The American Heart Association's (AHA) revised "Standards and Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiac Care (ECC)" recommend that bicarbonate be used ". . . only at the discretion of the physician directing the resuscitation." Reliance upon arterial blood gases is suggested for bicarbonate administration to the patient in cardiac arrest. However, recent literature suggests that arterial blood gases may not reflect the severe cellular acidosis that occurs at the tissue level during cardiac arrest. This article reviews the literature support for this recommendation and for the primary reliance upon hyperventilation to treat the acidosis of cardiac arrest patients. This is a very significant change in the management of the acidosis of cardiac arrest. As with most changes in traditional clinical practice, it will be difficult to overturn years of physician behavior.