A computer controller for vest cardiopulmonary resuscitation (CPR)

The authors recently developed a cardiopulmonary resuscitation (CPR) technique in which the airways are obstructed automatically during each chest wall compression. Energy loss accompanying air convection from the lungs during chest wall compression is limited so lung volume and intrathoracic pressures are increased. This technique required the development of a simple controller device to govern the pressure applied to ribcage and abdominal vests together with controller airflow at the airway opening. Experiments with the controller device on eight mongrel dogs showed that cardiac output increased obstructed expiratory cardiopulmonary resuscitation (OECPR) by 19% relative to the cardiac output during standard vest CPR (61% of the prearrest cardiac output relative to 24%, respectively). Furthermore, the OECPR technique without adjunct ventilation resolved the hypocapnic respiratory alkalosis that developed during the standard vest CPR with no ventilatory support. The authors give background information on the obstructed expiratory vest CPR and describe the controller device for delivering this CPR method.