Abstract 17060: The Effect of Resuscitation Position on Cerebral and Coronary Perfusion Pressure During Mechanical Cardiopulmonary Resuscitation in Porcine Model

Abstract

Objectives: Mechanical compression devices can allow us to select a positon during transport with cardiopulmonary resuscitation (CPR) in a small space (like elevator) to reduce the length of stretcher cart. It is unclear, however, whether resuscitation position is associated with cerebral perfusion pressure (CePP) or coronary perfusion pressure (CoPP). Methods: This is a randomized crossover experimental trial using female farm pigs (n=12) (42 ± 3kg) sedated, intubated, and paralyzed on a tilt table. After surgical preparation, 6 minutes of untreated ventricular fibrillation was induced followed by 3 minutes in 0° supine position as a stabilization period with mechanical CPR device (M) and an impedance threshold device (ITD). Then, 5 minutes of M-CPR+ITD was performed in a position randomly assigned to either head-up tilt at 30°, 45°, or 60°, supine, or head-down tilt at 30°, 45°, or 60° followed by 5 minutes of M-CPR+ITD in crossover position to the other. We measured and compared the CePPs and CoPPs at the positions using ANOVA with Duncan post-hoc test. Results: Baseline hemodynamic parameters among pigs were not different. From head-down to head-up by elevation of angle, mean aortic pressures slightly decreased and intracranial pressure significantly decreased. With 60°, 45°, 30° head-down, 0°(supine), and 30°, 45°, 60° head-up positioning, CePPs increased linearly as follows: 2.4± 3.1, 9.3±3.9, 16.5±5.0, 27.0±2.3, 35.1±1.2, 39.4±12, 39.9±1.5mmHg respectively (p<0.001 by ANOVA and all significant for post-hoc test). CoPPs was peak in head-up 30 °: 12.9± 4.2, 13.3±5.0, 12.8±2.9, 18.1±2.0, 30.3±1.5, 24.1±1.7, 26.5±1.9 mmHg respectively (p<0.001 by ANOVA post-hoc test except between head-down -30° and -65°). Conclusion: Mechanical CPR position was associated with different cerebral perfusion pressure by head-up angles. The head-up 30° showed the peak coronary perfusion pressure.