. [7, 8] and Elam et al. [9]. In 1960, Kouwenhoven et al. [10] described “closed chest cardiac massage,” thus introducing the modern era of CPR. The simplicity of this technique—“all that is needed are two hands”—has led to its widespread dissemination. The interaction of this technique of sternal compression with mouth-to-mouth ventilation was developed as basic CPR. The first national conference on CPR was sponsored by the National Academy of Sciences in 1966 [11]. Instruction in CPR for both professionals and the public soon followed through community programs in basic life support (BLS) and advanced cardiac life support (ACLS). Standards for both BLS and ACLS were set in 1973 [12] and were updated in 1979 [13], 1985 [14], 1992 [15], 2000 [16], and 2005 [17].

For some individuals with adequately preserved cardiopulmonary and neurologic systems, the cessation of breathing and cardiac contraction may be reversed if CPR and definitive care are quickly available. If other systems are also spared, prolonged and vigorous life may ensue. The short period during which the loss of vital signs may be reversed is often referred to as clinical death. For clinical death to be reversed, however, ventilation and circulation must be restored before irreversible damage to vital structures occurs. The state of irreversible death is referred to as biologic death. In difficult circumstances, the best single criterion (medical and legal) for the ultimate death of the functioning integrated human individual (i.e., the person) is brain death [18, 19, 20, 21, 22 and 23]. By this criterion, we can make decisions as to the appropriateness of continuing “life-sustaining” techniques.

The value of standardized CPR continues to undergo considerable scrutiny. Unfortunately, it appears that its efficacy is limited. CPR does not seem to go beyond short-term sustaining of viability until definitive therapy can be administered. This was the stated goal of Kouwenhoven et al. [10]. The benefit of rapid initiation of CPR has been demonstrated in numerous studies [24, 25, 26, 27, 28 and 29]. Data from prehospital care systems in Seattle showed that 43% of patients found in VF were discharged from the hospital if CPR (i.e., BLS) was applied within 4 minutes and defibrillation (i.e., ACLS) within 8 minutes. If either was delayed, survival rates were much lower. Survival rates for patients in asystole or with pulseless electrical activity (PEA) were much lower [30, 31, 32 and 33]. In a Miami study, none of the patients found in bra- dyarrhythmia or asystole survived, whereas 23% of those in VF were eventually discharged [34, 35]. Perhaps one of the benefits of the early initiation of CPR is the prolongation of VF, which increases the likelihood that ACLS with attempts at defibrillation will be successful. If the onset of CPR is delayed, or if the time to defibrillation is longer than 10 minutes, the probability is greater that the patient will be in asystole or in fine VF and will convert to asystole.

Even though patients experiencing cardiac arrest in the hospital can be expected to receive CPR and definitive therapy well within the 4- and 8-minute time frames, older studies determined that their chances of being discharged alive were generally worse than for out-of-hospital patients. This was thought to be due to serious underlying medical problems [36, 37, 38, 39 and 40]. A more recent study suggests that when in-hospital cardiac arrests due to VF or ventricular tachycardia (VT) are witnessed and defibrillation is conducted rapidly, survival to discharge is excellent [41].

In 1967, Pantridge and Geddes [42] introduced the mobile intensive care unit (ICU) in Belfast, Ireland. Since then, emergency medical transport programs have spread throughout the world. In recent decades, there has been a move to further approximate the mobile ICU of Pantridge and Geddes by adding the capability of defibrillation to the emergency medical service system [43, 44, 45 and 46]. This is already in place in most metropolitan areas. Recognizing the importance of early defibrillation, it is
imperative that all first-response systems provide this necessary service, either by using emergency medical technicians capable of performing defibrillation or by equipping and training emergency personnel with automatic or semiautomatic defibrillators [47, 48, 49 and 50]. The development of inexpensive, small, lightweight, easy-to-use, voice-prompted defibrillators would allow early access to defibrillation, before the arrival of emergency medical services (EMS) [51, 52]. Where these have been made available, and where first-responders have been trained in their use, survival rates have been dramatically improved [53, 54 and 55].

Although the current approach is modestly successful for VF, CPR techniques have most likely not yet been optimized, and further improvement is greatly needed [56]. Cardiac output has been measured at no better than 25% of normal during conventional CPR in humans [57 58, 59 and 60]. In animal models, myocardial perfusion and coronary flow have been measured at 1% to 5% of normal [61, 62 and 63]. Cerebral blood flow has been estimated to be 3% to 15% of normal when CPR is begun immediately [64, 65 and 66], but it decreases progressively as CPR continues [67, 68] and intracranial pressures rise [69, 70]. Despite these pessimistic findings, complete neurologic recovery has been reported in humans even after prolonged administration of CPR [71].

