PV Loops and REBOA During Hemorrhage and Resuscitation

Abstract Retrograde Endovascular Balloon Occlusion of the Aorta (REBOA) is frequently used in hemorrhagic shock to facilitate resuscitation. In theory, aortic occlusion increases afterload and focuses perfusion to the coronary arteries and great vessels; also to focus perfusion to the brain. It is, however, unknown exactly how and to what extent REBOA impacts cardiovascular parameters such as preload, afterload and contractility, or coronary artery blood flow. It is also not known how these parameters evolve over time during REBOA as it is shifted from fully to partially occlusive, or weaned down entirely. We aim to use left ventricular Pressure-Volume (PV) loop analysis and directly measure coronary flow in swine as they descend into hemorrhagic shock, are resuscitated with full aortic occlusion with REBOA, transitioned to partial aortic occlusion with REBOA, and then weaned completely off of the REBOA and are resuscitated. We will examine, specifically, measures of preload, afterload, contractility and coronary blood flow during each study time period (baseline, hemorrhagic shock, full aortic occlusion, partial aortic occlusion, and post-occlusion during resuscitation).