Abstract 435: Controlled Sequential Elevation of the Head and Thorax Rapidly Achieves 50% of Baseline Cerebral Perfusion Pressure During Active Compression-Decompression Cardiopulmonary Resuscitation With an Impedance Threshold Device in a Swine Model of Cardiac Arrest

Introduction: Controlled sequential elevation of the head and thorax (CSE) during active compression-decompression (ACD) CPR with an impedance threshold device (ITD) has previously resulted in sustained nearly normal cerebral perfusion pressures (CerPP) of 75 mmHg. However, the optimal speed of CSE remains unknown. It is also unknown if some CPR is needed to ‘prime the system’ prior to maximal CSE. Hypothesis: An optimized CSE will achieve 50% of baseline (50% BL) CerPP in Methods: Female farm pigs were intubated and anesthetized. Central vascular and intracranial access were obtained. After 8 min of untreated ventricular fibrillation, pigs were placed in a customized elevation device (CED). After 2 min of ACD+ITD CPR at the lowest CED level to prime the circulation, pigs were randomized to CSE over 1) 4-min or 2) 10-min until the CED reached its highest level. ACD ITD CPR was performed for a total of 19 minutes. Based upon initial results, two additional groups of pigs were studied: one with a CSE over 2-min after the 2 min ‘priming’ step, and the other with CSE over 24-sec without priming. The primary outcome was time in minutes to achieve 50% BL of CerPP values. Results: There were six pigs per study group (4-min, 10-min, 2-min and 24-sec). The 4-min CSE group achieved 50% BL CerPP faster (min ± SD) than the 10-min CSE group (2.53 ± 1.26 vs 5.98 ± 3.16 , p=0.04, Figure 1). The 2-min CSE group CerPP was similar to the 4-min group (2.36 ± 2.18, p=0.92). The time to 50% BL CerPP trended 4 min faster in the 2-min CSE group versus the 24-sec CSE group (6.6 ± 6.73, p=0.16), as shown in the figure. With CSE, CerPPs increased over time in all groups. All pigs were resuscitated. Conclusions: A 50% BL CerPP value was achieved in