Should calcium be used in cardiac arrest?

Calcium salts have been recommended for and used in the treatment of various forms of cardiac arrest for many years. Although calcium plays a major role in excitation-contraction coupling, it can have a deleterious effect in some processes of cellular injury. Clinical trials suggest that calcium salts are not effective in ventricular fibrillation and asystole, but that some patients with electromechanical dissociation may have a favorable hemodynamic response. Because of the potential risks of calcium salts, their use should be limited to specific subsets of patients with cardiac arrest.