Abstract 88: Gravity-Assisted Head-up Cardiopulmonary Resuscitation Improves Cerebral Blood Flow and Perfusion Pressures in a Porcine Model of Cardiac Arrest
Introduction: Compressing the chest during standard cardiopulmonary resuscitation (CPR) increases arterial and venous pressures simultaneously, thus reducing the possibility of a cerebral perfusion gradient during compressions. We hypothesized that CPR with the head up at 30° performed with an enhanced CPR method using the LUCAS-2 for active compression decompression (L-CPR) and an impedance threshold device (ITD) would improve cerebral perfusion by lowering intracranial pressure (ICP) without impairing hemodynamics.
Method: Twelve female pigs (39±0.6 kg) were sedated, intubated, anesthetized with isofluorane, paralyzed with succinylcholine (93.3 μg/kg/min) and placed on a tilt table. After 6 minutes of untreated ventricular fibrillation and 2 minutes of CPR, 6 minutes of L-CPR+ITD at 0° supine were performed, followed by 6 minutes of L-CPR+ITD at 30° head up tilt (HUT) and then by 6 minutes of L-CPR+ITD at 30° head down tilt (HDT). Neutron activated microsphere were used to measure vital organ blood flow on 5 pigs and were injected 2 minutes after each change of position. Hemodynamic parameters, ETCO2, ICP, calculated coronary perfusion pressure (CPP) (diastolic aortic - right atrial pressure) and cerebral perfusion pressure (CePP) (aortic - ICP) were measured continuously. Data were compared over the last 2 minutes of each intervention on the 12 pigs. A paired t test was used for statistical comparisons (0° versus 30° head up and 0° versus 30° head down). Data are expressed as mean ± SEM, blood flow in ml/min/g and pressure in mmHg.
Results: CPP and CePP were higher with 30°HUT and greatly diminished with 30°HDT. CPP was 18±2 at 0° vs. 28±2 at 30°HUT (p<0.001) and 7±3 at 30° HDT (p<0.001). CePP was 17±2 at 0° vs. 32±2 at 30°HUT (p<0.001) and 0±2 at 30° HDT (p<0.001). Brain blood flow was 0.18±0.05 at 0° versus 0.25±0.03 at 30°HUT (p=0.01) and 0.10±0.02 at 30° HDT (p=0.15). Heart blood flow was 0.13±0.05 at 0° versus 0.18±0.05 at 30°HUT (p=0.03) and 0.13±0.06 at 30° HDT (p=0.97). There were no significant differences in mean aortic pressure or ETCO2 between interventions.
Conclusion: L-CPR+ITD combined with 30° HUT improve cerebral and heart perfusion and perfusion pressures during CPR. Further studies are warranted to explore this novel intervention on survival.
Author Disclosures: G. Debaty: None. S. Shin: None. A. Metzger: Employment; Significant; Advanced Circulatory Systems, Inc.. H. Ryu: None. T. Kim: None. J. Rees: Employment; Significant; Advanced Circulatory Systems, Inc.. S. McKnite: None. T. Matsuura: None. M. Lick: Employment; Significant; Advanced Circulatory Systems, Inc. D. Yannopoulos: Research Grant; Significant; NIH 1R01HL123227-02; R01HL108926-04. K.G. Lurie: Employment; Significant; Advanced Circulatory Systems, Inc.. Ownership Interest; Significant; Advanced Circulatory Systems, Inc..
- © 2014 by American Heart Association, Inc.