Abstract 256: Active Compression Decompression CPR With 5 Centimeters Lift and an Impedance Threshold Device Significantly Improves All Markers of Cerebral and Cardiovascular Hemodynamics and Blood Flow After 8 Minutes of Standard CPR

Abstract

Introduction: Active compression decompression (ACD) CPR performed along with the use of an impedance threshold device (ITD) has been shown to improve cerebral and coronary hemodynamics compared to standard CPR (SCPR). In this study, we demonstrate that ACD+ITD provides significant benefits even when initiated after 8 minutes of SCPR as measured by cerebral and cardiovascular perfusion pressures, cerebral oximetry, and blood flow as determined by neutron-activated microsphere analysis. Methods: Ventricular fibrillation was induced in 10 female Yorkshire farm pigs (40.6 ± 0.7 kg) and left untreated for 6 minutes. All animals then received 8 minutes of SCPR, followed by ACD+ITD for an additional 6 minutes. CPR was performed at a rate of 100 compressions/minute at a depth of 20% (~ 5 cm) of anteroposterior chest height. During ACD there was also an active lift component of 5cm beyond resting chest position. Microspheres were injected 4 minutes after starting SCPR and 2 minutes after starting ACD+ITD. Millar catheters were placed to measure right atrial, aortic, and intracranial pressures and NIRS was used to assess regional cerebral oxygenation. 3 minute averages obtained prior to the end of each intervention were compared with Student’s t-test and reported as mean ± SEM. Results: Mean coronary perfusion pressure and cerebral perfusion pressures were significantly improved during ACD+ITD (p<0.002, Fig 1). ACD+ITD also resulted in a 7% increase in cerebral oxygenation (47 ± 2 vs 50 ± 2%, p<0.001), a 30% increase in cerebral blood flow (0.3 ± 0.1 vs 0.4 ± 0.1ml/min/gm, p<0.004), and a 30% improvement in coronary blood flow (0.6 ± 0.1 vs. 0.9 ± 0.1ml/min/gm, p<0.004). Conclusion: This study reveals the significant benefit of ACD+ITD as measured by currently available invasive and non-invasive blood flow measurements following 8 minutes of SCPR. Initiating ACD+ITD earlier can only result in further improvement of these parameters and offer a higher likelihood of survival.