Comparative study of three methods of resuscitation: closed-chest, open-chest manual, and direct mechanical ventricular assistance.

Presented are the results of a comparison study of three forms of circulatory support during ventricular fibrillation: closed-chest compression (CCC), open-chest manual compression (OCMC), and direct mechanical ventricular assistance (DMVA). DMVA is a method of circulatory support using a bell-shaped device that is affixed to the heart by apical suction and that alternately compresses and expands the ventricles. CCC produced a cardiac index (CI) of 780 mL/min/m2 (19% of control) with a mean arterial pressure (MAP) of 26 mm Hg (23% of control). Both forms of direct cardiac compression produced higher values. OCMC at 60 compressions per minute (CPM) produced a CI of 2,069 mL/min/m2 (52% of control) with an MAP of 50 mm Hg (45% of control). DMVA at the same rate produced a CI of 2,780 mL/min/m2 (70% of control) with an MAP of 72 mm Hg (65% of control). The values for DMVA at 60 CPM were significantly higher than for OCMC at 60 CPM (P less than .005 for CI, and P less than .0005 for MAP). Changing from standard CCC to DMVA at 90 CPM produced the greatest hemodynamic improvements: MAP increased by 250%, and CI increased by 340%. With DMVA at 90 CPM, the systolic pressure, stroke index, and CI were not statistically different from control, prearrest values.