The routine use of sodium bicarbonate in patients with cardiac arrest has been discouraged, with the benefit of outcome evaluation. Current recommendations include an elaborate stratification of circumstances in which bicarbonate is to be used. The physiological and clinical aspects of bicarbonate administration during cardiopulmonary resuscitation in animal and human studies were reviewed. The onset of significant acidemia or alkalemia is associated with adverse system specific effects. The administration of bicarbonate may mitigate the adverse physiological effects of acidemia, improve response to exogenously administered vasopressor agents, or simply increase venous return due to an osmolar effect, resulting in increased coronary perfusion pressure. Likewise, bicarbonate may have adverse effects in each of these areas. The preponderance of evidence suggests that bicarbonate is not detrimental and may be helpful to outcome from cardiac arrest. An objective reappraisal of the empirical use of bicarbonate or other buffer agents in the appropriate "therapeutic window" for cardiac patients may be warranted.