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 saline-treated animals.

CONCLUSION

Despite correlation of arterial and venous acidemia, the use of sodium bicarbonate did not improve resuscitation from prolonged cardiac arrest.