Abstract 2843: Epinephrine Reduces Cardiac Outputs Generated By Chest Compressions During Cardiopulmonary Resuscitation
Introduction. Epinephrine administered during CPR increases myocardial perfusion pressures and enhances myocardial blood flows. We sought to investigate the effects of epinephrine on cardiac outputs (CO) generated by chest compressions (CC).
Hypothesis. Administration of epinephrine during chest compressions will increase coronary perfusion pressure (CPP) with minimal effects on cardiac output.
Methods. In 14 domestic pigs weighing 40 ± 2 kg ventricular fibrillation was induced and untreated for 7 min. Animals were then divided to receive 4 min of either ``optimal” or ``conventional” CC. For ``optimal” CC, the anterior posterior diameter of the chest was reduced by 25% representing approximately 6 cm. Only 70% of this depth or approximately 4.2 cm represented ``conventional” CC. In each animal, epinephrine (30 μg/kg) was administered after 2 min of chest compressions. CO was measured with thermodilution technique, immediately prior and 2 min after administration of epinephrine. Chest compressions were performed with a conventional mechanical chest compressor.
Results. CPP significantly increased after administration of epinephrine, during both optimal and conventional chest compressions (p < 0.01). CO was significantly greater during optimal chest compressions in comparison to conventional chest compressions (p < 0.01). After administration of epinephrine, however, CO significantly decreased in both groups (p < 0.01). Table⇓
Conclusions. Administration of epinephrine significantly increases CPP during chest compressions. Increases in myocardial perfusion pressures are not accompanied by increases in CO, which is markedly reduced following epinephrine.