[Potency of CPR without artificial breathing]

Recent experimental studies reported by several independent groups demonstrated that in the initial interventions of cardiopulmonary resuscitation (CPR), airway protection (A) and artificial breathing (B) are not essential for successful recovery from cardiac arrest. In this study, we reviewed and compared those reports to investigate individual effects of A and B on initial CPR. Airway protection: Spontaneous gasping during cardiac arrest is accompanied by upper airway protective reflexes such as head tilt and open mouth. Gasping promoted CO2 elimination from the nose in animals without A. Breathing: Gasping and precordial compression generated ventilation up to 150 and 100 ml.kg-1. min-1 respectively during cardiac arrest. Arterial blood gas analyses demonstrated that CPR without B developed hypercarbia, but maintained oxygen tensions in physiological levels. The frequency of chest compression is in the range of high frequency ventilation, which might allow for successful oxygenation regardless of limited tidal volumes. A series of experimental studies for CPR without A or B call for establishment of a simple CPR method for bystanders, namely "Just compress the chest".