Is there too much "pulmonary" in cardiopulmonary resuscitation?

Cardiopulmonary resuscitation (CPR) can be an effective life-saving technique. Basic life support with chest compressions and rescue breathing is taught in a standard, rigid fashion, as if all cardiac arrests were the same, in part because of practical educational considerations.1 It is quite likely that optimal CPR varies, depending on the specific underlying and ongoing pathophysiology and pathoanatomy. For example, chest compressions without rescue breathing seem to be the preferred telephone-directed CPR technique for sudden collapse ventricular fibrillation (VF) cardiac arrests.1,2 In contrast, rescue breathing is critical for resuscitation from a cardiac arrest secondary to acute asphyxia.3 Importantly, cardiopulmonary interactions certainly raise substantive issues during the low-flow circulatory state of CPR, as noted by Yannopoulos et al, in this issue of RESPIRATORY CARE.4 Readers of this Journal are quite familiar with the potential profound effects of cardiopulmonary interactions. These issues are especially pertinent in certain extreme pathophysiological circumstances, such as severe circulatory shock or ventilation with high mean intrathoracic pressure. High levels of positive end-expiratory pressure can impede venous return and decrease cardiac output and blood pressure. Rapid positive-pressure rescue breathing for severe life-threatening respiratory failure due to asthma can also impede venous return, and can even result in profound shock and death.5 During CPR for cardiac arrest in animal models, the cardiac output is quite low, typically 10–20% of the baseline cardiac output (even with excellent continuous, uninterrupted, forceful chest compressions—an ideal circumstance rarely applicable to real-life CPR).1,6–9