It is well known that out-of-hospital sudden cardiac death is a leading public health problem. In the absence of early defibrillation, survival rates of patients with out-of-hospital cardiac arrest are dismal and have remained essentially unchanged. The guidelines advocate the same approach for 2 entirely different pathophysiological conditions: respiratory arrest in which severe arterial hypoxia and hypotension eventually lead to secondary cardiac arrest, and primary cardiac arrest in which the arterial blood is fully saturated with oxygen at the time of the arrest. Cardiopulmonary resuscitation (CPR) is traditionally defined as chest compressions plus ventilations. The need for chest compressions is unquestionable, while the need for mouth-to-mouth ventilations for cardiac arrest has been questioned. Recent observational studies underline the paramount role of chest compressions in an alternative way of CPR, compression only CPR. Public education and training in compression only CPR is much simpler. Compression only CPR may significantly increase bystander-initiated resuscitation efforts and thereby give patients a better chance of survival, given the reluctance of lay people to provide mouth to mouth rescue breaths. In view of the above, the principal question is, what barriers are delaying the guidelines from recommending compression only CPR? Perhaps the major problem is the difficulty to change the paradigm. For decades, the "ABCs" (airway, breathing, and circulation) have been advocated for bystander basic life support, making it extremely difficult to transform the so ingrained in the popular understanding "ABC" to "AC"
