Miniaturized chest compressor

Current American Heart Association guidelines call for continuous manual chest compressions for cardiopulmonary resuscitation. Chest compressions maintain critical levels of forward blood flow, including blood flow to the myocardium during cardiac arrest, to allow for successful resuscitation. The demand on rescuers is to ensure that compression is consistent, with appropriate force and depth, often under difficult conditions of rescue, evacuation, and transport. It is also of great moment that fatigue of the rescuer adversely affects outcomes. This evaluation was to compare two pneumatically driven devices, the Michigan Thumper (Michigan Instruments, Grand Rapids, MI), as an industrial standard, and the miniaturized chest compressor.

On a porcine model of cardiopulmonary resuscitation, alternating current fibrillation was induced for 7 mins, followed by 5 mins of chest compression. Arterial and right atrial pressures and end-tidal CO2 were measured. Coronary perfusion pressure was calculated as the difference between compression end-diastolic arterial pressure and right atrial pressure.

Threshold levels of coronary perfusion pressure (>15 mm Hg) and end-tidal CO2 (>10 mm Hg) for successful defibrillation were maintained with the miniaturized chest compressor. Consistently greater coronary perfusion pressure and end-tidal CO2 values were achieved with the miniaturized chest compressor in comparison with the Thumper.

The miniaturized chest compressor has the important potential advantage of minimal weight and, therefore, portability, without any reduction in effectiveness. To the contrary, it is potentially more effective than the much larger and heavier industry standard for maintaining circulation.