Transthoracic application of electrical cardiopulmonary resuscitation for treatment of cardiac arrest.

OBJECTIVE

Observational studies have shown that muscular stimulation contracting the thoracic cage may produce coronary perfusion pressures equal to manual chest compressions. This study examined electrical cardiopulmonary resuscitation for coronary perfusion pressures during ventricular fibrillation in a porcine model of cardiac arrest.

DESIGN

Prospective randomized controlled study.

SETTING

University affiliated research institute.

SUBJECTS

Domestic male pigs.

INTERVENTIONS

In seven domestic male pigs (40 +/- 2 kg), ventricular fibrillation was induced electrically and untreated for 10 secs. For each ventricular fibrillation episode, one of 16 electrical cardiopulmonary resuscitation stimulation protocols (pulse trains) or manual chest compression was applied. Each compression protocol was applied for 20 secs, followed by a defibrillation shock. The experimental procedure was performed across one or more randomized complete blocks. The electrical cardiopulmonary resuscitation pulse trains were defined by four two-level factors: pulse width (0.15 and 7.5 msec), pulse period (15 and 30 msec), train width (50 and 200 msec), and train rate (60 or 120 compressions per min). Pulse trains comprised two groups, based on pulse width (skeletal-based, 0.15 msec; cardiac-based, 7.5 msec).

MEASUREMENTS AND MAIN RESULTS

Train width was the significant design parameter for producing efficacious levels of coronary perfusion pressures for the skeletal-based electrical cardiopulmonary resuscitation pulse trains (p = 0.02). Both train width and train rate were significant design parameters for producing efficacious levels of coronary perfusion pressures for the cardiac-based electrical cardiopulmonary resuscitation pulse trains (p < 0.001, p = 0.5, respectively). Optimal skeletal-based and cardiac-based electrical cardiopulmonary resuscitation pulse trains were significantly better than ventricular fibrillation (p = 0.01, p = 0.01, respectively) and equivalent to manual chest compression (p = 0.2, p = 0.7, respectively) for sufficient coronary perfusion pressure levels.

CONCLUSIONS

Optimal skeletal-based and cardiac-based electrical cardiopulmonary resuscitation pulse train parameters generated levels of coronary perfusion pressure significantly greater than ventricular fibrillation and comparable with manual chest compression over a short interval of untreated cardiac arrest.