The effect of bicarbonate on resuscitation from cardiac arrest

Study objectives: This study attempted to determine the effect of bicarbonate administration on resuscitation in a porcine model of prolonged cardiac arrest. Design: After instrumentation, 26 swine were subjected to ventricular fibrillation for 15 minutes (16 animals) or 20 minutes (ten animals) with no resuscitative efforts. Interventions: Resuscitation attempts with open-chest cardiac massage and epinephrine were used in all animals after the arrest period. The experimental group was given sodium bicarbonate (3 mEq/kg), and the control group received 3% saline (5 mL/kg) at the initiation of cardiac massage. Measurements: Resuscitation success, hemodynamics, and arterial and mixed venous gases were compared in the bicarbonate and hypertonic saline-treated groups. Results: There was no difference in resuscitation rates between bicarbonate and nonbicarbonate-treated swine. After 15 minutes of ventricular fibrillation, six of eight bicarbonate-treated swine were resuscitated successfully compared with five of eight hypertonic saline-treated animals. None of the five bicarbonate-treated or five hypertonic saline-treated swine that underwent 20 minutes of ventricular fibrillation were resuscitated. The arterial and mixed venous pH values were significantly different in the bicarbonate-treated animals from values in the control group. There was no difference in systolic or diastolic blood pressures or myocardial perfusion pressure between the bicarbonate and hypertonic salinetreated animals. Conclusion: Despite correlation of arterial and venous acidemia, the use of sodium bicarbonate did not improve resuscitation from prolonged cardiac arrest.