Researchers continue to evaluate new approaches and techniques, and further refinements in the delivery of CPR can be expected. Although research in this area must be enthusiastically encouraged, assiduous attention to research methods and their applicability to humans is required to prevent an overly hasty and potentially injurious change in the current guidelines. The wide variety of experimental methods and models makes evaluation of apparently contradictory research results difficult. Animal preparations for research in resuscitative techniques have limited application to humans, largely because of differences in size and configuration of the thoracic cage. Before new basic CPR techniques can be endorsed with any confidence, they must have been demonstrated to improve either survival or neurologic outcome. In addition, they must be simple to apply in an arrest and, optimally, they should be simple to teach and applicable by one rescuer without undue effort.

Any significant improvement in CPR technique would seem to require an understanding of the mechanism by which blood flows during CPR. However, there is no unanimity among researchers in this area. It is of interest that significant advances seem to have been made by research groups holding very different ideas concerning the basic mechanism of blood flow during CPR. Indeed, it is possible that several mechanisms are operative; which of these is most important may vary according to a patient’s size and chest configuration.

Several experimental and alternate techniques of CPR are presented in Table 22-1 [64, 66, 74, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105 and 106].

The fear provoked by the spread of human immunodeficiency virus (HIV) may lead to excessive caution when dealing with strangers; it has clearly decreased the willingness of both the lay public and health professionals to learn and perform CPR. The effect of this fear on CPR is serious and must be addressed at some length [131].

The public’s fear can be counteracted only by continued education and by stressing the facts. Health care workers have more opportunities for exposure to patients with HIV and their concerns must be adequately addressed [132].

Saliva has not been implicated in the transmission of HIV even after bites, percutaneous inoculation, or contamination of open wounds with saliva from HIV-infected patients [133, 134, 135, 136, 137 and 138]. Hepatitis B-positive saliva has also not been demonstrated to be infectious when applied to oral mucous membranes or through contamination of shared musical instruments or CPR training manikins used by hepatitis B carriers. However, it is not impossible that the mouth-to-mouth technique might result in the exchange of blood between patient and rescuer if there are open lesions or trauma to the buccal mucosa or lips. Diseases such as tuberculosis, herpes, and respiratory viral infections are potentially spread during mouth-to-mouth ventilation. Infections thought to have been transmitted by CPR include Hel-icobacter pylori [139], Mycobacterium tuberculosis [140], meningococcus [141], herpes simplex [142], Shigella [143], Streptococcus [144], Salmonella [145], and Neisseria gonorrhea [146]. There have been no cases reported of transmission of HIV, hepatitus B virus, hepatitis C virus, or cytomegalovirus [146]. The impact of these facts is different for lay people and health care professionals, and different for those carrying infection and for those at risk of infection [147].

The distinctive function of the ICU is to serve as a locus of concentrated expertise in medical and nursing care, life-sustaining technologies, and treatment of complex multiorgan system derangement. Historically, it was the development of effective treatment for otherwise rapidly fatal arrhythmias during acute myocardial infarction that impelled the medical community to establish ICUs [148]. Rapid response by medical personnel has been facilitated by constant professional attendance and the development of widely accepted guidelines for resuscitation. Each
member of the professional team is expected to respond in accordance with these guidelines.

The skills necessary to perform adequately during a cardiac or respiratory arrest and to interface smoothly with ACLS techniques cannot be learned from reading texts and manuals. CPR courses taught according to AHA guidelines allow hands-on experience that approximates the real situation and tests the psychomotor skills needed in an emergency. All those who engage in patient care should be trained in BLS. Those whose duties require a higher level of performance should be trained in ACLS as well. As these skills deteriorate with disuse, they need to be updated. It is worth noting that there is no “certification” in BLS or ACLS. Issuance of a “card” is neither a license to perform these techniques nor a guarantee of skill, but simply an acknowledgment that an individual attended a specific course and passed the required tests. If employers or government agencies require such a card of their health workers, it is by their own mandate.

The ensuing discussion of BLS and ACLS techniques follows the recommendations and guidelines established by the AHA and presented in a supplement to volume 112 of Circulation [17].

BLS is meant to support the circulation and respiration of those who have experienced cardiac or respiratory arrest. After recognizing and ascertaining its need, definitive help is summoned without delay and CPR is initiated.