[Calcium antagonism - a new pharmacologic principle in resuscitation. Comparison of calcium and calcium antagonists]

In cardiopulmonary resuscitation (CPR) of dogs after anoxic cardiac arrest the effect was compared of epinephrine (E) alone (50 micrograms/kg, n = 11) to that of epinephrine plus calcium chloride (20 mg/kg) and of diltiazem (150 micrograms/kg 30 sec after E and 25-50 micrograms/kg/min after restoration of spontaneous circulation). The success of resuscitation was 100% in the epinephrine group and the diltiazem group but only 70% in the calcium group (p less than 0.05). In the phase of restoration of spontaneous circulation, calcium increased the critical hemodynamic parameters leading to O2 consumption whereas diltiazem decreased them (heart rate, LVdp/dt max, afterload). Diltiazem improved the oxygen demand/supply ratio by increasing coronary blood flow significantly and decreasing oxygen demand. The significant increase in CPK activity reflected unfavorable oxygen balance in the calcium group. It is concluded that calcium should not be given in CPR, although calcium antagonism represents a promising new pharmacological principle in this field.