Abstract 5: A New Miniaturized Chest Compressor
Introduction. After prolonged cardiac arrest, uninterrupted chest compression with restoration of myocardial blood flow facilitates defibrillation (2005 AHA Guidelines for CPR, Circulation 2005; 112:24). We recognized that such may best be accomplished with a mechanical device and especially so during transport. We therefore sought a lightweight, portable chest compressor which may be carried on the belt of the first response rescuer. This device contrasts with currently available large devices with high energy requirements.
Hypothesis. A Miniaturized Pneumatic Chest Compressor (MCC) weighing less than 2 kg will be as effective as the standard “Thumper” for restoring circulation during CPR.
Methods. In 10 domestic male pigs weighing 40 ± 2 kg, ventricular fibrillation (VF) was electrically induced and untreated for 5 minutes. Animals were randomized to receive chest compressions with either the MCC or a ThumperR (Model 1000, Michigan Instruments, Grand Rapids, MI) after 5 minutes of untreated cardiac arrest. After 5 minutes of mechanical chest compression, defibrillation was attempted with a 150 J biphasic precordial shock. Coronary perfusion pressure (CPP) and ETCO2 were measured by conventional techniques together with right carotid artery blood flow (CBF) utilizing an ultransonic flowprobe.
Results. Each animal compressed with the MCC and 4 of 5 animals compressed with ThumperR were successfully resuscitated. No significant differences in CPP or ETCO2 were observed between groups (Table⇓).
Conclusions. The Miniaturized Chest Compressor of small dimension and weight is as effective as the conventional Thumper for maintaining forward blood flow during CPR. (Patent in favour of the Weil Institute is pending)