Abstract 31: Comparison between Mechanical Active Chest Compression/Decompression and Standard Mechanical Chest Compression
Introduction. After cardiac arrest, uninterrupted chest compressions with restoration of myocardial blood flow facilitate defibrillation. Accordingly, decreases in intrathoracic pressure (ITP), following complete chest recoil, increase the venous return to the heart prior to the next compression. Several new devices have recently been introduced to facilitate chest compressions and some of them are able to perform active chest decompression. We compared the hemodynamic effectiveness of “LUCAS®” (Jolife, Medtronic, Sweden) with that of the conventional “Thumper®” (Model 1000, Michigan Instruments, Grand Rapids, MI)
Hypothesis. LUCAS®, able to produce active chest compression/decompression, might be more effective than the standard “Thumper®” for restoring circulation during CPR.
Methods. In 10 domestic pigs weighing 39 ± 2 kg, ventricular fibrillation (VF) was electrically induced and untreated for 5 min. Animals were then randomized to receive chest compressions with either LUCAS® or Thumper®. After 5 min of mechanical chest compressions, defibrillation was attempted with a 150 J biphasic shock. Coronary perfusion pressure (CPP) and end tidal CO2 (ETCO2) were measured by conventional techniques. Carotid artery blood flow (CBF) was assessed utilizing an ultransonic flowprobe, together with ITP, measured with the aid of a balloon tipped catheter advanced into the esophagus.
Results. Each animal treated with LUCAS® and 4 of 5 animals treated with Thumper® were successfully resuscitated. LUCAS® continuously produced negative ITP during the decompression phase (p < 0.05 vs Thumper®) and this was accompanied by greater CPP, ETCO2 and CBF compared to animals treated with Thumper®. Animals compressed with LUCAS® also had lesser broken ribs (p < 0.05). Table⇓
Conclusions. The mechanical chest compressor LUCAS® is able to produce greater negative ITP during the active decompression phase and therefore produces greater forward blood flow during CPR.