LUCAS - Lund University Cardiopulmonary Assist System

University dissertation from Department of Cardiothoracic Surgery, Clinical Sciences, Lund University

Abstract: Lund University Cardiopulmonary Assist System (LUCAS) is a mechanical device providing automatic 5 cm deep chest compressions and active decompressions back to normal anatomical position with a frequency of 100 per minute, and a duty cycle of 50%, i.e., LUCAS is constructed to give chest compressions according to the latest international guidelines in cardiopulmonary resuscitation (CPR). The aim of the thesis was to study cardiac arrest using different porcine models of ventricular fibrillation. Four hypotheses were formulated: 1. LUCAS-CPR is superior to manual CPR regarding coronary perfusion pressure (CPP) and return of spontaneous circulation (ROSC). 2. Hypothermic LUCAS-CPR is superior to normothermic LUCAS-CPR in treating prolonged ventricular fibrillation. 3. The rate of ROSC after prolonged ventricular fibrillation will increase if LUCAS-CPR is given before defibrillation, and if defibrillation is given during on-going chest compressions. 4. LUCAS-CPR will cause fewer rib fractures than manual CPR. LUCAS-CPR gave significantly higher rates of ROSC and significantly higher CPP than manual CPR. LUCAS-CPR combined with surface cooling to 34°C was superior to normothermic LUCAS-CPR during 1 hour of CPR for ventricular fibrillation. Defibrillation was more effective to obtain ROSC after prolonged ventricular fibrillation if chest compressions were done before the shock, and if the shock was given during on-going LUCAS-CPR. LUCAS-CPR caused significantly fewer rib fractures during 20 minutes of CPR compared to manual CPR.